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FXUS62 KKEY 310902
AFDKEY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
502 AM EDT FRI JUL 31 2015

.DISCUSSION...THE CENTER OF A LARGE UPPER-LEVEL ANTICYCLONIC GYRE
REMAINS ACROSS TEXAS. A TROPICAL UPPER TROPOSPHERIC TROUGH (TUTT) IS
MOVING TO THE NORTHWEST INTO THE BAHAMAS. IN BETWEEN THESE TWO
FEATURES...A NEARLY PERMANENT SURFACE TROUGH STRETCHES FROM THE
NORTHERN GULF TO THE CAROLINA COASTS. LOCALLY...THE ZONALLY-DEPRESSED
WESTERN EXTENT OF THE ATLANTIC RIDGE EXTENDS ACROSS THE FLORIDA KEYS
AND AREA COASTAL WATERS. WIND ARE SOUTHERLY AT THE AVAILABLE
OBSERVING STATIONS AND AVERAGE 5 TO 10 KNOTS. OVERNIGHT TEMPERATURES
HAVE NOT FALLEN APPRECIABLY...MID 80S IN MOST LOCATIONS. THE KBYX
RADAR HAS BEEN ECHO FREE...ALTHOUGH THERE IS EVIDENCE OF NORTHWARD
DRIFTING BOUNDARIES. THE ANOMALOUSLY CLOUDY SKIES HAVE CLEARED
RECENTLY...BUT INFRARED SATELLITE IMAGERY REVEALS ADDITIONAL MID-
UPPER LEVEL BANKS UPSTREAM OF THE KEYS.

.SHORT TERM (TODAY THROUGH SUNDAY)...THE AVAILABLE OPINIONS INDICATE
THE SURFACE RIDGE AXIS WILL LIFT NORTH TODAY AND TONIGHT...OPENING
THE KEYS UP TO SOUTHEASTERLY BREEZES. THE LOWER TROPOSPHERIC RIDGE
AXIS (850-600MB) WILL NOT BE AS EXUBERANT TO LIFT NORTH AND WILL
LIKELY REMAIN DRAPED ACROSS THE FLORIDA KEYS. THEREFORE...EXPECT WEAK
CONVECTIVE INHIBITION...LAYERS OF DRY AIR...AND GENTLE TO MODERATE
SURFACE BREEZES. RAIN CHANCES WILL BE SLIGHT (10%) THROUGH
SUNDAY...WITH LOWS IN THE LOWER TO MID 80S AND AFTERNOON HIGHS IN THE
LOWER 90S.

&&

.LONG TERM (SUNDAY NIGHT THROUGH THURSDAY)...THE SURFACE RIDGE AXIS
WILL REMAIN DRAPED ACROSS THE FLORIDA PENINSULA THROUGH
WEDNESDAY...BUT MAY BEGIN TO FRACTURE BY THE END OF THE LONG TERM.
THEREFORE...VERY LITTLE CHANGE TO THE PATTERN FROM THE SHORT THROUGH
THE LONG TERM. HOWEVER...THE PREVIOUSLY MENTIONED TUTT WILL SLIDE
EAST FROM THE BAHAMAS...INCREASING MID-UPPER LEVEL CLOUD COVER SUNDAY
NIGHT AND MONDAY. ADDITIONALLY...THE MULTI-DAY MOS CONSENSUS INDICATES
INCREASED CHANCES FOR PRECIPITATION MONDAY THROUGH TUESDAY. THE
MECHANISM FOR THESE PROBABILITIES REMAINS UNCERTAIN...THEREFORE...NO
CHANGES MADE TO THE FORECAST.

&&

.MARINE...A RIDGE OF HIGH PRESSURE WILL BUILD ACROSS THE FLORIDA
KEYS COASTAL WATERS TODAY...THEN SLOWLY LIFT NORTHWARD TONIGHT
THROUGH TUESDAY NIGHT. EXPECT GENTLE TO MODERATE SOUTHEASTERLY
BREEZES TO PREVAIL.

&&

.AVIATION...VFR CONDITIONS WILL PREVAIL AT THE ISLAND TERMINALS
TODAY. WINDS WILL START OUT LIGHT OUT OF THE SOUTH...STRENGTHENING A
FEW KNOTS AND SHIFTING SOUTHEASTERLY.

&&

.PRELIMINARY POINT TEMPS/POPS...
KEY WEST  90  83  89  83 / 10 10 10 10
MARATHON  93  83  91  83 / 10 10 10 10

&&

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

$$

PUBLIC/MARINE.........CLR
AVIATION/NOWCASTS.....11
DATA COLLECTION.......CHESSER

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