## Thursday, December 10, 2020

### Checking Sight Reduction With CelestialTools.exe

CelestialTools.exe is a free PC program that solves many problems in cel nav and other areas. It was written by the late Stan Klein, navigator, teacher, and friend. It was written for USPS students and instructors, but Stan decided to share it with the public several years ago and ask us to host it, which we were happy to do.  It is a wonderful tool for learning cel nav, especially with regard to one unique function it includes called "SR Methods and Fix." Download celestial tools and its manual.

Below is the graphic menu to the program (Windows only). The function at hand now is far left of the middle row.

 Figure 1 Splash screen index.  (Click any image for a better view.)

Here is the motivation for this note. A student working a sight reduction using the NAO Sight Reduction tables got the wrong answer, and submitted this form for us to check. This is one of the Starpath work forms, available online as blank forms. The instructions and examples are in a separate book.

We are happy to make such checks for our students, but we try to encourage them to use CelestialTools as it is a way to find mistakes much faster than waiting for our response. This note here is just a reminder about how this works. You can use it to check any type of sight reduction.

 Figure 2. An NAO form with wrong data.

This has the wrong answer. Recall that a sight reduction means we start with Lat, LHA, and dec and end up with Hc and Zn. Here we have Lat = 45N, dec = N 19º 23.9', and LHA = 327.  We can find the right answer with the "SR Methods and Fix" tool, shown below, by selecting a direct computation called here "Law of Cosines."

Enter LHA = GHA and use Lon = 0. Enter dec and Lat and then choose your sight reduction on the right and click it.  Then you have to study the output carefully to see what the individual steps of the solution should be—although this does not really apply to the Law of Cosines solution.

 Figure 3 The right answer by direct computation.

This gives the answer of Hc = 52º 34.9' and Hc = 122.3, which is not what was found by the NAO table form shown above because it was not filled out correctly.

Now we look at the option called NASR (Nautical Almanac Sight Reduction) which is these days more commonly called the NAO sight reduction tables, standing for Nautical Almanac Office of the USNO.

 Figure 4. The NAO solution (called here NASR).

Referring back to Figure 2, we see that he got the parameter A correct (22º 39'), but then failed to round it properly to 23 in Box 2. The bar in box 2 is a reminder to round these values. Then when transferring the data for F, he changed the 59 to a 39, and so carried on with A = 22 and F = 39 when this should have been A = 23 and F = 59.

Below is the result using wrong input, which was actually extracted properly, followed by the table showing the right values.

 Figure 5. NAO Table selection showing student's wrong entry.

 Figure 6 Right data from NAO tables.

When these values are used to complete the process the NAO results are Hc = 52º 35 and Hc = 122.3, which is within 0.1' of the best solution. This agreement is better than average. The NAO solution will generally be right on Hc to within ± 0.4' and will usually have the right Zn to a tenth or two.

We encourage everyone who is practicing with sight reduction of Pub 249, Pub 229, NAO or even more exotic older tables to have a look at this tool. It will save you a lot of time.

Here for reference is the same sight reduction done by Pub 229 and then by Pub 249.

 Figure 7. Pub 229 solution details.

 Figure 8. Pub 249 solution details.  In our cel nav course we interpolate the d-corr in 249, so we may differ by a tenth or two on Hc. He follows the official rules and rounds the declination.

## Tuesday, November 17, 2020

### How to Report Nautical Chart Corrections

One great virtue of electronic charts is their ability to be updated quickly by both NOAA's Office of Coast Survey (OCS), who makes the charts, and then the mariners who use them on the water. Electronic Navigational Charts (ENC) are updated weekly by OCS. All type-approved ECDIS (electronic chart display and information system) software as well as many ECS (electronic chart system) used by recreational mariners such as OpenCPN, Coastal Explorer, and Time Zero products offer an automated chart update service built right into the navigation software.

You can configure the nav programs to check for new charts every time you start the program, or you can update manually. Then if you are online at the time, the program logs into the right NOAA web page, checks for latest charts, and downloads new ones. NOAA provides the needed application programing interface (API) for programmers to use for this.

To illustrate the power of modern chart updating options, we take a look at how mariner's can take part in the process with what is effectively "crowd sourced" chart updating. We will look over the submission process for a user reported chart correction, and then follow through on it showing up in subsequent charts. We posted an earlier article on this process featuring a UKHO app designed for this. The US counterpart described there has since changed to what we show here, but the UKHO app is still available, and as far as we know could still be used to report comments on US charts, although the procedure shown here is the most direct.

What led us to return to this topic is we ran across a prominent naming error on ENC number US4WA11M (Puget Sound, Northern Part) that mis-labeled Montlake Cut at the west end of the Ship Canal that leads from the Puget Sound via the Ballard Locks into Lake Washington. On that chart it was called Montauk Cut—a famous maritime name for sure, but from NYC, not Seattle. Chart US4WA11M is scale 1:80,000, which is within the scale band 5 that spans scales of 1:50,000 to 1:150,000.

Here is the location we discuss within Puget Sound, followed by the object of interest shown on a chart.

This is the object as we first found it, with an insert showing the chart ID. This is viewed in OpenCPN, showing part of the "cursor pick" display seen when right clicking the Cut—this is the way you access object data on an ENC. The more general chart info shown is usually at the bottom of the display, seen with a click on the chart bar.

Montlake Cut can also be seen on scale band 5 chart US5WA13M, which is 1:25,000. If we zoom in to that scale we see that the Cut and Bridge are labeled correctly on that chart, so the only issue is US4WA11M.

As noted above, at one point NOAA/OCS had a dedicated webpage for reporting chart errors, but they have updated that, now combining chart error reports with their generic page for comments and questions that we find at

At this page, we select the Report an Error tab, and then just go down the line of entries.

There is a full NOAA interactive catalog in the right side panel, so you can find the exact Lat-Lon of the error with a button click. You can then include a screenshot of the error.

I do not know how long the error on US4WA11M was there, but I noted it on Monday, Nov 2, 2020 and sent in that form at about noon, Seattle time.  I was surprised to then get this back at 3:35 PM the same day:

From: NOAA Coast Survey Customer Response for Ticket #148408

3:35 PM Monday, Nov 2, 2020

Thank you for your inquiry into NOS products.  You are right, the name of the waterway was incorrect on US4WA11.  It has been revised in our database from Montauk Cut to Montlake Cut.  An update for US4WA11 (Edition 41, Update 7) should be available for download within a week.  Again, I'd like to extend my thanks to you for pointing out this error, so that it could be corrected.

Sincerely,

[name given]

Original Message:

-----------------------------------

"Good day, I would like to point out that on US4WA11 the Montlake Cut is misprinted as "Montauk Cut." This does not show up on US5WA13, as noted in the attachments. Please let me know that you have received this, and if you can, please give me an estimate of when we might expect this to be corrected.  Thanks very much. David Burch / Starpath School of Navigation / Seattle"

I am not sure when the actual update was made, but three days later on thursday we checked by doing a chart update for US4WA11M, and found the following:

So we see that it was indeed already fixed!  The new one is edition 41 /7. We can go the charts list to check when it was actually made (see link at www.starpath.com/getcharts):

It looks like the new update was issued on the same day of the report and actually built into the zipped ENC file on the next day.

I doubt we can expect that type of turn around in general, unless it is a simple one like this one that is easy to see and fix. But they do have the chance to issue a new update every week.

If you see things on a chart that are not right, or you have documented info to improve the charted data, then this is an easy way to submit it. Our feeling has always been that even though the ENC take some practice to get used to, in the end they will be superior to the RNC and offer mariners very much more information about the waterways.

Note added Nov 23:  Another way to follow up on your proposed correction is a new webpage they have on  weekly chart updates:

It takes a bit of practice, but you can look for updates per date nationwide or home in on specific charts or specific weeks.  A nice new edition to these modern times of weekly updates.  This may not be an advertised public site yet, but it is active.

Before submitting your proposed correction, it could be, depending on the correction, useful to check the latest USCG Weekly Notice to Mariners to see if the error has already been reported. And indeed, if the error is potentially hazardous to navigation, you might also report it to the Aids to Navigation office of the local USCG.

We have related ENC notes online at  Naming and Boundary Conventions in ENC.

For more details on the structure and use of ENC, see Introduction to Electronic Chart Navigation.

## Wednesday, November 11, 2020

### Into the Weeds with Abbreviations

There is a nuanced twist to navigation terminology that is ever more likely to be confronted... if you might care to ponder such things. It relates to a hierarchy in the specificity of abbreviations.

mb, Pub., WA are abbreviations. We write them as letters and then read them or pronounce them as the words they stand for, "millibars," "Publication," "Washington."  We can think of these as abbreviations, level 1.

GPS, ENC, COG are initialisms.  They are abbreviations we read and pronounce letter by letter, without saying, or maybe even knowing, what they stand for. We might call these abbreviations, level 2.

And then there is RADAR, ECDIS (pronounced "ekdis"), ATON (pronounced "ay-tahn"), which are acronymsThese are abbreviations that have been elevated to actual words that we pronounce as they are spelled.  Level 3!

Beyond this tidy arrangement, there is at least one loose cannon floating around the nav station.

NMEA, representing the National Marine Electronics Association, is often used as an acronym, which for some unknown reason is commonly pronounced "neema," which has nothing to do with what was once an unambiguous acronym (NIMA) for National Imagery and Mapping Agency  (1996 to 2003) that had replaced the Defense Mapping Agency, known by the initialism DMA.  NIMA was replaced with the NGA, the initialism for National Geospatial Agency, which serves an expanded function today, including the production of many useful nav pubs.

Years ago we proposed the name "erble" be used to elevate the abbreviation for electronic range and bearing line (ERBL) to an acronym. This does make reference to it more tidy,  but I am not sure if this ever caught on much. The longer the abbreviation, the more attractive an acronym becomes.

We got into this abbreviation minutiae today as we prepare our new online course on echart navigation, which focuses on ENC, electronic navigational charts. These are the vector charts that will replace all traditional paper charts and RNC (raster navigational charts) by the end of 2024, which is not that far away — it is now Nov 10, 2020, and many folks are at this moment well aware of  how long 4 years is!

Everything displayed on an ENC is an object, and every object is described by several attributes. Every object on the chart has a 6-letter abbreviation: landmark is LNDMRK, lateral buoy is BOYLAT. We learn what these attributes are when reading an ENC by clicking the object, called a cursor pick, which brings up a list of the objects at that point (usually several) as well as their attributes.

The attributes are also each given a 6-letter abbreviation. Thus, object BOYLAT has attribute BOYSHP (buoy shape), which has 8 possible values; attribute CATLAM (category of the lateral mark), which has 4 possible values; plus attributes for color, color pattern; etc.  There are 27 possible attributes of an object BOYLAT, which you can see defined at this online
ENC Object Catalog from Caris.

One of the first things we might note on that wonderful Caris reference, is they call the abbreviations "acronyms." For the most part, this is not right. We might get by with BOYLAT or CATLAM, but what about the crucial object used to describe rocks: UWTROC (underwater/awash rock). The vast majority of the abbreviations for objects and attributes are awkward at best to pronounce. Caris cannot be blamed for their use of the term. The International Hydrographic Organization  standard for ENCs (IHO S-57)  calls them "acronyms."

The point at hand here is that some abbreviations for objects and attributes will nevertheless inevitably become acronyms right out of the box, such as the attribute that nearly all objects have called SCAMIN (scale minimum,  maybe pronounced "ska min"). You must be zoomed into a scale equal to the SCAMIN or larger in order to see the object on an ENC. Recall that chart scales are defined as ratios: 1:40,000 (1/40,000) is a larger scale (fraction) than 1:80,000 (1/80,000). A lateral beacon (BCNLAT) with a SCAMIN of 44,999 will show up on a 1:40,000 display, but will disappear off the chart when you zoom out  to 1:80,000.

But I wander into the charting here, when the topic is abbreviations. The point is this: as we learn more of the 500 ENC objects and the 400 ENC attributes that can be used to describe them, we will first confront the fact that they look the same, each abbreviated with 6 capital letters, then we will most likely bump around a bit as we decide which of these should be honored with acronyms, and if we want an acronym for an abbreviation we can't pronounce, what word do we invent for it—in the spirit of NMEA.

If we have friends working in the government, we can ask them for help. They are experts at this... think of NOAA (noah), but that is just an ice crystal on the tip of the iceberg of government speak.

For completeness, I might note that the IHO has a standard for what must be in an ENC called IHO S-57 and another standard on how this information should be presented to the mariners, which is called IHO S-52. In the latter they discourage the use of the abbreviations for objects and attributes in lieu of  full names that they refer to as "human readable language."

Consequently, many echart programs do not use the abbreviations at all, however, my own work with ENC has shown a certain value to having these available. OpenCPN, for example, uses both the abbreviations and the full names for the objects, but only abbreviations for the attributes. Other programs do not use abbreviations at all.

## Saturday, September 26, 2020

### Detecting Fast Winds Aloft... and why we care

The winds aloft at about 500 mb (18,000 ft) play a key role in the winds we ultimately feel on the surface. The relationship is discussed in our textbook Modern Marine Weather. In short, the direction of the winds aloft tell us which way the surface Lows will approach us, and the speed of the winds aloft are a measure of the speed of the surface Lows (about 30 to 50% of the winds aloft speeds) as well as the severity of the surface winds we can expect.  The seminal explanation of the practical relation between winds aloft and surface winds is by Joe Sienkiewicz and Lee Chesneau.

Short of having an actual map of the winds aloft (which is easy to come by if we have wireless connections), we can gage both speed and direction from visual observations. Again, I refer to our text for details, but one way to spot direction is to note that the winds make waves in high cirrus clouds, much as wind makes waves in water. These waves show up as fine ripples in cirrocumulus clouds, called mackerel sky. The direction of the winds are, as is the case with water waves, perpendicular to the waves,  inline with the motion of the waves.

The speed of the winds aloft can be judged from other cirrus cloud patterns, such as prominent mare's tails. The very existence of a prominent and persistent wave pattern is some indication of at least a well defined wind pattern, but a more positive sign is the topic at hand. Namely, if you can actually see the high cirrus clouds moving, then the winds must be fast.  We mention this in several books, but this is not a very common observation, although we do indeed often see cirrocumulus in neat wave patterns.... as if waves in sand—as opposed to the much broader and more common patterns seen in altocumulus waves.

Note that most internet discussion and many books and some glossaries assign "mackerel sky" to altocumulus patterns, and there is no particular problem with that, but those clouds (waves in altocumulus) are not forecasters of strong winds, and not what was meant in the old saying "Mackerel skies and mare's tails make tall ships set low sails." This refers to  cirrocumulus patterns, indicators of the winds aloft.  Altocumulus patterns are determined mostly by boundary layer winds (~850 mb) that reflect what is going on now, not what is coming over the horizon.

Actually, let me take that back. There is a problem with the misidentification of the clouds that go with that famous forecasting jingle. Namely it dilutes our ability to do useful onboard forecasting based on what we see alone without weather maps or official forecasts at hand. In short, to use modern jargon, such discussion is fake news that can lead us astray. In any event, once you see that error in place, it is fair warning to be careful about other things stated in that reference. Sometimes we need to make the difficult distinction between high-end altocumulus and cirrrocumulus. See notes at the end about cirrocumulus v. altocumulus cloud waves. The importance of cirrus clouds for forecasting was known in the late 1800's.

The difficulty with spotting the cloud motion at sea is we need a reference to judge the motion by. Here on land, and in the sample below we have a building to use.

To follow up on this observation, which was made in Seattle at 1700 PDT, Sept 25, 2020, (00z on Sept 26),  we can go to the FTPmail folder of weather maps. Strangely enough, the OPC, which makes these maps, do not post the most recent 500-mb map on their own web page. They include a 24h and 48h forecast instead, but we can get the map valid at 00z 9/26 from the link above. At that link, go to Pacific / Upper Air Charts / 500 mb / Most Recent, which is shown below.... you will of course not see this when you do it as this will no longer be the most recent!

We see that the winds aloft we were viewing to the S at the moment could be as large as some 85 kts (exact values not clear as they are not labeled overhead and I have not tried to compute how far south these were at 40º high in the sky). The model winds on this map, however, are indeed high winds aloft speed (average may be closer to 60), although they can be much higher (>100 kts), but on the average they are lower.

If we look at the surface analysis at this time, we do not see much activity as shown below.

But the forecasts for the next two days do show a large storm developing in the Gulf of Alaska.

By this time, the winds aloft have backed down to the SW from the westerlies we were observing, a direction you can discern in the surface forecast from the orientation of the isobars in the warm sector of the accompanying frontal wave—and they are predicted to get even faster.

We won't see the effect on high clouds here in Seattle as, our winds aloft will be from the NW at moderate speeds, and we are well sheltered from that Low, but anywhere within that great sweep of the SW winds aloft, S to SE of the Low, should show some pretty dramatic cirrus patterns.

__________________

Cirrocumulus waves vs. Altocumulus waves.

Here are a couple sample comparisons from the remarkable WMO International Cloud Atlas.

The altocumulus above right are high ones where the identification becomes harder, but this example shows what we often see in altocumulus waves, namely indications of many different wind directions. This is a giveaway that this sky does not reflect the high winds, which will typically present a consistent, unique direction... although all such wave patterns are transitory.

## Friday, August 14, 2020

### MHW on ENC

The value of mean high water (MWH) at a specific location on a chart can be a crucial number in marine navigation. We need it to figure how far we can see a light at night, and we need it to figure what a bridge clearance will be. It is also needed to know whether certain rocks will be visible or not at various stages of the tide. These are all basic safety considerations we face in routine navigation.

MHW plays these roles because MHW is the height datum used on US nautical charts, which is the zero point for light heights and bridge clearances. Note this is not the same as the elevation datum used for elevation contours and spot elevations shown on charts. The elevation datum is mean sea level (MSL), which for most  practical purposes can be considered equal to the mean tide level, halfway between MLW and MHW.

Strangely enough, the important values of MHW are not listed in the standard NOAA Tide Tables (see endnote), but they are listed on every printed nautical chart and their RNC counterparts. The data appear in a table called Tidal Information. There are generally several values listed for points across the chart.

As we transition into ENC, however, we notice the MHW data are not so readily apparent. In fact, we get MHW from an ENC in a rather subtle manner. Namely the green foreshore shown on a chart is a specified depth area (DEPARE) object whose two bounding contours are the sounding datum (tide = 0) on the water side, and the height datum (tide = MHW) on the land side. The latter is effectively the drying height of the land at tide = 0, thus it is presented as a negative contour height equal to MHW.  See Introduction to Electronic Chart Navigation, for details of this process.

That is the way it works, and it is certainly no harder, if not easier, to learn MHW from an ENC than it is from an RNC.

The nuance to this process comes about because the ENC uses only one value of height datum (MHW) for the full range of the chart. This is not an issue for larger scale charts covering smaller regions as then the MHW does not vary much, but on small scale charts, even just at 1:80,000 we can have MWH from one part to another vary by as much as 3 feet. When this occurs, NOAA chooses just one value to represent all values on the chart, and that one value is chosen with safety in mind, which I emphasize as that is the topic at hand.
_________

Here is an example from the same region referred to in the Tidal Information table above that was captured from an RNC near Port Townsend, WA. First we look at two ENC chart scales, then the MHW on each.

We see that on a large scale chart, the ENC values change very little over the chart and the single value selected is a good representation of the actual values that we can read in the RNC table above. Oak Bay value is on the south side of the channel; the Port Townsend value is on the north side of the channel.

When we look at this same area on a much smaller chart scale, we now see that the ENC has chosen to use 10.5 ft to represent MHW on all areas on this chart, which does indeed span a much wider range of MHW values.

The question at hand is what does "safety in mind" mean in this choice.  If we have a range of MHW values, would the safest choice be the lowest of all of them, or the highest of all of them, or the average of the known values?

Bridge Clearance.
Bridge clearance is maybe the most direct example. As I approach a bridge to pass under and my mast is right near the max that might get through, I know that I count on favorable tide to help me, so I have to reckon the clearance I have.  The charted bridge clearance is 58 ft, which means that when the tide height equals MHW then the distance from water to bridge is 58 ft. When the tide is lower than MHW I have more clearance.

Actual clearance = charted clearance + (MHW - Tide).  When the Tide is exactly MHW,  then I get the charted clearance,  and when the Tide is lower than MHW I get extra clearance, but if the Tide is higher than MHW there is less actual clearance than charted.  With a MHW of 8 ft and a Tide of 3 ft, I would expect a clearance of 58 + 8 - 3 = 63 ft.

If this computation is to be wrong because the MHW value is wrong, most would agree you would want the clearance to err in the direction of predicting too little clearance, not too much clearance. If it erred being too big, I might try to go though and not make it. If the err makes it too low, I would not try…..or at least I would sneak up on it dead slow, hoping the tide itself was wrong and might sneak under. So with regard to bridge clearances, if my MHW is to be wrong, it is safest to have it be too small, meaning if we have a range of them over a specific ENC, but we can only choose one to use, the safest would be to use the smallest for all parts of the chart.

Geographic range of lights.
In clear weather, the visible range of a light is the smaller of the charted nominal range of the light and its geographic range in nmi, which is 1.17 x SQRT (Height of the Light in feet) plus a fixed term based on your height of eye.  The Height of the Light is given on the chart or in the Light List. These tabulated heights are all relative to MHW, which is the height datum of the charts. Thus a light with tabulated height of 20 ft would be that high above the water when the tide equals MHW. If the tide is less than MHW then the light is higher above the same water we are floating in, so we can see it from farther away.

Similar to the bridge clearance, actual Light height above the water = Tabulated height + (MHW - Tide). So then what is "safest" or most conservative if the MHW is to be off a bit? Do we want it too big, which would make the light higher than correct and thus visible from slightly farther than the truth, or do we want the visible range slightly under estimated with a low end MHW?  In other words, if the actual visible range to a light is 8 nmi, am I safer thinking it is 7 nmi or 9 nmi if it has to be one or the other.

My thought would be that it is safer to have the smaller range when planning an approach at night, and then when I see it earlier I know what to do, whereas if I think I should see it 9 nmi and do not, then I am not sure what is wrong with my navigation. So again in this case, the "safer" way to error on MHW is to take the lower limit.

Visibility of rocks.
On paper charts we have 3 kinds of rock symbols: a "plus-sign rock," which is a rock that is underwater for all tide heights greater than 0; an "asterisk rock,"  which is one that covers and uncovers when the tide is in the range of 0 to MHW (the height datum); and a "plus sign with 4 dots rock" that is awash when the tide is exactly or very near 0.

ENC has one rock object called UWTROC (Underwater/awash rock), which has an attribute WATLEV (Water level effect), which in turn can have values:

1. partly submerged at high water: partially covered and partially dry at high water.

2. always dry: not covered at high water under average meteorological conditions. [ This is an islet, not a rock. ]

3. always under water/submerged: remains covered by water at all times under average meteorological conditions. [ This is analogous to plus-sign rock. ]

4. covers and uncovers: expression intended to indicate an area of a reef or other projection from the bottom of a body of water which periodically extends above and is submerged below the surface. Also referred to as dries or uncovers. (IHO Dictionary, S-32, 5th Edition, 1111). [ This is analogous to the asterisk rock. ]

5. awash: flush with, or washed by the waves at low water under average meteorological conditions. (adapted from IHO Dictionary, S-32, 5th Edition, 308) [ This is the plus-sign with 4 dots rock. ]

6. subject to inundation or flooding: an area periodically covered by flood water, excluding tidal waters. (Digital Geographic Information Standard - DIGEST 1.2)

7. floating: Resting or moving on the surface of a liquid without sinking (Concise oxford Dictionary)

Here we confront several distinctions between RNC rocks and ENC rocks. First a simple terminology distinction. Paper charts refer to rocks awash as those that cover and uncover as the tide changes from the sounding datum (0 tide) to the height datum (MHW). We can confirm that in the IHO document S-4, where this K11 rock is listed as B-421.2.  This rock has a symbol of a simple asterisk on both RNC and ENC. On ENC it has a WATLEV = 4.

Here is the Bowditch definition, which is consistent with IHO S-4:

rock awash. A rock that becomes exposed, or nearly so, between chart sounding datum and mean high water.

In contrast, S-57 defines "rock awash" as one that is awash at or near the sounding datum, tide height = 0.  The ENC uses an asterisk for this rock as well, but assigns a WATLEV = 4.  Note that we must know the ENC definition of "awash" when reading this cursor pick.

The other distinction, which has effect on the present discussion, is the S-57 ENC definition of WATLEV 4, which is covers and uncovers—without any reference at all to the height datum, MHW. The quick conclusion from that is, the ENC choice of MHW therefore cannot have any influence on rock navigation, safe or unsafe, be it too high or too low. We could end it there, but for at least four more years we will navigate with both ENC and RNC, so we should still have a look at the consequences of an ENC error in MHW.

Right now if we have a rock that dries at 6 ft, with an actual MHW of 6 ft in that area, then this rock would be awash at tide = 6 ft, and for any tide height lower than this we would expect to see that rock.  If  the ENC reported MHW were 4 ft, then we would expect this asterisk symbol rock to be underwater or just at the surface at tide = 4 ft, but in fact when we got there it would be 2 ft above the surface. On the other hand, if the ENC reported the MHW at 8 ft, then we would expect to see this rock for any tide height less than 8 ft, but if we got there at tide 7 ft we would not see the rock.

In summary, if the above arguments are correct, then it seems that given a range of MHW values from which just one must be selected to encode into an ENC, then the "safest" value would be to choose the lowest one on the chart.

It seems to me that in at least some ENC this is not the guideline being used; it seems the higher end of the range is chosen.  So now I need to reach out to the professionals to learn more of the policy on this detail, and when I learn more, I will return here to correct the above as needed and fill in the rest of the answer.
___________

Note that although MHW is not directly included in NOAA Tide tables, there are two other parameters given for each station from which we can compute MHW:

Mean Range = MR = MHW - MLW

Mean Tide = MT = (MHW + MLW)/2, which, in passing,  is a good approximation to MSL

Thus we can rearrange these terms to solve for MHW = MT + MR/2

In Port Townsend, for example, MR = 5.34 and MT = 5.17, so MHW = 5.17 + 5.34/2 = 7.84

___________

## Wednesday, August 5, 2020

### Correcting Add East—An Overview of Compass Conversions

A true direction is the bearing of a target from your location measured relative to true north (000 T). True north is the direction on the horizon that is directly below the pole of the sky that all stars rotate about. It is the direction from any point on earth toward the North Pole, the one point on earth that is at latitude 90º exactly. Standing at this point, the true pole of the sky is overhead and every direction from there is south! True north is always placed at the top of standard nautical charts, which are made on a Mercator projection. Due east true is on the right side; due south on the bottom; and due west on the left side.

(Note that true north is not the direction to the North Star, Polaris. Polaris is overhead on latitude 89º 20' N, so it is about 40 nmi south of the true pole at any time. This makes its actual bearing vary from about 359 T to 001T depending on the date and time of night.)

A magnetic direction is the direction of a target from your location relative to a special direction  called "magnetic north" at your location. This direction is not unique, like true north is, but instead varies continuously across the surface of the earth. It is the direction of the strongest horizontal component of the magnetic field at the earth's surface. In short, it is the direction that any compass needle would point at that location.

Also unlike true north, magnetic north is not the direction to any specific point on earth. If we take a simple hiker's compass and look at the needle, it is aligning with the earth's magnetic force lines at this location, pointing to our local value of magnetic north.

(Note that magnetic north is specifically not pointing to the geomagnetic north pole of the earth; nor is it pointing to the magnetic north pole, which is actually a completely different concept, which we leave for now to the Wikipedia. When most of us say magnetic north pole, we actually mean geomagnetic north pole—as Trump says when he learns something for the first time "Not many people know that."

Since mariners rely on compass bearings to find their way across a chart, we must know for each point on earth what the difference is between magnetic north and true north.  Then we can read a magnetic direction from the compass and correct it to get the true direction that we can plot on the chart relative to the top or sides of the sheet.

The difference between true north and magnetic north is called variation or magnetic variation. Its ENC object name is MAGVAR. Magnetic variation is a well known number for all points on earth, but there are rare isolated regions, usually small, of anomalous values.

The numerical value of the variation varies from 0º to about 25º for most navigable waters below latitude 70º N. Variation is labeled East if magnetic north is to the east of true north. For example, if magnetic north is located at a direction of 016T, then this is to the east of true north at 000T so this would be var = 16 E, which is typical of the Pacific Northwest. In Northeast US waters, on the other hand, magnetic north is in the direction of about 348 T, which is 12º west of 000T, so this is var = 12º W.

To see how this works with variation of 16º E, if we are told that a target is at bearing 050 Magnetic, we know that means it is located 50º to the right of 000 Magnetic,  the direction of the local magnetic north. We know from the variation that magnetic north is 16º to the east of true north (000T), so this bearing of 050 M is pointing in the direction 050 + 16 = 066T. In short, regardless of the bearing around the compass card, the way to get true bearing from magnetic bearing will always be:

True direction = Magnetic direction + Variation East.

When the variation is west, we subtract it from the magnetic bearing to get true bearing.  These rules are summarized below.

compass direction is the bearing of a target (or the bow of the boat) from your location read directly from a compass. These are bearings relative to 000 on the compass card. Ideally this would be identical to the magnetic direction, which is afterall defined as the direction a compass needle would point. But that is assuming the needle is feeling just the earth's magnetic field. We assume the compass is not being disturbed by any external magnetic fields.

If you have a compass sitting in a clean position, not near any magnetic materials, then 000 on the card will point in the direction of the earth's magnetic field, and indeed bearings read from this compass will be the same as magnetic bearings.  But set a magnetic screwdriver near that compass and you will see the needle move to a new direction, which is not the correct magnetic direction.

The difference between magnetic north and compass north at any time, on any vessel heading, is called the deviation of that compass on that heading. Deviation is labeled E if the compass bearing is east of the correct magnet bearing. Thus if a compass bearing is 050 C when the correct magnetic bearing is 045 M, then this deviation is 5º E. The conversion is the same as with variation:

Magnetic direction = Compass direction + Deviation East.

When the deviation is west, we subtract it from the compass bearing to get magnetic bearing.  These rules are summarized below.

Here are the rules

CORRECTING

UNCORRECTING

Maritime training has traditionally called going from Magnetic to True or going from Compass to Magnetic as "correcting" and going the other way as "uncorrecting." Neither are very tidy terms, but we feel it is best to not generate new terminology in this arena.

On the other hand, individual mariners are welcome to create whatever rules work for them.

I have always used the one rule "correcting add east." From this I understand that "uncorrecting" would call for adding west, and if the variation or deviation is west and not east, then the adding goes to subtracting—but I do not say this in my mind or on paper.  One short rule goes into the mind: "correcting add east"—then if anything changes, the add goes to subtract.

With all that said, on a long trip where you are likely to be tired when navigating and the local variation is say 17º E, it pays to just write somewhere prominent in the nav station that
TRUE = MAGNETIC + 17º
MAGNETIC = TRUE – 17º
Then you are less likely to make a mistake when tired, and others at the nav station can see this to keep it in mind as well. This is especially true on a long trip that covers new waters for you, where you will not know the variation by heart. This saves looking it up every time you need it. Then just update your note as the variation changes. We learned this trick well on a trip from Long Island Sound, NY to San Juan Islands, WA down through the Canal.

If you have failed to do that and end up really tired and maybe a bit seasick on top of that, and the conditions are terrible and it is hard to think, then just look at a compass rose and draw a line across it to get the conversion done for you.

Doing a compass conversion with the compass rose for variation 17ºE

We tend to concentrate on variation, but the deviation is handled the same way. On a non-steel boat we should be able to adjust all of the deviation out of our compasses.  Below we work a generic example with both variation and deviation.

As a minor point with regard to these conversions, in our course we do not use the term "compass error." The official US maritime definition (Bowditch, Dutton, etc, and see Note 1 below) of "compass error" is the algebraic sum of the deviation and variation. To me this is a muddy concept, which is to be avoided. First and foremost, variation is not an error in any sense. It is the deviation alone that is an error.

Secondly, it combines two completely different effects. Variation is a well-defined physical property of the planet earth at that location and date that applies to all compasses, everywhere on the vessel. We can look variation up very easily from numerous sources beside the chart, including phone apps.

Deviation, on the other hand, is a totally nebulous quantity, difficult to measure, unique to a specific compass, different on every vessel heading, and likely to change over a single long voyage. In short, we recommend keeping these two concepts completely separated and not to ever combine them into a single "compass error."

One way to remember the terms if you are new to the subject is to ponder the thought that "God makes Variation; Man makes Deviation."

We propose trying the one simple rule (correcting add east) for all conversions, which I will illustrate in a moment, but many mariners have found a form solution useful. They typically look like:

True           ___________
var              ___________
Magnetic    ___________
dev             ___________
Compass    ___________

You put in what you know and go up or down the form to find the missing values. In this form the var and the dev will have labels E or W. Going up this form is correcting, going down is uncorrecting.

Here is another more practical form of the form

In other words, "going up" is finding Magnetic from Compass so Dev E is +, and finding True from  Magnetic so Var E is +

The jingle used is Can Dead Men Vote Twice... at elections, which reminds of the correcting sequence with "at elections" reminding us to add east when correcting.

Here is a set of practice exercises from our Navigation Workbook: 18465Tr

This is 9 practice exercises in carrying out various compass conversions. In an extended career in navigation, you might actually run across any one of these, although it is more rare on non-steel boats. Again, on non-steel boats, we should be able to make all compasses free of deviation, but that does not mean they will stay that way.  A lightning strike, for example, is a rare event that can indeed disturb the compasses, as can loading the vessel in new ways, or installing equipment without thinking about the compasses.

In modern times, we tend to have a lot of compasses (electronic and magnetic), and it is rare to have them all agree, so we have to then track down which ones have deviation and what it is, and generally to do that we have to have complete control over these types of conversions.

Example (A) is pretty basic. We are at sea at a known Lat-Lon, time, and date and we want to check our compass for deviation. We point the vessel to a star and the compass reads 296 C. For this time and place, we then use celestial navigation to compute the true bearing to that star, which is 280 T. We know from our chart or software that the variation at this location is 16ºW. So what is our deviation?

Dev is the difference between compass and magnetic, so we have to compute the magnetic from known true and variation. This is called uncorrecting and the rule is uncorrecting add west, so magnetic is 280T + 16W = 296 M, which is the same as compass, so the deviation is 0.

Example (B) would be the case where I was told that the proper course to stay on the entrance range is 014 M, so i need the compass course to steer, knowing the compass has a deviation of 5E on that magnetic heading, and I want to check this information on the chart, but the only chart I have does not have a magnetic compass rose, so i need the true heading as well, in an area where the variation is 21E.

We want True from known Magnetic and var, so this is just correcting add east, or  T = 014M +21E = 035T. Getting the Compass from known Magnetic and dev is uncorrecting, so C = 014M -5E = 009C.

Example (C) We want to find the local variation, because we do not have a chart with it, nor the software to compute it. We point the boat toward an object we know the true bearing to (ie 007 T), which we could get from a chart in coastal waters or at sea from a cel nav computation.

We read our compass heading and we know the dev at this heading, so we can find the Magnetic heading by correcting 354C - 8W = 346M. The rule is correcting add east, but this one is west, so we subtract.

So now we know True = 007 and Magnetic is 346 M, and we know the difference is the var, which is 346 to 360, which is 14º and then on around by 7º more, so the total difference between Magnetic and True is 21º.  Then we choose the label of the variation by noting that 346 + 21 = 007, so since it is plus in the correcting direction it must be East. Ans 21E.

Since this one more involved, let's see if the form helps:

True    007
var      ___
Mag    ___
dev      8W
Comp  354

We get Magnetic going up, which is correcting, which is add east, subtract west, so we now have

True    007
var      ___
Mag    346
dev      8W
Comp  354

And we are back to figuring the difference between Magnetic and True as before, which we know is 21º, so the form now looks like

True    007
var       21 .... now is this E or W?
Mag    346
dev      8 W
Comp  354

And at this point, form or no form, we have to reason through the label E or W.  Thinking in terms of correcting, we have 346 ± 21 = 007.  This has to be +, so the label has to be E, based on the the rule "correcting add east."

In summary, we have to ask ourselves if a form helps with these conversions or can we do variation corrections and the deviation corrections independently and then combine these results when needed.

The question is, does the form help, or can we do it with just "correcting add east" and then knowing what we mean by correcting.

Here are the answers for more practice.

A related article: Compass Bearing Fix: An Overview

Note 1.  We have yet to find an "official" British Admiralty definition (The Admiralty Manual of Navigation, Vol 1 does not use the term "compass error."), but in the British book Self Instruction in the Practice and Theory of Navigation, Vol. 1 by the Earl of Dunraven (London, 1900) on page 66 he states: "Error is caused by Variation or by Deviation, or by both combined. We shall consider the effect of Error from whatever causes it to arise."

## Thursday, July 30, 2020

### US Weather Map File Names

Starpath Weather Map Files Names

# US Weather Map File Names

This compilation is adapted from the Starpath Weather Trainer The files are located at https://tgftp.nws.noaa.gov/fax.
 To request files by email via NWS FTPmail via Saildocs To: NWS.FTPMail.OPS@noaa.gov Subject line can be anything Body should read (sample request for 2 maps): open cd fax get PWBE10.TIF get PWBM99.TIF quit To: query@saildocs.com Subject line can be anything Body should read (sample request for 2 maps): send PWBE10.TIF send PWBM99.TIF This can get the files reduced by 50% in size. Works for many, but not all files.
Atlantic
WIND/SEAS CHARTS
SURFACE CHARTS
UPPER AIR CHARTS
TROPICAL CYCLONE CHARTS
SATELLITE IMAGERY
ICE CHARTS
SCHEDULE INFORMATION
Gulf
WIND/WAVE CHARTS
SURFACE CHARTS
TROPICAL CYCLONE CHARTS
HIGH SEAS FORECASTS
SATELLITE IMAGERY
SCHEDULE INFORMATION
Pacific
WIND/WAVE CHARTS
TROPICAL WIND/WAVE CHARTS
SURFACE CHARTS
TROPICAL SURFACE CHARTS
UPPER AIR CHARTS
TROPICAL CYCLONE CHARTS
SEA SURFACE TEMPERATURES
SATELLITE IMAGERY
SCHEDULE INFORMATION
WIND/WAVE CHARTS
SURFACE CHARTS
UPPER AIR CHARTS
SEA SURFACE TEMPERATURES
SATELLITE IMAGERY
ICE CHARTS
SCHEDULE INFORMATION and MISCELLANEOUS
Hawaii
WIND/WAVE CHARTS - CENTRAL PACIFIC
WIND/WAVE CHARTS - SE PACIFIC
WIND/WAVE CHARTS - NORTH PACIFIC
SURFACE CHARTS - CENTRAL PACIFIC
SURFACE CHARTS - SE PACIFIC
SURFACE CHARTS - NORTH PACIFIC
TROPICAL CYCLONE CHARTS - PACIFIC
SEA SURFACE TEMPERATURE CHARTS
SATELLITE IMAGERY (IR)
SCHEDULE INFORMATION

 Atlantic Maps WIND/SEAS CHARTS NAME 12Z Sea State Analysis, 10E-95W Northern Hemisphere PJAA99.TIF 00Z Wind/Wave Analysis, 40W-98W Northern Hemisphere PWAA88.TIF 06Z Wind/Wave Analysis, 40W-98W Northern Hemisphere PWAB88.TIF 12Z Wind/Wave Analysis, 40W-98W Northern Hemisphere PWAA89.TIF 18Z Wind/Wave Analysis, 40W-98W Northern Hemisphere PWAD89.TIF Wind/Wave Analysis, (Most Current) PWAA90.TIF 24HR Wind/Wave Chart VT00Z Forecast 40W-98W N. Hemisphere PWAE98.TIF 24HR Wind/Wave Chart VT12Z Forecast 40W-98W N. Hemisphere PWAE99.TIF 24HR Wind/Wave Chart Forecast (Most Current) PWAE10.TIF 48HR Wind/Wave VT00Z Forecast 10E-95W Northern Hemisphere PJAI98.TIF 48HR Wind/Wave VT12Z Forecast 10E-95W Northern Hemisphere PJAI99.TIF 48HR Wind/Wave Chart Forecast (Most Current) PJAI10.TIF 48HR Wave Period VT00Z Forecast 10E-95W Northern Hemisphere PJAI88.TIF 48HR Wave Period VT12Z Forecast 10E-95W Northern Hemisphere PJAI89.TIF 48HR Wave Period Chart Forecast (Most Current) PJAI20.TIF 72HR 12Z North Atlantic 72 hour Wind/Wave Forecast PJAK88.TIF 96HR Wind/Wave Chart VT12Z Forecast 10E-95W N. Hemisphere PJAM98.TIF 96HR Wave Period VT12Z Forecast 10E-95W N. Hemisphere PJAM88.TIF SURFACE CHARTS 00Z Preliminary Surface Chart Analysis 45W-85W N. Hemisphere PYAA10.TIF 06Z Preliminary Surface Chart Analysis 45W-85W N. Hemisphere PYAB01.TIF 12Z Preliminary Surface Chart Analysis 45W-85W N. Hemisphere PYAC01.TIF 18Z Preliminary Surface Chart Analysis 45W-85W N. Hemisphere PYAD01.TIF Preliminary Surface Chart Analysis (Most Current) PYAD10.TIF 00Z Surface Analysis Chart, Part 1, 10E-45W N. Hemisphere PYAA01.TIF 00Z Surface Analysis Chart, Part 2, 40W-95W N. Hemisphere PYAA02.TIF 06Z Surface Analysis Chart, Part 1, 10E-45W N. Hemisphere PYAA03.TIF 06Z Surface Analysis Chart, Part 2, 40W-95W N. Hemisphere PYAA04.TIF 12Z Surface Analysis Chart, Part 1, 10E-45W N. Hemisphere PYAA05.TIF 12Z Surface Analysis Chart, Part 2, 40W-95W N. Hemisphere PYAA06.TIF 18Z Surface Analysis Chart, Part 1, 10E-45W N. Hemisphere PYAA07.TIF 18Z Surface Analysis Chart, Part 2, 40W-95W N. Hemisphere PYAA08.TIF Surface Analysis Chart, Part 1, (Most Current) PYAA11.TIF Surface Analysis Chart, Part 2, (Most Current) PYAA12.TIF 24HR Surface Chart VT00Z Forecast 40W-98W Northern Hemisphere PPAE00.TIF 24HR Surface Chart VT12Z Forecast 40W-98W Northern Hemisphere PPAE01.TIF 24HR Surface Chart Forecast (Most Current) PPAE10.TIF 48HR Surface Chart VT00Z Forecast 10E-95W Northern Hemisphere QDTM85.TIF 48HR Surface Chart VT12Z Forecast 10E-95W Northern Hemisphere QDTM86.TIF 48HR Surface Chart Forecast (Most Current) QDTM10.TIF 72HR 12Z North Atlantic 72 hour Surface Forecast PPAK98.TIF 96HR Surface Chart VT12Z Forecast 10E-96W Northern Hemisphere PWAM99.TIF UPPER AIR CHARTS 00Z 500MB Surface Chart Analysis 10E-95W Northern Hemisphere PPAA50.TIF 12Z 500MB Surface Chart Analysis 10E-95W Northern Hemisphere PPAA51.TIF 500MB Surface Chart Analysis (Most Current) PPAA10.TIF 24HR 500MB Chart VT00Z Forecast 10E-95W Northern Hemisphere PPAE50.TIF 24HR 500MB Chart VT12Z Forecast 10E-95W Northern Hemisphere PPAE51.TIF 24HR 500MB Chart Forecast (Most Current) PPAE11.TIF 36HR 500MB Chart VT00Z Forecast 10E-95W Northern Hemisphere PPAG51.TIF 36HR 500MB Chart VT12Z Forecast 10E-95W Northern Hemisphere PPAG50.TIF 36HR 500MB Chart Forecast (Most Current) PPAG11.TIF 48HR 500MB Chart VT00Z Forecast 10E-95W Northern Hemisphere PPAI50.TIF 48HR 500MB Chart VT12Z Forecast 10E-95W Northern Hemisphere PPAI51.TIF 48HR 500MB Chart Forecast (Most Current) PPAI10.TIF 96HR 500MB Chart VT12Z Forecast 10E-95W Northern Hemisphere PPAM50.TIF TROPICAL CYCLONE CHARTS Tropical Cyclone Danger Area* VT03, 05N-60N, 00W-100W PWEK89.TIF Tropical Cyclone Danger Area* VT09, 05N-60N, 00W-100W PWEK90.TIF Tropical Cyclone Danger Area* VT15, 05N-60N, 00W-100W PWEK91.TIF Tropical Cyclone Danger Area* VT21, 05N-60N, 00W-100W PWEK88.TIF Tropical Cyclone Danger Area* (Most Current) PWEK11.TIF SATELLITE IMAGERY 00Z GOES IR Satellite Image, West Atlantic evnt00.jpg 06Z GOES IR Satellite Image, Atlantic evnt06.jpg 12Z GOES IR Satellite Image, West Atlantic evnt12.jpg 18Z GOES IR Satellite Image, Atlantic evnt18.jpg W Atlantic or Atlantic (Most Current) evnt99.jpg ICE CHARTS Ice Chart from U.S. Coast Guard International Ice Patrol PIEA88.TIF (During Ice Season only ~Feb-Sep, for further information see: http://www.uscg.mil/lantarea/iip/home.html) SCHEDULE INFORMATION Radiofax Schedule Part 1 (Boston, MA) PLAZ01.TIF Radiofax Schedule Part 2 (Boston, MA) PLAZ02.TIF Radiofax Schedule (DOS Text Version) hfmarsh.txt Request for Comments PLAZ03.TIF Product Notice Bulletin PLAZ04.TIF Test Pattern PZZZ94.TIF Internet File Names (This file) rfaxatl.txt

 Gulf Maps WIND/WAVE CHARTS NAME 00Z Sea State Analysis, 0N-31N, 35W-100W PJEA88.TIF 12Z Sea State Analysis, 0N-31N, 35W-100W PJEA90.TIF Sea State Analysis (Most Current) PJEA11.TIF 24HR Wind/Wave Forecast VT00, 0N-31N, 35W-100W PWEE89.TIF 24HR Wind/Wave Forecast VT12, 0N-31N, 35W-100W PWEE91.TIF 24HR Wind/Wave Forecast (Most Current) PWEE11.TIF 36HR Wind/Wave Forecast VT12, 0N-31N, 35W-100W PWED98.TIF 48HR Wind/Wave Forecast VT00, 0N-31N, 35W-100W PWEI88.TIF 48HR Wind/Wave Forecast VT12, 0N-31N, 35W-100W PWEI89.TIF 48HR Wind/Wave Forecast (Most Current) PWEI11.TIF 48HR Wave Period/Swell Dir Forecast VT00, 0N-31N, 35W-100W PJEI88.TIF 48HR Wave Period/Swell Dir Forecast VT12, 0N-31N, 35W-100W PJEI89.TIF 48HR Wave Period/Swell Direction Forecast (Most Current) PJEI11.TIF 72HR Wind/Wave Forecast VT00, 0N-31N, 35W-100W PJEK88.TIF 72HR Wind/Wave Forecast VT12, 0N-31N, 35W-100W PJEK89.TIF 72HR Wind/Wave Forecast (Most Current) PJEK11.TIF 72HR Wave Period/Swell Dir Forecast VT00, 0N-31N, 35W-100W PKEK88.TIF SURFACE CHARTS *00Z U.S./Tropical Surface Analysis (W Half) 5S-50N,55W-125W PYEB86.TIF *06Z U.S./Tropical Surface Analysis (W Half) 5S-50N,55W-125W PYEB87.TIF *12Z U.S./Tropical Surface Analysis (W Half) 5S-50N,55W-125W PYEB85.TIF *18Z U.S./Tropical Surface Analysis (W Half) 5S-50N,55W-125W PYEB88.TIF * U.S./Tropical Surface Analysis (W Half) (Most Current) PYEB11.TIF 00Z Tropical Surface Analysis (E Half) 5S-50N, 0W-70W PYEA86.TIF 06Z Tropical Surface Analysis (E Half) 5S-50N, 0W-70W PYEA87.TIF 12Z Tropical Surface Analysis (E Half) 5S-50N, 0W-70W PYEA85.TIF 18Z Tropical Surface Analysis (E Half) 5S-50N, 0W-70W PYEA88.TIF Tropical Surface Analysis (E Half) (Most Current) PYEA11.TIF 24HR Tropical Surface Forecast(E Half)VT00,00N-31N, 35W-100W PYEE79.TIF 24HR Tropical Surface Forecast(E Half)VT12,00N-31N, 35W-100W PYEE80.TIF Tropical Surface Forecast(Most Current) PYEE10.TIF 48HR Tropical Surface Forecast(E Half)VT00,00N-31N, 35W-100W PYEI81.TIF 48HR Tropical Surface Forecast(E Half)VT12,00N-31N, 35W-100W PYEI82.TIF Tropical Surface Forecast(Most Current) PYEI10.TIF 72HR Tropical Surface Forecast(E Half)VT00,00N-31N, 35W-100W PYEK83.TIF 72HR Tropical Surface Forecast(E Half)VT12,00N-31N, 35W-100W PYEK84.TIF Tropical Surface Forecast(Most Current) PYEK10.TIF * For further forecasts covering the Tropical East Pacific, see Pt. Reyes and Honolulu charts TROPICAL CYCLONE CHARTS Tropical Cyclone Danger Area* VT03, 05N-60N, 00W-100W PWEK89.TIF Tropical Cyclone Danger Area* VT09, 05N-60N, 00W-100W PWEK90.TIF Tropical Cyclone Danger Area* VT15, 05N-60N, 00W-100W PWEK91.TIF Tropical Cyclone Danger Area* VT21, 05N-60N, 00W-100W PWEK88.TIF Tropical Cyclone Danger Area* (Most Current) PWEK11.TIF HIGH SEAS FORECASTS 04Z High Seas Forecast 7N-31N, 35W-98W, In English PLEA86.TIF 10Z High Seas Forecast 7N-31N, 35W-98W, In English PLEA87.TIF 16Z High Seas Forecast 7N-31N, 35W-98W, In English PLEA89.TIF 22Z High Seas Forecast 7N-31N, 35W-98W, In English PLEA88.TIF High Seas Forecast (Most Current) PLEA10.TIF SATELLITE IMAGERY 0645Z GOES IR Satellite Image, 12S-44N, 28W-112W evst06.jpg 1145Z GOES IR Satellite Image, 12S-44N, 28W-112W evst12.jpg 1745Z GOES IR Satellite Image, 12S-44N, 28W-112W evst18.jpg 2345Z GOES IR Satellite Image, 12S-44N, 28W-112W evst00.jpg GOES IR Satellite Image (Most Current) evst99.jpg SCHEDULE INFORMATION Radiofax Schedule (New Orleans, LA) PLEZ01.TIF Radiofax Schedule (DOS Text Format) hfgulf.txt Request for Comments PLEZ02.TIF Product Notice Bulletin PLEZ03.TIF Test Chart PZZZ95.TIF Internet File Names, (This file) rfaxmex.txt

 Pacific Maps WIND/WAVE CHARTS NAME 00Z Sea State Analysis 20N-70N, 115W-135E PJBA99.TIF **00Z Wind/Wave Analysis 18N-62N, E OF 157W PWBA88.TIF 06Z Wind/Wave Analysis 18N-62N, E OF 157W PWBB88.TIF 12Z Wind/Wave Analysis 18N-62N, E OF 157W PWBA89.TIF 18Z Wind/Wave Analysis 18N-62N, E OF 157W PWBD89.TIF Wind/Wave Analysis 18N-62N, E OF 157W (Most Current) PWBA90.TIF 24HR Wind/Wave Forecast VT00Z 18N-62N, E of 157W PWBE98.TIF 24HR Wind/Wave Forecast VT12Z 18N-62N, E of 157W PWBE99.TIF 24HR Wind/Wave Forecast (Most Current) PWBE10.TIF 48HR Wind/Wave Forecast VT00Z 20N-70N, 115W-135E PJBI98.TIF 48HR Wind/Wave Forecast VT12Z 20N-70N, 115W-135E PJBI99.TIF 48HR Wind Wave Forecast (Most Current) PJBI10.TIF 48HR Wave Period/Swell Direction VT00Z 20N-70N, 115W-135E PJBI88.TIF 48HR Wave Period/Swell Direction VT12Z 20N-70N, 115W-135E PJBI89.TIF 48HR Wave Period/Swell Direction (Most Current) PJBI20.TIF 72HR 12Z North Pacific 72 hour Wind/Wave Forecast PJBK88.TIF 96HR Wind/Wave Forecast VT12Z 20N-70N, 115W-135E PJBM98.TIF 96HR Wave Period/Swell Direction VT12Z 20N-70N, 115W-135E PJBM88.TIF TROPICAL WIND/WAVE CHARTS Tropical Sea State Analysis VT00Z 20S-30N, E of 145W PKFA88.TIF Tropical Sea State Analysis VT12Z 20S-30N, E of 145W PKFA89.TIF Tropical Sea State Analysis (Most Current) PKFA10.TIF **24HR Wind/Wave Forecast VT00Z 20S-30N, E of 145W PWFE01.TIF **24HR Wind/Wave Forecast VT12Z 20S-30N, E of 145W PWFE03.TIF **24HR Wind/Wave Forecast (Most Current) PWFE10.TIF 48HR Wind/Wave Forecast VT00Z 20S-30N, E of 145W PWFI88.TIF 48HR Wind/Wave Forecast VT12Z 20S-30N, E of 145W PWFI90.TIF 48HR Wind/Wave Forecast (Most Current) PWFI10.TIF 48HR Wave Period/Swell Direction VT00Z 20S-30N,E of 145W PJFI87.TIF 48HR Wave Period/Swell Direction VT12Z 20S-30N, E of 145W PJFI88.TIF 48HR Wave Period/Swell Direction (Most Current) PJFI11.TIF 72HR Wind/Wave Forecast VT00Z 20S-30N, E of 145W PWFK92.TIF 72HR Wind/Wave Forecast VT12Z 20S-30N, E of 145W PWFK93.TIF 72HR Wind/Wave Forecast (Most Current) PWFK10.TIF 72HR Wave Period/Swell Direction VT00Z 20S-30N,E of 145W PJFK93.TIF SURFACE CHARTS 00Z Surface Analysis NE Pacific (Part 1) 20N-70W, 115W-175W PYBA01.TIF 00Z Surface Analysis NW Pacific (Part 2) 20N-70W, 175W-135E PYBA02.TIF 06Z Surface Analysis NE Pacific (Part 1) 20N-70W, 115W-175W PYBA03.TIF 06Z Surface Analysis NW Pacific (Part 2) 20N-70W, 175W-135E PYBA04.TIF 12Z Surface Analysis NE Pacific (Part 1) 20N-70W, 115W-175W PYBA05.TIF 12Z Surface Analysis NW Pacific (Part 2) 20N-70W, 175W-135E PYBA06.TIF 18Z Surface Analysis NE Pacific (Part 1) 20N-70W, 115W-175W PYBA07.TIF 18Z Surface Analysis NW Pacific (Part 2) 20N-70W, 175W-135E PYBA08.TIF Surface Analysis, Part 1 (Most Current) PYBA90.TIF Surface Analysis, Part 2 (Most Current) PYBA91.TIF 24HR Surface Forecast VT00Z Forecast 18N-62N, E of 157W PPBE00.TIF 24HR Surface Forecast VT12Z Forecast 18N-62N, E of 157W PPBE01.TIF 24HR Surface Forecast (Most Current) PPBE10.TIF 48HR Surface Forecast VT00Z 20N-70W, 115W-135E PWBI98.TIF 48HR Surface Forecast VT12Z 20N-70W, 115W-135E PWBI99.TIF 48HR Surface Forecast (Most Current) PWBI10.TIF 72HR 12Z North Pacific 72 hour Surface Forecast PPBK98.TIF 96HR Surface Forecast VT12Z 20N-70W, 115W-135E PWBM99.TIF TROPICAL SURFACE CHARTS 00Z East Pacific Surface Analysis 20S-30N, E of 145W PYFA96.TIF 06Z East Pacific Surface Analysis 20S-30N, E of 145W PYFA97.TIF 12Z East Pacific Surface Analysis 20S-30N, E of 145W PYFA98.TIF 18Z East Pacific Surface Analysis 20S-30N, E of 145W PYFA99.TIF East Pacific Surface Analysis (Most Current) PYFA90.TIF **00Z U.S./Tropical Surface Analysis 5S-50N,55W-125W PYEB86.TIF **06Z U.S./Tropical Surface Analysis 5S-50N,55W-125W PYEB87.TIF **12Z U.S./Tropical Surface Analysis 5S-50N,55W-125W PYEB85.TIF **18Z U.S./Tropical Surface Analysis 5S-50N,55W-125W PYEB88.TIF ** U.S./Tropical Surface Analysis (Most Current) PYEB11.TIF **24HR Tropical Surface Forecast VT00Z 20S-30N,80W-145W PYFE79.TIF **24HR Tropical Surface Forecast VT12Z 20S-30N,80W-145W PYFE80.TIF **24HR Tropical Surface Forecast (Most Current); PYFE10.TIF 48HR Tropical Surface Forecast VT00Z 20S-30N,80W-145W PYFI81.TIF 48HR Tropical Surface Forecast VT12Z 20S-30N,80W-145W PYFI82.TIF 48HR Tropical Surface Forecast (Most Current); PYFI10.TIF **72HR Tropical Surface Forecast VT00Z 20S-30N,80W-145W PYFK83.TIF **72HR Tropical Surface Forecast VT12Z 20S-30N,80W-145W PYFK84.TIF **72HR Tropical Surface Forecast (Most Current); PYFK10.TIF UPPER AIR CHARTS 00Z 500 MB Analysis 20N-70N 115W-135E PPBA50.TIF 12Z 500 MB Analysis 20N-70N, 115W-135E PBBA51.TIF 500 MB Analysis (Most Current) PPBA10.TIF 24HR 500 MB Forecast VT00Z 20N-70N, 115W-135E PPBE50.TIF 24HR 500 MB Forecast VT12Z 20N-70N, 115W-135E PPBE51.TIF 24HR 500 MB Forecast (Most Current) PPBE11.TIF 48HR 500 MB Forecast VT00Z 20N-70N, 115W-135E PPBI50.TIF 48HR 500 MB Forecast VT12Z 20N-70N, 115W-135E PPBI51.TIF 48HR 500 MB Forecast (Most Current) PPBI10.TIF 96HR 500 MB VT12Z 20N-70N, 115W-135E PPBM50.TIF TROPICAL CYCLONE CHARTS 72 HR Tropical Cyclone Danger Area VT 03Z 0N-40N, 80W-180W PWFK88.TIF 72 HR Tropical Cyclone Danger Area VT 09Z 0N-40N, 80W-180W PWFK89.TIF 72 HR Tropical Cyclone Danger Area VT 15Z 0N-40N, 80W-180W PWFK90.TIF 72 HR Tropical Cyclone Danger Area VT 21Z 0N-40N, 80W-180W PWFK91.TIF 72 HR Tropical Cyclone Danger Area (Most Current) PWFK11.TIF Note: Tropical Cyclone Danger Area chart replaced by 48HR High Wind/Wave Warning chart Dec 01 - May 14 Valid times 00z,06z,12z and 18z SEA SURFACE TEMPERATURES Pacific SST Chart 40N-53N, E of 136W PTBA88.TIF Pacific SST Chart 23N-42N, E of 150W PTBA89.TIF SATELLITE IMAGERY **00Z GOES IR Satellite Image, Tropical East Pacific evpn02.jpg 06Z GOES IR Satellite Image, Tropical East Pacific evpn07.jpg **12Z GOES IR Satellite Image, Tropical East Pacific evpn04.jpg 18Z GOES IR Satellite Image, Tropical East Pacific evpn08.jpg GOES IR Satellite Image, Tropical East Pac (MOST CURRENT) evpn10.jpg **06Z GOES IR Satellite Image, East Pacific evpn03.jpg 12Z GOES IR Satellite Image, East Pacific evpn13.jpg **18Z GOES IR Satellite Image, East Pacific evpn14.jpg 21Z GOES VISIBLE Satellite Image, East Pacific evpn00.jpg GOES Satellite Image, East Pacific (MOST CURRENT) evpn98.jpg 00Z GOES IR Satellite Image, Pacific evpn01.jpg 06Z GOES IR Satellite Image, Pacific evpn06.jpg 12Z GOES IR Satellite Image, Pacific evpn12.jpg 18Z GOES IR Satellite Image, Pacific evpn18.jpg GOES IR Satellite Image, Pacific (MOST CURRENT) evpn99.jpg SCHEDULE INFORMATION Radiofax Schedule Part 1 (Point Reyes, CA) PLBZ01.TIF Radiofax Schedule Part 2 (Point Reyes, CA) PLBZ02.TIF Radiofax Schedule (DOS Text Format) hfreyes.txt Request for Comments PLBZ03.TIF Product Notice Bulletin PLBZ04.TIF Test Pattern PZZZ93.TIF Internet File Names (This file) rfaxpac.txt ** Not transmitted via Pt. Reyes radiofax but listed here for convenience

 Alaska Maps WIND/WAVE CHARTS NAME 00Z Sea State Analysis 20N-70N, 115W-135E PJBA99.TIF 24HR Wind/Wave Forecast VT00Z 40N-70N, 115W-170E PJBE88.TIF 24HR Wind/Wave Forecast VT12Z 40N-70N, 115W-170E PJBE89.TIF 24HR Wind Wave Forecast (Most Current) PJBE10.TIF 48HR Wind/Wave Forecast VT00Z 20N-70N, 115W-135E PJBI98.TIF 48HR Wind/Wave Forecast VT12Z 20N-70N, 115W-135E PJBI99.TIF 48HR Wind Wave Forecast (Most Current) PJBI10.TIF 48HR Wave Period/Swell Direction VT00Z 20N-70N, 115W-135E PJBI88.TIF 48HR Wave Period/Swell Direction VT12Z 20N-70N, 115W-135E PJBI89.TIF 48HR Wave Period/Swell Direction (Most Current) PJBI20.TIF 72HR 12Z Arctic/Alaska 72 hour Wind/Wave Forecast PJCK88.gif 96HR Wind/Wave Forecast VT12Z 20N-70N, 115W-135E PJBM98.TIF 96HR Wave Period/Swell Direction VT12Z 20N-70N, 115W-135E PJBM88.TIF SURFACE CHARTS 00Z Surface Analysis 40N-70N, 125W-150E PYCA00.TIF 06Z Surface Analysis 40N-70N, 125W-150E PYCA01.TIF 12Z Surface Analysis 40N-70N, 125W-150E PYCA02.TIF 18Z Surface Analysis 40N-70N, 125W-150E PYCA03.TIF Surface Analysis (Most Current) PYCA10.TIF 24HR Surface Chart Forecast VT00Z 40N-70N, 115W-170E PYBE00.TIF 24HR Surface Chart Forecast VT12Z 40N-70N, 115W-170E PYBE01.TIF 24HR Surface Chart Forecast (Most Current) PYBE10.TIF 48HR Surface Chart Forecast VT00Z 20N-70N 115W-135E PWBI98.TIF 48HR Surface Chart Forecast VT12Z 20N-70N 115W-135E PWBI99.TIF 48HR Surface Chart Forecast (Most Current) PWBI10.TIF 72HR 12Z Arctic/Alaska 72 hour Surface Forecast PPCK98.gif 96HR Surface Chart Forecast VT12Z PWBM99.TIF UPPER AIR CHARTS 00Z 500 MB Analysis 20N-70N 115W-135E PPBA50.TIF 12Z 500 MB Analysis 20N-70N, 115W-135E PBBA51.TIF 500 MB Analysis (Most Current) PPBA10.TIF 24HR 500 MB Forecast VT00Z 20N-70N, 115W-135E PPBE50.TIF 24HR 500 MB Forecast VT12Z 20N-70N, 115W-135E PPBE51.TIF 24HR 500 MB Forecast (Most Current) PPBE11.TIF 48HR 500 MB Forecast VT00Z 20N-70N, 115W-135E PPBI50.TIF 48HR 500 MB Forecast VT12Z 20N-70N, 115W-135E PPBI51.TIF 48HR 500 MB Forecast (Most Current) PPBI10.TIF 96HR 500 MB VT12Z 20N-70N, 115W-135E PPBM50.TIF SEA SURFACE TEMPERATURES Sea Surface Temperature Analysis 40N-60N,125W - 160E PTCA88.TIF SATELLITE IMAGERY 00Z GOES IR Satellite Image, Pacific evpn01.jpg 06Z GOES IR Satellite Image, Pacific evpn06.jpg 12Z GOES IR Satellite Image, Pacific evpn12.jpg 18Z GOES IR Satellite Image, Pacific evpn18.jpg GOES IR Satellite Image, Pacific (MOST CURRENT) evpn99.jpg ICE CHARTS Sea Ice Analysis PTCA89.TIF 5 Day Sea Ice Forecast PTCO89.TIF Cook Inlet Sea Ice Analysis PTCA87.TIF SCHEDULE INFORMATION and MISCELLANEOUS Radiofax Schedule Kodiak, AK; PLBZ05.TIF Radiofax Schedule (DOS Text Version) hfak.txt Request for Comments NOJCOMMENTS.TIF Product Notice Bulletin NOJNOTICE.TIF Test Pattern; NOJTEST.TIF Radiofacsimile Symbols and Contractions PLBZ06.TIF Internet File Names; (This file) rfaxak.txt

 Hawaii Maps WIND/WAVE CHARTS - CENTRAL PACIFIC NAME 00Z Pacific Wind/Wave Analysis 30S-30N, 110W-130E PJFB89.TIF 12Z Pacific Wind/Wave Analysis 30S-30N, 110W-130E PJFD89.TIF Pacific Wind/Wave Analysis (Most Current) PJFB10.TIF 24HR Pacific Wind/Wave Forecast VT00Z 30S-30N, 110W-130E PWFE82.TIF 24HR Pacific Wind/Wave Forecast VT12Z 30S-30N, 110W-130E PWFE84.TIF 24HR Pacific Wind/Wave Forecast (Most Current) PWFE11.TIF 48HR Pacific Wind/Wave Forecast VT00Z 30S-30N, 110W-130E PJFI89.TIF 48HR Pacific Wind/Wave Forecast VT12Z 30S-30N, 110W-130E PJFI91.TIF 48HR Pacific Wind/Wave Forecast (Most Current) PJFI10.TIF 72HR Pacific Sea State Forecast VT00Z 30S-30N, 110W-130E PJFK89.TIF 72HR Pacific Sea State Forecast VT12Z 30S-30N, 110W-130E PJFK91.TIF 72HR Pacific Sea State Forecast (Most Current) PJFK10.TIF WIND/WAVE CHARTS - SE PACIFIC Tropical Sea State Analysis VT00Z 20S-30N, E of 145W PKFA88.TIF Tropical Sea State Analysis VT12Z 20S-30N, E of 145W PKFA89.TIF Tropical Sea State Analysis (Most Current) PKFA10.TIF 24HR Wind/Wave Forecast VT00Z 20S-30N, E of 145W PWFE01.TIF 24HR Wind/Wave Forecast VT12Z 20S-30N, E of 145W PWFE03.TIF 24HR Wind/Wave Forecast (Most Current) PWFE10.TIF 48HR Wind/Wave Forecast VT00Z 20S-30N, E of 145W PWFI88.TIF 48HR Wind/Wave Forecast VT12Z 20S-30N, E of 145W PWFI90.TIF 48HR Wind/Wave Forecast (Most Current) PWFI10.TIF **48HR Wave Period/Swell Direction VT00Z 20S-30N, E of 145W PJFI87.TIF 48HR Wave Period/Swell Direction VT12Z 20S-30N, E of 145W PJFI88.TIF 48HR Wave Period/Swell Direction (Most Current) PJFI11.TIF 72HR Wind/Wave Forecast VT00Z 20S-30N, E of 145W PWFK92.TIF 72HR Wind/Wave Forecast VT12Z 20S-30N, E of 145W PWFK93.TIF 72HR Wind/Wave Forecast (Most Current) PWFK10.TIF 72HR Wave Period/Swell Direction VT00Z 20S-30N, E of 145W PJFK93.TIF WIND/WAVE CHARTS - NORTH PACIFIC 00Z Sea State Analysis 20N-70N, 115W-135E PJBA99.TIF **00Z Wind/Wave Analysis 18N-62N, E OF 157W PWBA88.TIF **06Z Wind/Wave Analysis 18N-62N, E OF 157W PWBB88.TIF **12Z Wind/Wave Analysis 18N-62N, E OF 157W PWBA89.TIF **18Z Wind/Wave Analysis 18N-62N, E OF 157W PWBD89.TIF ** Wind/Wave Analysis 18N-62N, E OF 157W (Most Current) PWBA90.TIF 24HR Wind/Wave Forecast VT00Z 18N-62N, E OF 157W PWBE98.TIF 24HR Wind/Wave Forecast VT12Z 18N-62N, E OF 157W PWBE99.TIF 24HR Wind/Wave Forecast (Most Current) PWBE10.TIF 48HR Wind/Wave Forecast VT00Z 20N-70N, 115W-135E PJBI98.TIF 48HR Wind/Wave Forecast VT12Z 20N-70N, 115W-135E PJBI99.TIF 48HR Wind Wave Forecast (Most Current) PJBI10.TIF 48HR Wave Period/Swell Direction VT00Z 20N-70N, 115W-135E PJBI88.TIF **48HR Wave Period/Swell Direction VT12Z 20N-70N, 115W-135E PJBI89.TIF 48HR Wave Period/Swell Direction (Most Current) PJBI20.TIF 96HR Wind/Wave Forecast VT12Z 20N-70N, 115W-135E PJBM98.TIF 96HR Wave Period/Swell Direction VT12Z 20N-70N, 115W-135E PJBM88.TIF SURFACE CHARTS - CENTRAL PACIFIC ** North Pacific Preliminary Analysis (Most Current) PYPA00.TIF 00Z Pacific Surface Analysis EQ-50N, 110W-130E PPBA88.TIF 06Z Pacific Surface Analysis EQ-50N, 110W-130E PPBA89.TIF 12Z Pacific Surface Analysis EQ-50N, 110W-130E PPBA90.TIF 18Z Pacific Surface Analysis EQ-50N, 110W-130E PPBA91.TIF Pacific Surface Analysis (Most Current) PPBA11.TIF 00Z Pacific Streamline Analysis 30S-30N, 110W-130E PWFA90.TIF 06Z Pacific Streamline Analysis 30S-30N, 110W-130E PWFA91.TIF 12Z Pacific Streamline Analysis 30S-30N, 110W-130E PWFA92.TIF 18Z Pacific Streamline Analysis 30S-30N, 110W-130E PWFA93.TIF Pacific Streamline Analysis (Most Current) PWFA11.TIF 03Z Significant Cloud Features 30S-50N, 110W-160E PBFA99.TIF 15Z Significant Cloud Features 30S-50N, 110W-160E PBFC99.TIF Significant Cloud Features (Most Current) PBFA11.TIF 24HR Pacific Surface Forecast VT00Z 30S-50N 110W-130E PYFE87.TIF 24HR Pacific Surface Forecast VT12Z 30S-50N 110W-130E PYFE88.TIF 24HR Pacific Surface Forecast (Most Current) PYFE11.TIF 48HR Pacific Surface Forecast VT00Z 30S-50N 110W-130E PYFI87.TIF 48HR Pacific Surface Forecast VT12Z 30S-50N 110W-130E PYFI88.TIF 48HR Pacific Surface Forecast (Most Current) PYFI11.TIF 72HR Pacific Surface Forecast VT00Z 30S-50N 110W-130E PYFK87.TIF 72HR Pacific Surface Forecast VT12Z 30S-50N 110W-130E PYFK88.TIF 72HR Pacific Surface Forecast (Most Current) PYFK11.TIF SURFACE CHARTS - SE PACIFIC 00Z East Pacific Surface Analysis 20S-30N, E of 145W PYFA96.TIF 06Z East Pacific Surface Analysis 20S-30N, E of 145W PYFA97.TIF 12Z East Pacific Surface Analysis 20S-30N, E of 145W PYFA98.TIF 18Z East Pacific Surface Analysis 20S-30N, E of 145W PYFA99.TIF East Pacific Surface Analysis Most Current PYFA90.TIF **00Z U.S./Tropical Surface Analysis 5S-50N,55W-125W PYEB86.TIF **06Z U.S./Tropical Surface Analysis 5S-50N,55W-125W PYEB87.TIF **12Z U.S./Tropical Surface Analysis 5S-50N,55W-125W PYEB85.TIF **18Z U.S./Tropical Surface Analysis 5S-50N,55W-125W PYEB88.TIF ** U.S./Tropical Surface Analysis 5S-50N,55W-125W PYEB11.TIF 24HR Tropical Surface Forecast VT00 20S-30N, E of 145W PYFE79.TIF 24HR Tropical Surface Forecast VT12 20S-30N, E of 145W PYFE80.TIF 24HR Tropical Surface Forecast(Most Current) PYFE10.TIF 48HR Tropical Surface Forecast VT00 20S-30N, E of 145W PYFI81.TIF 48HR Tropical Surface Forecast VT12 20S-30N, E of 145W PYFI82.TIF 48HR Tropical Surface Forecast(Most Current) PYFI10.TIF 72HR Tropical Surface Forecast VT00 20S-30N, E of 145W PYFK83.TIF 72HR Tropical Surface Forecast VT12 20S-30N, E of 145W PYFK84.TIF 72HR Tropical Surface Forecast (Most Current) PYFK10.TIF SURFACE CHARTS - NORTH PACIFIC 00Z Surface Analysis NE Pacific (Part 1) 20N-70W, 115W-175W PYBA01.TIF 00Z Surface Analysis NW Pacific (Part 2) 20N-70W, 175W-135E PYBA02.TIF 06Z Surface Analysis NE Pacific (Part 1) 20N-70W, 115W-175W PYBA03.TIF 06Z Surface Analysis NW Pacific (Part 2) 20N-70W, 175W-135E PYBA04.TIF 12Z Surface Analysis NE Pacific (Part 1) 20N-70W, 115W-175W PYBA05.TIF 12Z Surface Analysis NW Pacific (Part 2) 20N-70W, 175W-135E PYBA06.TIF 18Z Surface Analysis NE Pacific (Part 1) 20N-70W, 115W-175W PYBA07.TIF 18Z Surface Analysis NW Pacific (Part 2) 20N-70W, 175W-135E PYBA08.TIF Surface Analysis, Part 1 (Most Current) PYBA90.TIF Surface Analysis, Part 2 (Most Current) PYBA91.TIF **24HR Surface Forecast VT00Z 18N-62W, E of 157W PPBE00.TIF **24HR Surface Forecast VT12Z 18N-62W, E of 157W PPBE01.TIF **24HR Surface Forecast (Most Current) PPBE10.TIF 48HR Surface Forecast VT00Z 20N-70W, 115W-135E PWBI98.TIF 48HR Surface Forecast VT12Z 20N-70W, 115W-135E PWBI99.TIF 48HR Surface Forecast (Most Current) PWBI10.TIF 96HR Surface Forecast VT12Z 20N-70W, 115W-135E PWBM99.TIF TROPICAL CYCLONE CHARTS - PACIFIC 72 HR Tropical Cyclone Danger Area VT 03Z 0N-40N, 80W-170E PWFK03.TIF 72 HR Tropical Cyclone Danger Area VT 09Z 0N-40N, 80W-170E PWFK09.TIF 72 HR Tropical Cyclone Danger Area VT 15Z 0N-40N, 80W-170E PWFK15.TIF 72 HR Tropical Cyclone Danger Area VT 21Z 0N-40N, 80W-170E PWFK21.TIF 72 HR Tropical Cyclone Danger Area (Most Current) PWFK12.TIF SEA SURFACE TEMPERATURE CHARTS Pacific SST Chart 55N-EQ, 110W-160E PTFA88.TIF SATELLITE IMAGERY (IR) 00Z Eastern Pacific Satellite Image 05S-55N, 110W-155E evpz00.jpg 06Z Eastern Pacific Satellite Image 05S-55N, 110W-155E evpz06.jpg 12Z Eastern Pacific Satellite Image 05S-55N, 110W-155E evpz12.jpg 18Z Eastern Pacific Satellite Image 05S-55N, 110W-155E evpz18.jpg Eastern Pacific Satellite Image (Most Current) evpz11.jpg 00Z Southwest Pacific Satellite Image 40S-05N, 130W-165E evps00.jpg 06Z Southwest Pacific Satellite Image 40S-05N, 130W-165E evps06.jpg 12Z Southwest Pacific Satellite Image 40S-05N, 130W-165E evps12.jpg 18Z Southwest Pacific Satellite Image 40S-05N, 130W-165E evps18.jpg Southwest Pacific Satellite Image (Most Current) evps11.jpg **00Z Tropical East Pacific Satellite Image 20S-40N,E of 145W evpn02.jpg 06Z Tropical East Pacific Satellite Image 20S-40N,E of 145W evpn07.jpg **12Z Tropical East Pacific Satellite Image 20S-40N,E of 145W evpn04.jpg 18Z Tropical East Pacific Satellite Image 20S-40N,E of 145W evpn08.jpg Tropical East Pacific Satellite Image (MOST CURRENT) evpn10.jpg **00Z Pacific Satellite Image 05N-55N, E of 180W evpn01.jpg 06Z Pacific Satellite Image 05N-55N, E of 180W evpn06.jpg **12Z Pacific Satellite Image 05N-55N, E of 180W evpn12.jpg 18Z Pacific Satellite Image 05N-55N, E of 180W evpn18.jpg Pacific Satellite Image (MOST CURRENT) evpn99.jpg SCHEDULE INFORMATION Radiofax Schedule (Honolulu, HI) Part I PLBZ07.TIF Radiofax Schedule (Honolulu, HI) Part II PLBZ09.TIF Radiofax Schedule (DOS Text Version) hfhi.txt Test/Map Symbols/General Notice PLBZ08.TIF Internet File Names (This file) rfaxhi.txt ** Not transmitted via Honolulu radiofax but listed here for convenience