NWS Melbourne Marine Web Letter
May 2010

Start of Wet Season
Late May to early June is the typical time for the start of the east central Florida wet season, where there is a pronounced increase in the frequency of rainfall.  This increase in rainfall is primarily due to thunderstorms.  Boaters therefore need to be aware of not just the wind/sea forecast, but also what the prospects are for storms each day.  In May and June of last year, there were 5 drowning deaths in east central Florida when strong thunderstorm winds capsized boats.  The highest probability for storms is in the afternoon, so this is the time that boaters need to be most cautious.

The NWS Melbourne Hazardous Weather Outlook will include a Marine Thunderstorm Gust section to provide details of storm initiation and movement.  One danger that many do not think of is that strong winds can flow out well ahead of the lightning and heavy rainfall associated with a storm.  So the best thing to do is to return to safe harbor at the first sign of a developing storm.
 
Wave Periods Matter!
I want to continue to emphasize the importance of wave periods to mariners.  I have discussed this topic in previous web letters.  Additionally, a case study on the web looks at common wave conditions in east central Florida and how important wave periods are to boaters, even at relatively low wave heights.  To provide improved service to boaters, NWS Melbourne’s Coastal Waters Forecast began to include the dominant wave period late in 2009.  
The wave periods are not available in the point and click forecasts generated at our web site. To get the wave periods, consult the forecaster produced version of the Coastal Waters Forecast. Additionally, the NOAA Wave Watch Model has forecast wave periods out to 7 days.
 
Nearshore Wave Model
Forecasters have started to incorporate output from a nearshore wave model into the daily forecasts.  This model utilizes shallow water wave physics and hence there is more confidence in the wave data it generates along the coast.  Of course, if the wind forecast is inaccurate, then the wave data will also be wrong. Boaters need to remember that the ocean has a vast expanse and the amount of wind data is small, so there will often be areas where the forecast is inaccurate. 
 
Talk to a Forecaster--anytime
We continue to receive relatively few calls to talk with the marine forecaster. If you have marine weather questions, such as for a trip or tournament, a marine forecaster can be reached 24x7 at 321-255-0212—after hours Ext. 242.


Randy Lascody  email.

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