Area Forecast Discussion
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000
FXUS62 KKEY 281848
AFDKEY

AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
245 PM EDT MON JUL 28 2014

.DISCUSSION...IN THE MID AND UPPER LEVELS...(700-200 MB)...LATEST
AVAILABLE IR IMAGERY OVERLAID WITH SATELLITE IMAGERY AS OF 200 PM
CONTINUES TO DEPICT AN ABNORMALLY AMPLIFIED PATTERN ACROSS THE
EASTERN CONUS...A ROBUST MID AND UPPER TROUGH SITUATED ALONG THE
EASTERN UNITED STATES AND THE BASE OF THE TROUGH LOCATED ACROSS
GEORGIA. TO THE SOUTH OF THAT...THE AXIS OF A DEEP AND WARM MIDDLE
AND UPPER RIDGE REMAINS ORIENTED FROM WEST CENTRAL TEXAS EAST
SOUTHEASTWARD TO CENTRAL FLORIDA AND INTO THE WESTERN
ATLANTIC. ACROSS THE TROPICS...THE NEXT MID AND UPPER TUTT (TROPICAL
UPPER TROPOSPHERIC TROUGH) LOW CENTER IS AMBLING WESTWARD AT 22
NORTH 64 WEST.

AT THE SURFACE AND IN THE LOWER LEVELS...(SURFACE TO 700 MB) LATEST
IR IMAGERY OVERLAID WITH AVAILABLE MARINE AND LAND SURFACE
OBSERVATIONS AND ANALYSIS AS OF 200 PM CONTINUES TO DETAIL AN
ATTENDANT COLD FRONT EXTENDING SOUTHWESTWARD TO ACROSS THE MIDDLE
DIXIE STATES...FROM AN AREA OF LOW PRESSURE LOCATED OVER CENTRAL NEW
ENGLAND. LOCALLY...A WEAK PRESSURE PATTERN REMAINS IN PLACE WITH THE
KEYS IS A COL ZONE.

.CURRENTLY...AS OF 200 PM...SKIES ARE PARTLY CLOUDY ACROSS THE
ISLANDS AND ADJOINING WATERS. TEMPERATURES OUTSIDE OF CONVECTION ARE
IN THE UPPER 80S TO AROUND 90 DEGREES WITH DEWPOINTS IN THE UPPER
70S. C-MAN STATIONS ALONG THE FLORIDA REEF AND SOUTHERN FLORIDA BAY
ARE RECORDING VARIABLE WINDS AT 5 KNOTS OR LESS.

.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT...A UNSEASONABLY DEEP
MID AND UPPER SYNOPTIC SCALE TROUGH WILL REMAIN IN PLACE ACROSS THE
EASTERN CONUS THROUGH THURSDAY AND THURSDAY NIGHT. A WEAK PRESSURE
PATTERN WILL REMAIN IN PLACE...BUT MODEL FORECAST SOUNDINGS DO
MAINTAIN A MORE TYPICAL MOISTURE PROFILE THAN AS OF LATE AS THE
SAHARAN AIR LAYER HAS EXITED FOR NOW...WITH PWAT BETWEEN 1.50 AND
1.75 INCHES THROUGH THE PERIOD. AND GIVEN THE UNUSUALLY DEEP DIVING
SURFACE FRONTAL BOUNDARY ASSOCIATED WITH THE AFOREMENTIONED SURFACE
TROUGH AS IT MOVES SOUTHWARDS...EXPECT LIGHT AND VARIABLE WINDS
TONIGHT TO BECOME WESTERLY TUESDAY THROUGH THURSDAY NIGHT.

THE LOWER TO MID LEVEL PROFILES ARE NOT WELL ALIGNED TO SUPPORT
GOOD MESOSCALE FORCING OVER THE ISLANDS TUESDAY AND TUESDAY
NIGHT...WITH A SLIGHTLY MORE FAVORABLE ALIGNMENT DURING WEDNESDAY
AND WEDNESDAY NIGHT. THEREFORE WILL MAINTAIN ISOLATED SHOWERS AND
THUNDERSTORMS THROUGH WEDNESDAY NIGHT. THEN ON THURSDAY...SLIGHTLY
MORE LOWER LEVEL CONFLUENT FLOW ASSOCIATED WITH THE ARRIVAL OF THE
FRONTAL BOUNDARY...WILL BE ACCOMPANIED BY VERY LIGHT WINDS THROUGH
500 MB...WHICH IS SUPPORTIVE OF LOWER CHANCE POPS...30% FOR THURSDAY
AND THURSDAY EVENING.

.EXTENDED...FRIDAY THROUGH MONDAY...MID AND UPPER RIDGING IS
EXPECTED IN TANDEM WITH A BUILDING SURFACE RIDGE ACROSS SOUTH
FLORIDA. MODEL FORECAST SOUNDINGS ALL INDICATE A DEEPENING ALBEIT
LIGHT MOISTURE PROFILE THOUGH 400 MB. THEREFORE WILL KEEP LOW CHANCE
POPS IN THE GRIDS...WHICH IS TYPICAL AS WE ENTER THE EARLY PART OF
THE CLIMATOLOGICALLY HOTTEST MONTH OF THE YEAR.

&&

.MARINE...GENERALLY LIGHT AND VARIABLE WINDS WILL BECOME LIGHT TO
GENTLE AND MOSTLY WEST TUESDAY THROUGH WEDNESDAY NIGHT...THEN BECOME
LIGHT AND EAST TO SOUTHEASTERLY.

&&

.AVIATION...VFR CONDITIONS WILL PREVAIL...ALTHOUGH A BRIEF SHOWER
MAY OCCUR IN THE VICINITY OF THE KEY WEST AND MARATHON TERMINALS
BEFORE SUNSET. LIGHT AND VARIABLE WINDS...FAVORING OUT OF THE NORTH
OR NORTHWEST AT 5 KNOTS OR LESS...MAY BECOME CALM AT TIMES
OVERNIGHT. A LIGHT WEST WIND 4 TO 7 KNOTS IS EXPECTED TO BEGIN
AROUND SUNRISE TUESDAY.

&&

.CLIMATE...
ON THIS DATE IN KEYS WEATHER HISTORY...IN 1916...7.14 INCHES OF RAIN
FELL IN KEY WEST. THIS SET THE DAILY RECORD FOR MAXIMUM RAINFALL
MEASURED IN KEY WEST ON JULY 28TH...A RECORD WHICH STILL STANDS 98
YEARS LATER. IN ADDITION...THIS IS THE WETTEST DAY EVER RECORDED IN
KEY WEST DURING THE MONTH OF JULY. RAINFALL RECORDS AT KEY WEST DATE
BACK TO 1871.

&&

.PRELIMINARY POINT TEMPS/POPS...
KEY WEST  83  91  82  92  81 / 20  10  10  20  20
MARATHON  81  92  81  93  81 / 20  10  10  20  20
&&

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

&&

$$

PUBLIC/MARINE/FIRE/DIGITAL............FUTTERMAN
AVIATION/NOWCASTS.....................RIZZO
UPPER AIR/DATA ACQUISITION............FLING/VICKERY

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