Sunday, April 7, 2013

Weather Information for Voyages in the Australian Region by Kenn Batt, BOM


Long before (say 6-12 months) you embark on any voyage, either coastal or oceanic, you need to obtain an idea of the average winds and weather (the climatology) that you may encounter.

A broad overview of what drives our Australian weather at various times of the year, can be obtained from here

To gain an idea of the average coastal wind winds at locations around the Australian coast, then check out this link

For ocean areas check this one http://cioss.coas.oregonstate.edu/cogow/

An idea of other weather elements can be gleaned from here

Check out what weather information is available to you via HF and VHF radio whilst at sea (extremely important if you don’t have internet access on board)? All this information can be obtained from this link http://www.bom.gov.au/marine/radio-sat/marine-radio-sat.shtml

How might an El Nino or La Nina impact on my voyage? Check out

At least two weeks before you plan to embark on your voyage, lock into (get in phase with) the weather. This can be achieved by monitoring computer forecast models. There are a range of different models available, some of the better ones are available from (If cruising plan to leave on a favourable weather pattern. If racing then there is generally no such option):

The Bureau of Meteorology website (ACCESS suite of models) http://www.bom.gov.au/australia/charts/viewer/index.shtml

ACCESS model (Days 1 and 2 and then the European Community model, ECMWF, for Days 3-7)

Passage Weather (GFS model from the USA)

An excellent site (free trial then payment required) for higher resolution models is http://www.predictwind.com

At least the day before you set off, on the day and whilst on your voyage, regularly work down the following checklist:

  1. Are warnings current for my area of interest? http://www.bom.gov.au/australia/warnings/index.shtml or via HF/VHF radio

  1. What is the latest weather situation?
http://www.bom.gov.au/australia/charts/synoptic_col.shtml or via the Weather Situation which accompanies a coastal or high seas forecast are broadcast on HF/VHF radio.


  1. What is the latest coastal or high seas weather forecast for my area?

[With internet access, the range of computer forecast models (listed above and more) can be accessed as well]

  1. What are the latest weather observations along the coast?

5. What is going on around me? Log wind (direction and speed), atmospheric pressure and cloud types at least every 3 hours and look for trends. This valuable information can assist you to fine-tune forecasts.  Make sure that you have a working barometer on your vessel.

Other information of interest could beTides?

http://www.bom.gov.au/oceanography/tides/ or from the tide tables that you have onboard.

Ocean Currents?
and

At the end of the day the one stop shop is http://www.bom.gov.au/marine/index.shtml

Do your homework before you depart. Whilst at sea regularly check and update the weather.




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