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000
FXUS62 KKEY 111530
AFDKEY

AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
1030 AM EST WED DEC 11 2013

.DISCUSSION...IN THE MID AND UPPER LEVELS...(700-200 MB)...LATEST
AVAILABLE IR IMAGERY OVERLAID WITH MODEL STREAMLINE ANALYSIS AS OF
900 AM DEPICT A DEEP AND COLD CYCLONIC MID AND UPPER FLOW PATTERN
ENCOMPASSING THE BREADTH OF THE CONUS...FROM THE SIERRA NEVADA TO
THE EAST COAST...BUT GIVEN LOW AMPLITUDE TROUGHING OF THIS LARGE
FEATURE...A NEARLY WEST SOUTHWESTERLY TO EAST NORTHEASTERLY 100-125
KNOT UPPER JET AT 250 MB TRAVERSES NORTHERN OLD MEXICO TO ACROSS THE
SOUTHERN PLAINS TO THE NORTHEASTERN UNITED STATES. WELL TO THE
SOUTH...A CENTER OF THE DEEP AND WARMEST MID LEVEL RIDGING AT 500 MB
CONTINUES TO SHIFT FARTHER TO THE EAST ACROSS THE WEST CENTRAL
ATLANTIC...BUT A NEW UPPER RIDGE IS BUILDING ACROSS THE WESTERN
CARRIBEAN SEA.

AT THE SURFACE AND IN THE LOWER TO MID LEVELS...SURFACE TO 700
MB...LATEST IR IMAGERY OVERLAID WITH LATEST AVAILABLE MARINE AND
LAND SURFACE OBSERVATIONS AND ANALYSES AS OF 900 AM DETAIL THE
CENTER OF 1040-1045 SURFACE RIDGING EXTENDS FROM COLORADO TO THE
NORTHERN PLAINS. WELL TO THE SOUTH OF THAT...A SURFACE COLD FRONT IS
BARELY MOVING SOUTHWARD AND PRESENTLY EXTENDS FROM THE WESTERN
ATLANTIC TO CROSS FLORIDA NEAR LAKE OKECHOBBE TO THE CENTRAL GULF
AOA 90 WEST 25 NORTH. ACROSS THE TROPICS...THE AXIS OF A LOWER LEVEL
TROUGH IS LOCATED ACROSS THE WESTERN CARIBBEAN SEA. THE 12Z SOUNDING
AT KEY WEST ILLUSTRATED A GENTLE TO MODERATE MOSTLY EAST YET
EXCESSIVELY MOIST SURFACE TO 700 MB FLOW...WITH ADDITIONAL MID LEVEL
MOISTURE BETWEEN 650 AND 550 MB AS WELL.

.CURRENTLY...AS OF 900 AM...LATEST IR IMAGERY AND RADAR SCANS DETECT
PARTLY TO MOSTLY CLOUDY SKIES ACROSS THE ISLANDS AND SURROUNDING
WATERS WITH VERY GOOD COVERAGE OF SCATTERED SHOWERS OF BRIEF
MODERATE TO HEAVY RAINFALL ACCOMPANIED BY LOWER VISIBILITY ACROSS
THE FLORIDA STRAITS...WITH ISOLATED SHOWERS MOVING ACROSS THE KEYS
ISLAND CHAIN. OUTSIDE OF SHOWERS...IT IS AN EXCESSIVELY WARM AND
HUMID MORNING FOR MID DECEMBER ACROSS THE FLORIDA KEYS WITH
TEMPERATURES IN THE UPPER 70S AND DEWPOINTS IN THE LOWER TO MID
70S. THE FEW AVAILABLE C-MAN STATIONS ALONG THE REEF ARE REGISTERING
EAST WINDS AT 10 TO 15 KNOTS...WITH LAST AVAILABLE ASCAT PASS LAST
EVENING ILLUSTRATING EAST WINDS NEAR 15 KNOTS.

.SHORT TERM (REST OF TODAY)...THE COMBINATION OF EXCESSIVE MOISTURE
IN THE LOWER TO MID TROPOSPHERE...WITH LOWER LEVEL CONVERGENCE AHEAD
OF THE NEARLY STALLED FRONTAL BOUNDARY ACROSS THE FLORIDA
PENINSULA...AND A TROUGH OF LOWER PRESSURE MOVING BY TO OUR SOUTH
ACROSS THE WESTERN CARIBBEAN SEA...WILL LEAD TO WELL ABOVE NORMAL
CHANCES FOR SHOWERS ACROSS THE KEYS ISLAND CHAIN AND SURROUNDING
WATERS THROUGH THE BALANCE OF THE DAY. AN UPDATE WAS ALREADY
PERFORMED TO INCREASE RAIN CHANCES TO 50%...GIVEN OVERALL COVERAGE
OF SHOWERS ACROSS THE SERVICE AREA THIS MORNING.

&&

.MARINE...NO HEADLINES OR ADVISORIES EXPECTED FOR THE BALANCE OF THE
DAY...WITH GENTLE TO MODERATE NORTH TO EASTERLY WINDS
EXPECTED...WITH GUSTIER WINDS ANTICIPATED IN AND NEAR ANY SHOWERS.

&&

.AVIATION...
A FEW MVFR ENCOUNTERS ARE POSSIBLE AT THE KEY WEST AND MARATHON
TERMINALS THIS MORNING...WITH VFR CONDITIONS EXPECTED THIS
AFTERNOON. HENCE...A VICINITY SHOWER WILL BE MAINTAINED AND AN
AMENDMENT WILL BE SENT AS NECESSARY. AWAY FROM SHOWERS...MOSTLY EAST
WINDS OF AROUND 10 KNOTS WITH GUSTS NEAR 15 KNOTS.

&&

.CLIMATE...
TODAY IN KEYS WEATHER HISTORY...THE AVERAGE TEMPERATURE IN KEY WEST
SO FAR FOR THE MONTH OF DECEMBER IS 76.4. THIS IS ONLY TWO TENTHS OF
A DEGREE OFF THE RECORD FOR HIGHEST AVERAGE TEMPERATURE DURING THE
MONTH OF DECEMBER SET IN 1931.

&&

&&

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

$$

PUBLIC/MARINE/GRIDS..................FUTTERMAN
AVIATION/CLIMATE/NOWCASTS............APA
UPPER AIR/DATA ACQUISITION...........MPARKE


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