Area Forecast Discussion
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000
FXUS62 KKEY 041905
AFDKEY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
305 PM EDT MON MAY 4 2015

.DISCUSSION...
.CURRENTLY...
LOCAL RADARS ARE DETECTING ONLY A FEW SHOWERS ACROSS THE ISLAND CHAIN AND
THE ADJACENT WATERS...WITH AN INCREASING AREA OF SHOWERS AND THUNDERSTORMS
ALONG THE ADJACENT WATERS NORTH OF THE ISLAND OF CUBA. SURFACE WISE...A
STRENGTHENING AREA OF HIGH PRESSURE (1029 MB) IS LOCATED JUST OFFSHORE OF
THE NORTH CAROLINA COAST...WITH A TROUGH OF LOW PRESSURE DRAPED FROM
THE EXTREME NORTHWEST CARIBBEAN SEA NORTHEASTWARD INTO THE BAHAMAS.
ACROSS OUR MARINE DISTRICT...NORTHEAST TO EAST WINDS RANGING FROM 18 TO
25 KNOTS AT SAND KEY LIGHT.

.SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...
A DEEPENING AND INTENSIFYING TROUGH EXTENDING FROM THE SOUTHEAST GULF
OF MEXICO INTO THE EXTREME NORTHWEST CARIBBEAN SEA WILL SLOWLY MOVE EASTWARD
OVER THE NEXT COUPLE OF DAYS. THIS WILL INCREASE MOISTURE AND INSTABILITY
TONIGHT THROUGH AT LEAST TUESDAY...BEFORE OUR AREA LIES ON THE LARGE SCALE
DESCENT PERIPHERY OF THE TROUGH TUESDAY NIGHT OR WEDNESDAY. BUT UNTIL
THEN...OUR RAIN CHANCES WILL INCREASE APPRECIABLY TONIGHT AND TUESDAY WITH
LIKELY AND CATEGORICAL POPS. FURTHERMORE...LOCALLY RAINFALL IS LIKELY TUESDAY.
THEREAFTER...DRIER AND MORE STABLE AIR WILL FILTER INTO OUR REGION WITH
DECREASING CHANCE POPS THROUGH WEDNESDAY NIGHT. TEMPERATURES WILL BE BELOW
NORMAL DUE TO CONSIDERABLE CLOUD COVER AND RAINFALL...BEFORE RETURNING
INTO THE LOWER TO MID 80S ON WEDNESDAY.

.LONG TERM (THURSDAY THROUGH SATURDAY)...
MOST MEDIUM RANGE GUIDANCE INDICATES OUR AREA WILL LIE BETWEEN A WESTERN
ATLANTIC RIDGE NOSING DOWN THE SUNSHINE STATE...WHILE AN AREA OF LOW PRESSURE
EAST OF THE FLORIDA COAST MOVES PREDOMINATELY TO NORTH NORTHWESTWARD. WITHOUT
AND DISCERNIBLE LOW LEVEL CONFLUENCE OR UPPER LEVEL ASCENT...WILL INSERT
ISOLATED 20 PERCENT POPS THROUGH THE PERIOD. TEMPERATURES WILL AVERAGE IN
THE MID TO UPPER 80S WITH OVERNIGHT LOWS IN THE MID TO UPPER 70S.

&&

.MARINE...
STRONG NORTHEAST TO EAST WINDS WILL AFFECT OUR OUR ENTIRE MARINE DISTRICT
TONIGHT...HENCE A SMALL CRAFT ADVISORY WILL REMAIN IN EFFECT FOR ALL KEYS COASTAL
WATERS. WINDS WILL SLACKEN TOWARD TUESDAY MORNING...BUT ESPECIALLY BY TUESDAY
AFTERNOON. IN ADDITION...WINDS AND SEAS WILL BE EVEN HIGHER NEAR INCREASING
SHOWERS AND THUNDERSTORMS.

&&

.AVIATION...
LIGHT SHOWERS ARE EXPECTED THROUGH THIS EVENING...BUT
CIGS AND VIS SHOULD REMAIN VFR WITH MINIMAL REDUCTION TO SURFACE
VISIBILITY...AND A FEW CLOUDS AT FL025-030 AND SCATTERED TO BROKEN
CIGS WITH BASES AOA FL050-070. SUSTAINED WINDS FROM JUST OFF THE
SURFACE TO ABOUT 3000 AGL WILL AVERAGE 16 TO 20 KNOTS WITH GUSTS
BETWEEN 25 TO 28 KNOTS FROM 070-090 DEGREES THRU ABOUT 04Z.

&&

.CLIMATE...
ON THIS DATE IN FLORIDA KEYS WEATHER HISTORY...IN 1977...5.33 INCHES
OF RAIN FELL AT KEY WEST INTERNATIONAL AIRPORT. THIS SET THE DAILY
RECORD FOR MAXIMUM RAINFALL MEASURED IN KEY WEST ON MAY 4TH...A
RECORD WHICH STILL STANDS 38 YEARS LATER. RAINFALL RECORDS AT KEY
WEST DATE BACK TO 1871.

&&


.PRELIMINARY POINT TEMPS/POPS...
KEY WEST  73 80 74 82 / 70 80 50 30
MARATHON  73 81 74 84 / 70 80 50 30

&&

.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...SMALL CRAFT ADVISORY FOR GMZ031>035-042>044-052>055-072>075.

&&

$$

PUBLIC/MARINE/FIRE/CLIMATE/DIGITAL...APA
AVIATION.............................DAF

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