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811
FXUS62 KKEY 041329
AFDKEY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
930 AM EDT WED MAY 4 2016

...SOME STRONG SHOWERS AND THUNDERSTORMS LIKELY WITH A FEW
   SEVERE THUNDERSTORMS POSSIBLE LATE THIS AFTERNOON AND EVENING...

.DISCUSSION...
.CURRENTLY...EARLY VISIBLE SATELLITE PHOTOGRAPHS SHOW CLOUDS ARE ON
THE INCREASE WITH TEMPERATURES ALREADY IN THE LOWER TO MID 80S ALONG
THE ISLAND CHAIN. MEANWHILE...LOCAL RADARS ARE VOID OF ANY
PRECIPITATION ECHOES IN OUR REGION. SURFACE WISE...A PRE-FRONTAL
TROUGH IS DRAPED FROM APALACHEE  BAY...TO THE EXTREME SOUTH CENTRAL
GULF OF MEXICO...WHILE A EXITING WESTERN ATLANTIC RIDGE IS ALIGNED
ACROSS THE ARCHIPELAGO OF CUBA. WINDS ARE SOUTH TO SOUTHWEST RANGING
FROM 10 TO 15 KNOTS ON OUR MARINE DISTRICT. OTHERWISE...OUR MORNING
SOUNDING REVEALS A MODERATELY UNSTABLE (CAPE AROUND 2200 J/KG) AND
MOIST (PWAT 1.90 INCHES) AIRMASS IN PLACE. MODEST...FAIRLY
UNIDIRECTIONAL SOUTHWEST WINDS REACH WELL INTO THE
TROPOSPHERE...BEFORE TURNING WEST AND INTENSIFYING ABOVE.

.SHORT TERM (REST OF TODAY)...
A COUPLE OF MID AND UPPER LEVEL DISTURBANCES...LOCATED IN THE SOUTH
CENTRAL GULF OF MEXICO AND THE LOUISIANA COAST WILL PLOW EASTWARD
RESULTING IN AN INCREASING AND STRONG SOUTHWEST FLOW. BECAUSE OF
THIS PROGRESSIVE AND DEEPENING TROUGH...A SURFACE TROUGH IN THE EAST
CENTRAL GULF OF MEXICO WILL SHARPEN AND DRIVE EASTWARD AND THROUGH
OUR ENTIRE COUNTY WARNING AREA...FROM LATE THIS AFTERNOON THROUGH
EARLY TONIGHT. WITH AN ABUNDANCE OF MOISTURE AND MODERATE
INSTABILITY...LOW LEVEL MASS CONVERGENCE COMBINED WITH LARGE SCALE
LIFT WILL RESULT IN DEVELOPING NUMEROUS SHOWERS AND
THUNDERSTORMS...SOME OF WHICH WILL LIKELY BE STRONG...AND A FEW MAY
BE SEVERE. OTHERWISE...CLOUDS AND SOUTHWEST WINDS WILL BE ON THE
INCREASE WITH TEMPERATURES TOPPING OFF IN THE MID AND UPPER 80S.
TIMING WISE...IT APPERARS AN EASTWARD MOVING PRE-FRONTAL BAND OF
SHOWERS AND THUNDERSTORMS WILL ARRIVE IN THE LOWER KEYS BETWEEN 4
AND 5 PM. WITH THAT SAID...WILL UPDATE THE ZONE FORECAST LATER TO
ADD MORE SPECIFIC TIMING OF THE ONSET OF PRECIPITATION.

&&

.MARINE...
MARINERS SHOULD BE ALERT FOR INCREASING WINDS AND BUILDING SEAS
AHEAD OF A PROLIFERATION OF SHOWERS AND THUNDERSTORMS...SOME OF
WHICH WILL LIKELY BE STRONG FROM MID TO LATE AFTERNOON INTO EARLY
TONIGHT. IN ADDITION...A SMALL CRAFT ADVISORY WILL LIKELY BE
REQUIRED FOR ALL KEYS COASTAL WATERS FROM LATE THIS AFTERNOON UNTIL
AT LEAST MIDNIGHT.

&&

.AVIATION...
VFR AND GENTLE SOUTHWEST BREEZES WILL PREVAIL AT THE EYW AND MTH
TERMINALS THIS MORNING. SHOWERS AND THUNDERSTORMS APPEAR LIKELY FOR
BOTH TERMINALS BETWEEN 20Z AND 04Z. CONVECTIVE MODE WILL LIKELY  FAVOR
THE DEVELOPMENT OF SOLID LINE OF SHOWERS AND STORMS. BOTH TERMINALS
CAN EXPECT IFR CIG/VIS AND CONVECTIVE WIND GUSTS APPROACHING 35
KNOTS. THESE STORMS WILL CLEAR FROM WEST TO EAST LIKELY AFTER 05-
07Z.

&&

.CLIMATE...
IN 1977...THE DAILY RECORD RAINFALL OF 5.33" WAS RECORDED IN KEY
WEST. RAINFALL RECORDS HAVE BEEN KEPT SINCE 1871.

&&

.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...SMALL CRAFT ADVISORY GMZ033-034.

&&

$$

PUBLIC/MARINE.........APA
AVIATION/NOWCASTS.....KN
DATA COLLECTION.......EV

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