Weather Information

Weather from the Web

There are a growing number of weather sites on the web.  They all provide a verity of weather forecasting services with one of their more useful tools being GRIB files.
GRIB stands for Gridded Information in Binary and is the standard format used to transmit coded weather data.  Some programs just translate these files and display the data while others interpret the data and often compare different computer models. 

1.    Bureau of Meteorology
The Bureau's online MetEye tool helps you visualise local weather observations and forecasts for any location in Australia. The forecasts use a blend of model data with the latest science, technology and expert meteorologist input to best represent expected weather and are routinely updated twice a day.
Go to http://www.bom.gov.au/australia/meteye/

For the regular local marine forcast, go to http://www.bom.gov.au/marine/ and select the WA tab at the top to see a host of free wind, wave, current, tide and prediction  tools.  The square tabs under the heading ”National Services” provide wind, tide, current and wave information that can be configured to display in combinations of information and formats.  Spend some time to work out which best suite your needs. 

2.    IMOS
http://www.imos.org.au/ is the place to go to see what is happening with the ocean currents.  Again all information on this site is free.

3.    UGRIB
https://ugrib.informer.com/  This site allows you to download a freeware application Ugrib that allows instant and fully customizable access to global weather data.  Once you register you can download install-UGRIB.exe and install Ugrib.exe on your PC.  It was designed for use on boats with limited bandwidth so the files are small.  All data provided by this program is free.

4.    PredictWind.com
https://www.predictwind.com/ is the place to start.  You can then register to take the free version or buy a subscription at one of 3 levels.    Once logged in you will be using the forecast.predictwind.com page and can select from there.  To get the most from this site spend some time reading the tutorials. This is a more sophisticated program. It allows you to change between the GFS and the CMC computer modals that often differ slightly besides using the interpretation provided by PredictWind. 

5.    Buoyweather.com
http://www.buoyweather.com/ takes you to the initial screen.  Again there is a certain amount of free information but by subscribing you can obtain a lot more.  For instance forecasts go from 2 days to 7 days and more charts become available.  Similar to PredictWind time spent reading the various explanations will enable you get the most from this worldwide site.

6.    Saildocs
http://www.saildocs.com/ is an email-based document-retrieval system for the “bandwidth-impaired”, for the delivery of text-based Internet documents either on request or by subscription. Saildocs can deliver web pages including text weather forecasts, and provides subscriptions for automatic delivery.  Additionally Saildocs provides custom grib weather-data files per request from data downloaded from NOAA/NCEP and other sources, see “gribinfo”.
It is suggested you try a number of different sites and on several occasions compare their predictions to what actually occurs, then choose a few that suit your needs at varying times before a race and then use the information provided in planning  your race.
GRIB files, synoptic charts (or gradient wind charts), and satellite pictures used in conjunction with each other give a very accurate forecast.  
For anyone sailing in the tropics tropicalstormrisk.com is excellent for tracking cyclones.

Radio Weather and Warnings

Coastal waters forecasts are for areas within 60 nautical miles of the coast.  Coastal and local waters forecasts are issued twice daily.  Updates may be issued at other times. Warnings for coastal waters are issued whenever strong winds, gales, storm force or hurricane force winds are expected. The initial warning attempts to provide around 24 hours lead-time and warnings are renewed every 6 hours. 

Terminology 
Wind speed is the average speed of the wind over a 10-minute period at a height of 10 metres above the surface 
Gusts are increases in wind speed lasting for just a few seconds.  The speeds are typically 30 to 40 per cent higher than the average wind speed, but stronger gusts are likely in the vicinity of showers, thunderstorms and frontal systems. 
Strong wind warning: 26 to 33 knots. Gale warning: 34 to 47 knots. Storm force wind warning: 48 to 63 knots. 
Wave height (trough to crest) for both sea and swell in Bureau observations and forecasts refers to ’significant wave height‘ that represents the average height of the highest one-third of the waves. 

VHF Marine Broadcasts:

HF Voice Radio Marine Broadcasts from VMW:
VMW (Wiluna) broadcasts on 4149 and 16528 kHz during daytime 7am-6pm.  At night 6pm-7am VWM broadcasts on 2056 and 6230 kHz.  
At anytime VMW may also broadcast on 8113 and 12362 kHz.

WMW Forecast and Warnings Schedule (WST):
Western Australia Forecast at 0030 /0430 / 0830 / 1230 / 1630 / 2030  hours
Weather Warnings every hour commencing 0000.
Navigation Warnings from Coast Radio Perth on 8176 kHz at 1457 and 1857 hours