Area Forecast Discussion
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FXUS62 KKEY 201406

Area Forecast Discussion
National Weather Service Key West FL
Issued by National Weather Service MELBOURNE FL
1006 AM EDT Wed Sep 20 2017

12z Key West and Miami soundings indicate a pronounced dry layer
between 700-500 mbs with PWATs ranging from 1.52 inches at KEY to
1.39 inches at MFL. Water vapor imagery and RAP 250 mb height
analysis indicates an upper level trough stretching from central
Cuba to the NW Bahamas with mid to upper level dry air noted near
the upper Keys and off the SE FL coast. At the surface a weak
frontal trough will drop into south FL toward evening north of the
forecast area but not have an impact on today`s dry forecast.
Light surface winds this morning will become generally light
southeast this afternoon. Highs around 90 along the island chain
this afternoon. No significant changes to afternoon forecast.


.PREVIOUS SHORT TERM...(Today-Friday night)...Global model guidance
is in decent agreement showing initial advection of drier air
today, slowly give way to increasing moisture and rain chances
through late week (and beyond). Kept the overall increasing POP
trend from around 20 percent Thursday to 40-50 percent
Friday/Friday night. Trade flow gradually increases Thursday, then
backs and freshens a bit more on Friday as the peripheral
circulation of major Hurricane Maria begins to exert a little more
influence locally. The center of Maria will move northward
remaining east of the Bahamas, while reaching the latitude of the
Straits by mid day Friday and then the southern peninsula by late
Friday night. Maxes around 90-91F the next couple days will taper
back by a couple degrees as winds increase. Mins 80-82F.


Current marine forecast in good shape with generally light
easterly flow for Atlc waters south of the Islands to light and
variable winds becoming south-southwest across portions of Florida
Bay and the Gulf waters. Slightly higher seas in the gulf stream
from Ocean Reef to Craig Key to 2 to 4 feet.


VFR. SE winds below 10KT after 14Z, then backing some while
dropping to less than 5KT after 02Z tonight.




Public/Marine/Fire...Volkmer (MLB)
Aviation/Nowcasts....APA (KEY)
Data Collection......Fling (KEY)

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