589 
fxus62 kkey 200319 
afdkey 


Area forecast discussion for the Florida Keys 
National Weather Service Key West Florida 
1020 PM EST Wednesday Nov 19 2008 


Discussion... 
currently... 
skies are clear over the island chain and northward...with partly to 
mostly cloudy skies on the Atlantic waters. Temperatures are in the 
lower to middle 60s with north to northeast winds of around 15 miles per hour. 
Surface wise...high pressure (1026 mb) is over northern Florida and 
the adjacent Gulf of Mexico...with another weaker cold front draped 
from the Great Lakes to central Oklahoma. Across the marine 
district...C-man station platform observations indicate north to 
northeast winds of 15 to 20 knots...while local radars are not 
detecting any significant precipitation. Otherwise...our evening 
sounding reveals an extremely dry (pwat .40 inches) airmass in 
place...but winds have veered quickly over the last 24 hours to 
northeast to east below 800 mb. 


Short term (overnight)... 
with the land breeze over South Florida setting up...a low level 
northwest trajectory should keep most of the stratocumulus offshore 
of the island chain so mostly clear skies with no mention of probability of precipitation is 
on target. But now for the most tricky part of the forecast. Cold 
air advection has ceased and gentle to moderate north to northeast 
winds blowing across water temperatures in the middle to upper 60s 
should keep low temperatures primarily in the lower 60s over most 
island communities. However...cold air drainage off the South 
Florida Mainland should allow temperatures to fall into the middle and 
upper 50s over the extreme Upper Keys. Since the current forecast is 
in bounds...no adjustments are planned. 


&& 


Marine... 
our evening rawindsonde depicts north to northeast winds of 15 and 
14 knots at 1 and 2 thousand feet respectively...which matches the 
kbyx vwp but the Cudjoe Key wind profiler shows 15 to 20 knots. High 
pressure over the northeast Gulf of Mexico will slowly settle 
southward over the next 12 to 24 hours...so after this last minor 
wind surge associated with the Mainland cooling...winds will abate 
substantially Thursday afternoon and evening. But until then...a 
Small Craft Advisory for hazardous seas will be extended for the 
Atlantic waters until 10z...with near 15 knots elsewhere. Looking 
ahead...another wind surge will occur late Friday and Friday night 
when a Small Craft Advisory will be required on the Atlantic waters 
and an exercise caution elsewhere. 


&& 


Aviation... 
VFR conditions will prevail overnight at the Key West and Marathon 
terminals...with mostly clear skies expected and light north winds. 


&& 


Key watches/warnings/advisories... 
Florida...none. 
GM...Small Craft Advisory due to hazardous seas for the Atlantic 
waters. 


&& 


$$ 


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