Area Forecast Discussion
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FXUS62 KKEY 190251
AFDKEY

AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
1051 PM EDT FRI APR 18 2014

.DISCUSSION...
.CURRENTLY...
SKIES ARE MOSTLY CLOUDY...WITH AT LEAST A HIGH THIN VEIL OF CIRRUS
COVERING ALL PORTIONS OF THE SERVICE AREA. SHOWERS AND THUNDERSTORMS
HAVE TEMPORARILY WANED OVER SOUTH FLORIDA AND THE SURROUNDING COASTAL
WATERS INCLUDING THE KEYS. TEMPERATURES ARE IN THE UPPER 70S TO NEAR
80 STILL AT THIS HOUR...AND WINDS ARE MOSTLY SOUTH-SOUTHEASTERLY AT
10 TO 15 KNOTS OVER THE COASTAL WATERS. A FEW RANDOM HIGHER GUSTS
HAVE BEEN SEEN NAMELY AT SOMBRERO KEY LIGHT...BUT ARE OF A CURIOUS
NATURE AS PROXIMAL WINDS MEASUREMENT DO NOT REFLECT THE SAME
CONDITIONS. EVENING KEY SOUNDING CAME IN WITH A A VARIABLE MOISTURE
PROFILE...WITH DRY LAYERS AROUND 925 MB AND ABOVE 700 MB. SOME
SIGNIFICANT INSTABILITY WAS SEEN BETWEEN 900MB AND 700 MB...BUT
PROHIBITIVE DRY NEAR THE BASE OF THAT LEVEL IS CAPPING OFF ANY
SIGNIFICANT SHOWER ACTIVITY.

.SHORT TERM...
BOTTOM LINE IS THAT A MEASURABLE AMOUNT OF MOISTENING...AT LEAST IN
THE LOW LEVELS WILL BE REQUIRED IF WIDESPREAD SHOWER AND THUNDERSTORM
ACTIVITY IS TO OCCUR OVERNIGHT. MIMIC PWAT VALUES SHOW A STUBBORN
DRY POCKET ENTRENCHED JUST EAST OF THE AREA...WITH STRUGGLING LOW
LEVEL MOISTURE VALUES OVER THE SOUTHEASTERN GULF. LOW LEVEL WIND
PROFILES LOOK SUBSTANTIALLY MORE FAVORABLE FOR INTENSE THUNDERSTORMS
OVER THE MAINLAND OF FLORIDA AT THIS TIME...BUT A MODEST JET STREAK
ALOFT AND PROGGED MIDLEVEL COOLING WILL BOTH BE CONDUCIVE FOR
THUNDERSTORMS IF SIGNIFICANT MOISTENING CAN OCCUR. NO SIGNIFICANT
CHANGES REQUIRED DURING THIS UPDATE CYCLE OF THE PUBLIC GRIDS OR TEXT
PRODUCTS...EXCEPT FOR THE REMOVAL OF TRANSITIONAL WORDING
OVERNIGHT...AND THE ADDITION OF A HEADLINE FOR A SLIGHT CHANCE OF
SEVERE THUNDERSTORMS MAINLY LATE TONIGHT.

&&

.MARINE...
NO SIGNIFICANT CHANGES REQUIRED DURING THIS UPDATE CYCLE OF THE
MARINE FORECAST. EXPECT THAT A MOMENTARY SURGE IN WINDS AT SOMBRERO
KEY LIGHT WILL PROVE TO BE FLEETING IN NATURE...AND WINDS SHOULD TOP
OUT IN THE AGGREGATE AT AROUND 15 KNOTS. IF SHOWERS AND THUNDERSTORMS
DO DEVELOP HOWEVER...THERE IS A SIGNIFICANT CHANCE THAT THEY WILL
CONTAIN GUSTY WINDS AND LOCALLY ROUGH SEAS. AN ABRUPT SHIFT IN WINDS
TO A WEST-NORTHWESTERLY DIRECTION IS IN STORE FOR THE KEYS BY THE
AFTERNOON ON SATURDAY...WITH CAUTIONARY WORDING A LIKELIHOOD FOR AT
LEAST A FEW ZONES SATURDAY AFTERNOON OR EVENING.

&&

.AVIATION...
VFR CONDITIONS WILL PREVAIL AT EYW AND MTH EARLY TONIGHT. MVFR OR
LOWER CONDITIONS ARE LIKELY AT EYW AND MTH LATE TONIGHT THROUGH
SATURDAY AFTERNOON AHEAD OF AN APPROACHING TROUGH OF LOW PRESSURE.
VFR CONDITIONS WILL PREVAIL AT EYW AND MTH LATE SATURDAY AFTERNOON
INTO SATURDAY EVENING. SUSTAINED SOUTHWEST WINDS OF 10 TO 15 KNOTS
FROM JUST OFF THE SURFACE TO ABOUT 3000 FEET WILL SHIFT TO WEST TO
NORTHWEST SATURDAY MORNING.

&&

.CLIMATE...
ON THIS DATE IN KEYS WEATHER HISTORY...IN 1899...1.37 INCHES OF RAIN
FELL IN KEY WEST. THIS SET THE DAILY RECORD FOR MAXIMUM RAINFALL
MEASURED IN KEY WEST ON APRIL 18TH...A RECORD WHICH STILL STANDS 115
YEARS LATER. RAINFALL RECORDS AT KEY WEST DATE BACK TO 1871.

&&

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

$$

PUBLIC/MARINE.........MSB
AVIATION/NOWCASTS.....BS
DATA COLLECTION.......PARKE

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