Preview of NWS' New Version of Forecast
This preview is not operational and should not be used for support decisions.

Area Forecast Discussion (AFD)

Issued by Key West, FL (KEY)

                            
000
FXUS62 KKEY 201802
AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
202 PM EDT Sun May 20 2018

.DISCUSSION...
.CURRENTLY...
KBYX detects scattered showers and isolated thunderstorms
throughout the forecast area. Skies over the island chain are
mostly cloudy. Winds over land are east to southeast near 15 mph.
C-MAN winds, on average, are east to southeast at 15 to 20 knots.
Temperatures are in the lower 80s.  

.SHORT TERM (Tonight through Tuesday night)...
A trough of low pressure will progress northwestward through the
northeastern Gulf of Mexico tonight through Tuesday. An Atlantic
ridge of high pressure will build across the Southeastern United
States Tuesday night. Rain chances in the short term portion of
the forecast will be well above normal for this time of year. 

&&

.LONG TERM (Wednesday through Sunday)...
The aforementioned Atlantic ridge of high pressure over the
Southeastern United States will shift southward down the Florida
peninsula Wednesday, before retreating eastward Wednesday night
and Thursday. A broad area of low pressure may develop over the
northwestern Caribbean Sea Thursday night. This area of low
pressure could progress northward Friday into the upcoming
weekend. Forecast uncertainty is high Thursday night through 
Saturday. Rain chances in the long term portion of the forecast 
will be highest Wednesday through Friday. 

&&

.MARINE...
A Small Craft Advisory is in effect for the coastal waters of the
Florida Straits tonight due to sustained east to southeast winds
of 15 to 20 knots. A Small Craft Advisory will likely be required
for all Keys coastal waters Monday through Tuesday. A Small Craft
Advisory may be required for the coastal waters of the Florida 
Straits Tuesday night. No advisories expected Wednesday through at
least Thursday. A Small Craft Advisory may be required for the 
coastal waters of the Florida Straits Thursday night and Friday. A
Small Craft Advisory may be required for all Keys coastal waters 
Friday night.

&&

.AVIATION...
Wet pattern will persist at the EYW and MTH terminals. Both
terminals have experienced LIFR conditions in the past six hours,
and there is nothing to rule out additional impacts through the 
forecast period. Confidence in timing showers and thunderstorms 
remains poor at this time. Storm motion has increased to 15 knots 
or greater, and upstream, in-situ development continues. Both 
terminals can expect temporary periods of IFR VIS, MVFR CIGS, 
accompanied by convective wind gusts near 25 knots.

&&

.CLIMATE...
On this date in Florida Keys weather history, in 1932, 3.83 inches
of rain fell in Key West. This set the daily record for maximum
rainfall measured in Key West on May 20th, a record which still
stands 86 years later. Rainfall records at Key West date back to
1871.

&&

.PRELIMINARY POINT TEMPS/POPS...
Key West  75 83 76 83 / 80 70 70 70 
Marathon  76 84 76 85 / 80 70 70 70 

&&

.KEY WATCHES/WARNINGS/ADVISORIES...
FL...None.
GM...Small Craft Advisory for GMZ052>055-072>075.

&&

$$

Public/Marine/Fire...BS
Aviation/Nowcasts....CLR
Data Collection......CLR

Visit us on the web at weather.gov/key

Follow us on Facebook and Twitter at:
www.facebook.com/nwskeywest
www.twitter.com/nwskeywest