Wednesday, October 12, 2016

Wed Oct 12, 2016: Time to Start Your Barometer Calibration

We have a nice Low approaching the Pacific Northwest so beyond its other implications, ie gusts to 50 kts forecasted for Puget Sound, and much rain, we can look to the brighter side, and take this opportunity to calibrate barometers.

Just start a log and write down every few hours or so what your barometer reads... and do not move its location, meaning do not change its elevation above sea level.

Then by end of week end you can look up the local pressure reported for your nearest location and compare the two.

We expect a drop from about the present 1024 down to 993 tomorrow around 4 to 6 pm.

GFS forecast for Seattle Area

In Seattle area, check your pressures at WPOW1, the West Point Lighthouse, which presents a graph like below, but also tabulated data.

You can also use custom pressure links we have set up at

Or check "UW meteograms" from link at for another prediction. Note their statement that these take a few minutes to build once requested.

For those away from Seattle, find your closest reference station at

UW meteogram. 

Here is the latest weather map, from 5 am this morning.

Here is our main reference for barometer use and calibration

If you get good data and want help analyzing it, then just send us a copy of it to  ie two columns, one of time and date, one of pressure from your barometer. Include your lat lon and the height of your barometer above the ground. We can find the ground height from here.  Record pressures to the nearest tenth of a mb.

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