NWS Melbourne Marine Web Letter
September 2011
(For Marine Forecast Questions 24/7: 321-255-0212 ext. 242)
 

Small Craft Advisory for Hazardous Seas
 
Large swell events result in criteria being met for a Small Craft Advisory (seas 7 feet or greater). However, when winds are rather light (10 knots or less), there is little problem in the open ocean for small boats. Therefore, I have been looking at ways to limit the number of Small Craft Advisories for Hazardous Seas when winds are light. Initial thoughts are that we will not have one in effect unless winds are forecast to be at least 10-15 knots.  
 
The main boating concern during large swell/light wind events is that traversing inlets can be especially hazardous during the outgoing tide. There is an option for having a Small Craft Advisory for Rough Bar during these situations. I am not sure if introducing a new kind of Small Craft Advisory for east central Florida is the best course of action though. Instead, a Small Craft Exercise Caution statement with mention of hazardous conditions at inlets is more familiar terminology, and one that I would favor. I welcome any input on this topic.

 
Swan Model
 
We continue to run the SWAN model at least twice a day.   Some nice graphics from this model are available on the web:

http://innovation.srh.noaa.gov/swan/swanloop.php?sid=MLB
 
 
Fall Season
 
During September, we often begin to experience a taste of the Fall weather pattern when large, continental high pressure systems push off the mid Atlantic coast behind cold fronts. The resultant northeast-east wind flow can become quite breezy and necessitate several days with Small Craft Advisories. As we get later into the season, cold fronts become stronger and a more significant decrease in moisture and temperatures occur. This represents the start of the Dry Season which typically occurs in mid to late October.
 
Since La Nina conditions have returned and are forecast to persist into early next year, generally drier than normal weather is anticipated for this Dry Season. However, there will likely be a month or two where fronts are quite strong and produce several periods of poor boating conditions. The timing of this depends on the occurrence of the negative phase of the Arctic Oscillation (which brought some cold, windy weather last winter when there was a rather strong La Nina event). 
 
Of course, the hurricane season lasts through November, so periods of large swells can still occur. A persistent trough over the eastern U. S. has steered storms east of the state so far. However, the chance for storms moving north out of the northwest Caribbean Sea increases during the latter half of the hurricane season, especially during October.
 
 
Talks

If you are interested in having me give a talk about marine forecasting, the best way to contact me is via email.

Randy Lascody

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