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000
FXUS62 KKEY 072112
AFDKEY

AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
412 PM EST FRI MAR 7 2014

.DISCUSSION...
CURRENT WEATHER SUMMARY -- BREEZY AND MILD WEATHER HAS PREVAILED
TODAY ACROSS THE FLORIDA KEYS. THE INCOMING AIR MASS OF CONTINENTAL
ORIGIN HAS TRAVELED SEVERAL HUNDRED MILES OVER THE GULF OF
MEXICO IN A BROAD CYCLONIC ARC...AND CONSEQUENTLY HAS MODIFIED
SIGNIFICANTLY...MAKING IT FEEL VERY PLEASANT IN KEYS COMMUNITIES.
CURRENTLY...AIR TEMPERATURES GENERALLY ARE IN THE MID 70S WITH
DEWPOINTS NEAR 60F...WHILE WEST TO NORTHWEST BREEZES ARE BLOWING A
STEADY 15-20 MPH. THE KEY WEST DOPPLER RADAR HAS BEEN REPAIRED... AND
IS OPERATIONAL ONCE AGAIN...SHOWING NO PRECIPITATION ECHOES OVER THE
SERVICE AREA AT PRESENT. BOTH SATELLITE AND SURFACE OBSERVATIONS
REVEAL SCATTERED SHALLOW CUMULUS AND STRATOCUMULUS CLOUDS TRAVERSING
THE SERVICE AREA. A SURFACE LOW PRESSURE AREA IS MOVING
NORTHEASTWARD AND INTENSIFYING SLOWLY JUST OFF THE OUTER BANKS OF
NORTH CAROLINA THIS AFTERNOON. TWO LARGE-SCALE TROUGHS HAVE BEEN
ASSOCIATED WITH THIS LOW PRESSURE AREA DURING THE LAST 24 HOURS. ONE
TROUGH MOVED THROUGH THE KEYS OVERNIGHT AND EARLY THIS MORNING...AND
WAS ACCOMPANIED BY A NARROW LINE OF SHOWERS AND A WIND SHIFT FROM
SOUTHWEST TO NORTHWEST. A SECONDARY TROUGH APPEARS TO BE PIVOTING
SOUTHWARD OVER SOUTHERN FLORIDA AND THE EASTERN GULF OF MEXICO. THIS
TROUGH IS ASSOCIATED WITH A TIGHTER BAROCLINIC ZONE AS WELL AS A
WIND SHIFT FROM WEST-NORTHWEST TO NORTHWEST. LOCAL COOLING AND
DRYING WILL ACCELERATE AFTER THIS TROUGH ARRIVES IN A FEW HOURS.

FORECAST HIGHLIGHTS FOR TONIGHT THROUGH TUESDAY -- THE PROGRESSIVE
SPLIT-FLOW SYNOPTIC-SCALE REGIME WILL PERSIST FOR THE NEXT SEVERAL
DAYS. A SOUTHERN-STREAM CUT-OFF CYCLONE CURRENTLY CENTERED ATOP THE
SURFACE LOW OVER COASTAL NORTH CAROLINA WILL EJECT NORTHEASTWARD
TONIGHT AND SATURDAY. IN ITS WAKE...A BROAD...SLOWLY-EVOLVING SHORT-
WAVE RIDGE WILL DEVELOP AND PERSIST OVER MOST OF THE GULF BASIN AND
FLORIDA PENINSULA. BENEATH THIS RIDGE AND BROAD BELT OF WESTERLIES...
A WEAK CONTINENTAL HIGH PRESSURE CELL WILL TRANSLATE SLOWLY TOWARD
THE EAST AND SOUTHEAST. THIS EVOLUTION WILL CAUSE NEAR-SURFACE WINDS
TO VEER FROM TONIGHT THROUGH TUESDAY NIGHT...WITH GRADUAL WARMING AND
MOISTENING AFTER A COOL NIGHT TONIGHT. A DEEP LAYER OF DRY AND STABLE
AIR ASSOCIATED WITH LARGE-SCALE RIDGING AND CONTINENTAL AIR AT LOW
LEVELS WILL KEEP RAIN CHANCES NIL THROUGH TUESDAY.

FORECAST HIGHLIGHTS FOR WEDNESDAY THROUGH FRIDAY -- NUMERICAL WEATHER
PREDICTION MODELS SUGGEST MUCH GREATER UNCERTAINTY FOR THIS PERIOD AS
YET ANOTHER SOUTHERN-STREAM SHORT-WAVE TROUGH AND ITS ATTENDANT WAVE
CYCLONE AND SURFACE FRONT ARE PROJECTED TO EVOLVE IN VARYING PATHS...
STRUCTURES...AND INTENSITIES ACROSS THE SOUTHEASTERN UNITED STATES
AND GULF BASIN. OUR FORECASTS ARE CLOSE TO A NUMERICAL MODEL
CONSENSUS ON WEDNESDAY...TRENDING TOWARD CLIMATOLOGY BY FRIDAY. THIS
STRATEGY YIELDS A FORECAST OF NEAR-AVERAGE TEMPERATURES...SLIGHT
SHOWER CHANCES...AND A VEERING WIND WITH SLIGHTLY ABOVE AVERAGE WIND
SPEEDS.
&&

.MARINE...
A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR ALL ZONES SURROUNDING
THE FLORIDA KEYS. WEST TO NORTHWEST WINDS NEAR 20 KNOTS WILL TURN
NORTHWEST THIS EVENING...THEN NORTH OVERNIGHT...WITH WIND SPEEDS
DROPPING AFTER MIDNIGHT. A WELL-DEVELOPED WIND SEA WILL BE MIXED IN
WITH WESTERLY SWELL TRAINS FROM THE OPEN GULF OF MEXICO. SEAS SHOULD
START SUBSIDING AFTER MIDNIGHT AS WELL. RESIDUAL NORTH SWELLS FROM
THE ATLANTIC MAY DEVELOP IN THE STRAITS OFF THE UPPER KEYS BY
SATURDAY MORNING...AS OUR NEARSHORE WAVE PREDICTION SYSTEM SUGGESTS.
&&

.AVIATION...
VFR CONDITIONS ARE EXPECTED AT KEY WEST INTERNATIONAL AND MARATHON
AIRPORTS THROUGH THE FORECAST PERIOD. NORTHWEST WINDS 5 TO 10 KNOTS
WILL GRADUALLY SHIFT TO NORTH NORTHEAST.
&&

.PRELIMINARY POINT TEMPS/POPS...
KEY WEST  63  73  65  78 / -  -  -  -
MARATHON  62  73  65  78 / -  -  -  -
&&

.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...SMALL CRAFT ADVISORY IN EFFECT FOR GMZ031-GMZ032-GMZ033-
     GMZ034-GMZ035-GMZ042-GMZ043-GMZ044-GMZ052-GMZ053-GMZ054-
     GMZ055-GMZ072-GMZ073-GMZ074-GMZ075.
&&

$$

PUBLIC/MARINE.........KASPER
AVIATION/NOWCASTS.....JOHNSON
DATA COLLECTION.......PARKE

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