Weather

131 
fxus62 kkey 112000 
afdkey 


Area forecast discussion for the Florida Keys 
National Weather Service Key West Florida 
400 PM EDT Sat Oct 11 2008 


Discussion... 
currently - surface analysis indicates an inverted trough hanging 
tough just offshore of the southeastern states stretching across 
Florida. This trough...associated with an aging deep layered cut off 
low....is tucked under the southern periphery of a building high 
pressure system centered over New England. Surface winds have not 
come up yet...and winds have held in the light range out of the 
northeast to east. A favorable lower tropospheric flow has resulted 
in one round of island cloudlines affecting the Lower Keys so far 
today. Currently...Doppler radar indicates only a few showers in 
Keys waters...as well as a fairly active East Coast sea breeze over 
Miami-Dade and scattered activity over the western Bahamas. Day time 
highs were in the upper 80s today...with dew point temperatures 
holding in the middle 70s. 


Forecast - the previously mentioned lower tropospheric 
trough...along with the middle and upper level circulations will dampen 
out and shift westward over the next 24 hours by the building high 
over the eastern states. Increased low level moisture...and 
associated convection on the eastern periphery of the trough will 
likely also shift westward across our area tonight. For this 
reason...will raise probability of precipitation a notch to low chance for tonight. Light 
northeast to east winds will gradually firm up out of the east at 10 
to 15 miles per hour by Sunday morning. 


Through the remainder of the weekend and the beginning of next 
week...the high pressure system will gradually re-center itself over 
the Carolinas...and the local pressure gradient will tighten 
considerably. Gentle to moderate winds will fill in across the Keys 
tonight...and increase further to fresh and perhaps strong breezes 
by late Monday. While the Keys will increasingly fall under the 
control of the large high high to our north...ample lower level 
moisture riding along the synoptic flow will keep a chance of 
precipitation in the forecast until Wednesday. At that time...a much 
drier air mass of Continental origin will have reached the Keys and 
strong middle and upper level ridging will have moved overhead. Only a 
slight chance of precipitation will be advertised from middle week and 
beyond. 


&& 


Marine... 
the tenacious trough over Florida is expected to get swept westward 
tonight...and an increasingly steep gradient will build in across 
the Keys through the beginning of next week. No cautions or 
advisories are expected tonight...however a caution will likely be 
required sometime tomorrow...and a Small Craft Advisory by Monday 
night. There is some indication that winds could be strong (20 to 25 
knots and gusty) Monday night through middle week. Winds will gradually 
weaken over the second half of the week as the high pressure system 
weakens. 
&& 


Aviation... 
VFR conditions will prevail at the keyw and kmth island terminals 
tonight. There is a chance for another round of convective cloud 
lines which may create brief periods of MVFR ceilings/visible over keyw 
during the late afternoon/early evening. Surface winds will be from 
the northeast at less than 10 knots. 
&& 


Preliminary point temps/pops... 
Key West 79 86 80 86 / 30 30 30 30 
Marathon 79 88 80 88 / 30 30 30 30 
&& 


Key watches/warnings/advisories... 
Florida...none. 
GM...none. 
&& 


$$ 


11/al/ 


Visit US on the web at www.Weather.Gov/keywest