Area Forecast Discussion
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000
FXUS62 KKEY 011856
AFDKEY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
256 PM EDT SAT AUG 1 2015

.DISCUSSION...
.CURRENTLY...
FROM THE SATELLITE VIEW WE CAN SEE THE TROPICAL UPPER TROPOSPHERIC
TROUGH (TUTT) COMING UNDER THE INFLUENCE OF THE MID LEVEL TROUGH OFF
THE EASTERN SEABOARD. THE TROUGH EXTENDS ACROSS NORTH FLORIDA AND
THE NORTHERN GULF OF MEXICO TO THE TEXAS COAST. THE TUTT CELL IS
BEING DISTURBED IN THE NORTHWEST QUADRANT AS THE TROUGH IMPINGES ON
IT. PLENTY OF MID LEVEL MOISTURE AND BY VISUAL OBSERVATION THE
DISTINCT APPEARANCE OF A SAHARAN AIR LAYER (DUST) IS MOVING ACROSS
THE KEYS AREA. WINDS ARE SOUTHEAST TO SOUTH AROUND 15 KNOTS FROM KEY
WEST EASTWARD...NEAR 10 KNOTS FROM KEY WEST WESTWARD AND TO THE NORTH
OVER THE GULF WATERS. THE KEY WEST AND MARATHON TERMINALS ARE BLOWING
NEAR 10 KNOTS.

.FORECAST...
MID LEVEL MOISTURE REMAINS IN PLACE OVER THE KEYS AREA THIS
AFTERNOON...AND AFTER VISUAL INSPECTION OF THE SKY WE CAN SEE THE SAL
LAYER IS PROMINENT OVER THE KEYS AS WELL. WITH THE SAL AND DRY AIR IN
THE LOW LEVELS OF THE BOUNDARY LAYER. THE TUTT CELL INTERACTION WITH
THE TROUGH MENTIONED ABOVE WILL CONTINUE TO BROADEN...WHILE DRIFTING
SOUTHWARD THROUGH SUNDAY. THE MODERATE WINDS FROM KEY WEST EAST MAY
BE AN ARTIFACT OF THE TROUGH AND TUTT MIXING WINDS DOWN THROUGH THE
BOUNDARY LAYER. STILL...EXPECT GENTLE TO MODERATE BREEZES TO PEAK AND
LULL THROUGH SUNDAY WITH THE HIGHEST WINDS LIKELY OVERNIGHT.

THE RIDGE TO OUR NORTH WILL REMAIN NEARBY WITH SOME PERTURBATIONS I
THE PRESSURE GRADIENT CAUSED BY DAYTIME HEATING OVER THE MAINLAND AND
WEAK WAVES IN THE PRESSURE GRADIENT. MODEL SOUNDING DATA WOULD
SUGGEST A BETTER WIND PROFILE FOR ISLAND CLOUD LINES BEGINNING
MONDAY...BUT PLENTY OF DRY AIR THROUGH THE MID LAYERS MAY KEEP THE
VERTICAL DEVELOPMENT TO A MINIMUM...AND RAIN CHANCES IN THE SLIGHT
CATEGORY. SO NO CHANGES IN THE FORECAST ARE EXPECTED DURING THIS
CYCLE.

&&

.MARINE...
AN AREA OF HIGH PRESSURE OVER THE WESTERN ATLANTIC WILL CONTINUE TO
LIFT TO THE NORTH WITH PEAK AND LULLS IN THE WINDS DUE TO DAYTIME
HEATING OVER SOUTH FLORIDA AND WEAK PERTURBATIONS IN THE PRESSURE
FIELD DISTURBING THE FLOW. THIS RIDGE WILL REMAIN JUST NORTH OF THE
KEYS THROUGH MID WEEK. NO ADVISORY AND CAUTIONARY STATEMENTS ARE
EXPECTED THROUGH MID WEEK.

&&

.AVIATION...
VFR CONDITIONS WILL PREVAIL MOST OF TODAY AT THE KEY WEST AND
MARATHON TERMINALS...WITH THE EXCEPTION OF BRIEF PERIODS OF MVFR CIGS
DUE TO CLOUDS MOVING SOUTH ACROSS THE AREA. WINDS OF 5 TO 10 KNOTS
GENERALLY FROM THE SOUTHEAST WILL BE OBSERVED WITH A BRIEF SHIFT FROM
THE EAST SOUTHEAST THIS EVENING...VEERING AGAIN FROM THE SOUTHEAST IN
THE EARLY MORNING HOURS.


&&

.CLIMATE...
AS OF 900 AM TODAY...THE MINIMUM TEMPERATURE AT KEY WEST WAS 85
DEGREES. IF THE TEMPERATURE DOES NOT GO BELOW THAT BEFORE THE END OF
THE DAY...IT WILL TIED THE DAILY RECORD WARM LOW SET BACK LAST TIME
IN 2014.

&&

.PRELIMINARY POINT TEMPS/POPS...
KEY WEST  83  90  82  91 / 10 10 10 20
MARATHON  83  93  82  93 / 10 10 10 20

&&

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

$$

PUBLIC/MARINE.................BWC
AVIATION/NOWCASTS/CLIMATE.....KN
DATA COLLECTION...............CHESSER/FLING

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