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000 
FXUS62 KKEY 200754
AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
354 AM EDT Sun Aug 20 2017

.DISCUSSION...
.CURRENTLY...
A tropical wave is currently passing over the Keys area providing
wide spread showers with embedded thunderstorms. Some of the 
earlier thunderstorms were accompanied by wind gusts exceeding 35
to 40 knots. High pressure remains over the Atlantic Ocean while
the tropical wave moves through the southern edge of the ridge.
At the marine reporting station, winds are out of the east near 
10 knots outside of showers and thunderstorms. The island
terminals are reporting 5 to 10 knots from the east. 

.FORECAST...
The tropical wave will continue to march westward through this
evening, followed closely by a swath of dry air and subsidence on
the eastern flank of the wave. This dry air will drop rain chances
gradually from east to west this evening and overnight. Have
adjusted rain chances for this, but timing may need to fine tuned
in the afternoon forecast. The Atlantic ridge will rebuild across
the Florida Peninsula overnight and Monday, while the next
tropical wave moves along its southern periphery. Both moisture
and lifting will return especially Monday night and Tuesday as the
wave pushes through the area. Will keep above normal rain chances
(40 percent) for Monday night and through the end of the week as 
the Atlantic ridge takes control with deep easterly flow and
moisture. 

&&

.MARINE...
A wet Sunday with showers and thunderstorms is in store for the
Keys coastal waters. A tropical wave is moving across the area and
will begin to exit from east to northwest late today. Expect a few
thunderstorms will produce winds at least to 30 to 35 knots, so
keep monitoring the marine band if planning a day on the water.  
Dry air will move in on the heels of the wave, but the Atlantic
high pressure will rebuild and freshen breezes Sunday night and
Monday. A small craft advisory is likely for the Florida Straits
tonight and Monday. A cautionary statement will likely be 
required for the rest of the Keys coastal waters. Thereafter, the
Atlantic ridge will provide peaks and lulls in gentle to moderate
breezes through the end of the week. 

&&

.AVIATION...
VFR conditions will prevail at EYW and MTH through at least sunrise. 
IFR conditions are likely at EYW and MTH late this morning and this 
afternoon. Sustained northeast winds of 10 to 15 knots from just off 
the surface to about 3,000 feet will veer to east to southeast and 
increase to 15 to 20 knots this evening. 

&&

.CLIMATE...
On this date in Florida Keys weather history, in 1963, 2.06 inches 
of rain fell at Key West International Airport. This set the daily 
record for maximum rainfall measured in Key West on August 20th, a 
record which still stands 54 years later. Rainfall records at Key 
West date back to 1871.

&&

.PRELIMINARY POINT TEMPS/POPS...
Key West  89  80  91  81 / 70 30 20 40 
Marathon  91  80  93  81 / 70 20 20 40 

&&

.KEY WATCHES/WARNINGS/ADVISORIES...
FL...None.
GM...None.
&&

$$

Public/Marine/Fire...BWC
Aviation/Nowcasts....BS
Data Collection......DR

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