Area Forecast Discussion
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000
FXUS62 KKEY 021327
AFDKEY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
927 AM EDT SUN AUG 2 2015

.DISCUSSION...
.CURRENTLY...
SIMILAR TO THE PAST FEW DAYS WE HAVE THE REMNANT TROUGH SITTING
ACROSS THE NORTHERN GULF OF MEXICO AND CENTRAL FLORIDA WITH SOME
LOCALIZED LOW TO MID LEVEL VORTICITY JUST WEST OF THE TAMPA BAY AREA.
A TUTT CELL IS STILL ATTEMPTING TO SLIDE TO THE WEST OUT OF THE
BAHAMAS...AND IS TRAPPED BY AN MID LATITUDE TROUGH MOVING ACROSS THE
EASTERN UNITED STATES...AND A STRONG RIDGE AXIS TO ITS NORTH. RECENT
ANALYSIS FROM CIMSS HAS LOW TO MID LEVEL VORTICITY STACKED ALONG THE
SOUTHEASTERN BAHAMAS THIS MORNING. THE MORNING UPPER AIR DATA SHOW A
WEAKER VERTICAL WIND PROFILE AND MODEST MOISTURE. MARINE WINDS ARE
OUT OF THE SOUTHEAST TO SOUTH NEAR 10 KNOTS AT THE MARINE REPORTING
STATIONS ALONG THE ISLAND CHAIN...WITH 5 TO 10 KNOTS FROM SMITH AND
PULASKI SHOALS...AND NEAR 5 KNOTS AT THE ISLAND TERMINALS.

.FORECAST...
THE SOUNDING WOULD SUGGEST STEEP LAPSE RATES IN THE LOWER TO MID
LEVELS WITH LIMITED MOISTURE THROUGH THE VERTICAL PROFILE...1.65
INCHES OF PWAT...AND VERY LIGHT WINDS THROUGH THE LOWER BOUNDARY
LAYER. WINDS ARE DECREASING AND WE HAVE LINGERING BOUNDARIES FLOATING
AROUND THE ISLAND CHAIN. AS WINDS DECREASE WE WILL SEE SOME LOCALIZED
LOW LEVEL CONVERGENCE SPAWNING CLOUD STREETS AND SOME SHOWERS. THE
-10 CELSIUS LEVEL IS AROUND 21 K FEET AND AS EXPECTED ANY SHOWERS
THAT PRODUCE 40 DBZ ABOVE THIS LEVEL WILL LIKELY INCLUDE LIGHTNING.
THE TUTT CELL WILL FIGHT THROUGH THE TROUGH TO THE NORTH AND CONTINUE
TO DRIFT TO THE WEST WHILE THE RIDGE TO THE NORTH NUDGES THE TUTT TO
THE SOUTH THROUGH MONDAY NIGHT. LOW LEVEL VORTICITY ASSOCIATED WITH
THE TUTT WILL MOVE THROUGH THE KEYS AREA TUESDAY...PROVIDING A
BETTER LIFTING MECHANISM...HENCE A SLIGHTLY BETTER CHANCE OF SHOWERS
AND THUNDERSTORMS TUESDAY.

WE WILL HAVE A SAHARAN DUST EVENT RIDING ON THE BACK SIDE OF THE
TUTT WHICH IS LIKELY TO ARRIVE WEDNESDAY NIGHT WHILE THE ATLANTIC
RIDGE BUILDS BACK INTO THE EASTERN GULF OF MEXICO. THE PRESSURE
GRADIENT WILL STRENGTHEN A BIT AND TURN WINDS TO THE EAST. THE NORMAL
SUMMER TIME PERTURBATIONS TO THE PRESSURE GRADIENT WILL BE ENFORCED
BY DAYTIME HEATING ON THE MAINLAND...AND WEAK DISTURBANCES IN THE
PRESSURE FIELD CAUSING PEAKS AND LULLS IN THESE EASTERLY BREEZES.
WHILE THE HIGH PRESSURE REBUILDS...THE NEXT DUST EVENT ARRIVES AND
WILL KEEP RAIN IN THE SLIGHT CHANCE CATEGORY THURSDAY THROUGH THE
WEEKEND.

&&

.MARINE...
HIGH PRESSURE NEAR THE FLORIDA KEYS WILL SLIDE TO THE NORTH THROUGH
MONDAY NIGHT WITH AN INCREASING PRESSURE GRADIENT...WHICH WILL
INCREASE BREEZES TO GENTLE TO MODERATE TUESDAY THROUGH THURSDAY
NIGHT. THE CURRENT GULF STREAM ANALYSIS PRODUCT IS FIVE DAYS OLD.
THE PERSISTENT CLOUD COVER AND LACK OF SIGNIFICANT TEMPERATURE
GRADIENT HAS DELAYED THE PRODUCTION OF A MORE CURRENT ANALYSIS.

&&

.AVIATION...
VFR CONDITIONS WILL PREVAIL TODAY AT THE KEY WEST AND MARATHON
TERMINALS. WINDS OF 5 TO 10 KNOTS GENERALLY FROM THE SOUTH WILL BE
OBSERVED.

&&

.CLIMATE...
AS OF 900 AM TODAY...THE MINIMUM TEMPERATURE AT KEY WEST WAS 84
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 IN 2010.

&&

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

$$

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

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