Weather

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fxus62 kmfl 061357 aaa 
afdmfl 


Area forecast discussion 
National Weather Service Miami Florida 
955 am EDT Monday Oct 6 2008 


Update... 
frontal boundary which plagued South Florida this past weekend is 
now across central and northern sections of the peninsula where most 
of the showers and thunderstorms are concentrated this morning. Over South 
Florida, the bulk of the showers has been across Palm Beach County 
in closer proximity to the front and deeper moisture. 


Morning sounding analysis indicates a fairly high moisture gradient 
over South Florida, with precipitation water ranging from 1.70 inches at 
Key West to around 2 inches north of Lake Okeechobee. Farther 
downstream at Nassau, the precipitation water is a much lower 1.29 inches. 
Don't believe this dry air will make it intact this far west, but 
nevertheless expect southern parts of our area to see a bit more 
drying compared to areas around Lake Okeechobee. Bottom line to all 
this is little change to current forecast as previous shift had very 
good handle on weather pattern. Only minor changes to today's 
forecast was to increase the winds very slightly over Atlantic and east 
metropolitan areas, introduced a sea breeze to West Coast this afternoon, 
and lowered interior maximum temperatures 2-3 degrees. /Molleda 


&& 


Previous aviation discussion issued 734 am... 
VFR conditions expected through the period at East Coast 
terminals. Easterly flow will continue fairly steady through the 
period and this will continue to blow isolated showers onshore 
across the East Coast terminals. Showers should be fast moving 
with only brief periods of moderate rainfall and possibly brief 
ceilings around 2500ft. For kapf...stratus continues at the terminal 
but should burn off by 13z with clouds scattering out. A sea 
breeze will develop by early afternoon and the increased 
convergence should lead to a few thunderstorms and rain in the afternoon with brief 
ceiling/visibility reductions possible. 


/Strassberg 


&& 


Previous discussion... /issued 354 am EDT Monday Oct 6 2008/ 


Short term...today and tonight...06z surface observation across the peninsula 
show the presence of a boundary across south-central Florida with 
a moister air mass from Lake Okeechobee southward. Models 
(especially gfs) do not show much movement of this boundary and 
basically leave it just north of the lake today. This will likely 
act as a focusing mechanism for showers/thunderstorms across the lake region 
this afternoon. GFS also shows upper level diffluence across most of 
the peninsula this afternoon. More sunshine this morning across 
Mainland South Florida will also provide enough heating to start 
convection over the area. With this in mind, decided to go with 
high scattered probability of precipitation across the lake region and northwest interior portions of 
South Florida with significantly lower probability of precipitation across the extreme 
southern sections of the peninsula, as that area is farthest away 
from the boundary. This boundary then should become rather diffuse 
by tonight with only leftover showers mainly over the Atlantic waters. 


More sunshine today will also mean higher afternoon temps, 
especially across southern sections where temperatures could reach middle 
90s across Collier County and The Everglades. Heat indices across 
that region could hover around 105 during the early afternoon hours. 


Tuesday through Wednesday...although drier than previous days, we 
could still see significant convective activity, especially across 
eastern sections as an east low level flow will contribute to 
increase low level convergence. Models also indicate continued upper 
level divergence/diff as several weak disturbances move around the top of a 
deep layer ridge over the Gulf of mex. 


Long term...Thursday through Sunday...GFS still shows a short 
wave digging southeast to southeastern U.S. And dragging a front to central 
Florida by Thursday night. However, this system looses support 
quite rapidly as the main branch of the polar jet moves northward 
and the front dissipates before reaching the local area. Mainland 
S. Florida will therefore remain under a rather deep east flow and will 
return to more climatological conditions with early 
morning/nighttime showers East Coast and afternoon convection 
mainly interior/west. 


Marine...mostly east winds at 15 knots or less with seas at 4 feet 
or less should prevail through this period. Surface winds could shift to 
more southeast-S Wednesday as the front moves into north-central Florida but 
will shift back to mostly east by Thursday as the front retrogrades 
and dissipates. 


Fire weather...no concerns at this time. 


&& 


Preliminary point temps/pops... 
West Palm Beach 88 77 85 76 / 40 20 50 30 
Fort Lauderdale 89 78 86 78 / 30 20 50 30 
Miami 90 78 87 77 / 20 20 50 30 
Naples 90 74 89 73 / 30 10 40 20 


&& 


Mfl watches/warnings/advisories... 
Florida...none. 
Am...none. 
GM...none. 
&& 


$$ 


Long term...47/rhg 
short term/aviation...15/Jr