Area Forecast Discussion
Issued by NWS Tampa Bay Area, FL

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000
FXUS62 KTBW 070727
AFDTBW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
327 AM EDT THU MAY 7 2015

.SHORT TERM (TODAY - FRIDAY)...
LOW PRESSURE HAS BECOME BETTER DEFINED OVER THE LAST 24 HOURS AND
IS NOW CENTERED ABOUT 200 MILES EAST OF THE FLORIDA/GEORGIA
COASTLINE. MODELS HAVE BEEN HANDLING THIS FEATURE QUITE
WELL...WHICH LENDS INCREASED CONFIDENCE TO THE FORECAST OVER THE
NEXT COUPLE OF DAYS.

WATER VAPOR IMAGERY SHOWS A MID TO UPPER-LEVEL LOW CENTERED TO THE
NORTHEAST OF THE SURFACE LOW WITH A RATHER PRONOUNCED DRY SLOT
WRAPPING AROUND IT. THE DRY SLOT EXTENDS FROM ALABAMA AND GEORGIA
SOUTHEAST ACROSS MOST OF FLORIDA...THEN CURVES CYCLONICALLY EAST...
THEN NORTHEAST INTO THE UPPER-LEVEL LOW.

AT THE SURFACE...THE WIND FIELD ON THE BACK SIDE OF THE LOW ONLY
EXTENDS TO NEAR THE ATLANTIC COAST OF FLORIDA. THE GULF SIDE IS
STILL BEING INFLUENCED BY THE WEAK HIGH PRESSURE CENTER OVER THE
NORTHERN GULF. THIS BASIC PATTERN IS FORECAST TO PERSIST THROUGH
FRIDAY AS THE LOW PRESSURE AREA DEEPENS...BUT LIFTS NORTHWARD AWAY
FROM FLORIDA. THE LOW-LEVEL WIND FLOW WILL BE DIVERGENT ACROSS THE
AREA WITH GENERAL NORTHERLY FLOW DOWN THE SPINE...THEN NORTHEASTERLY
NEAR THE GULF COAST. THE EXCEPTION WILL BE BOTH THIS AFTERNOON AND
AGAIN FRIDAY AFTERNOON WHEN THE SEA BREEZE CIRCULATION EASILY
DOMINATES THE WEAK PRESSURE GRADIENT IN PLACE.

MAY IS TYPICALLY A DRY MONTH FOR OUR REGION...AND THE NEXT COUPLE OF
DAYS WILL BE NO EXCEPTION. THE ABUNDANT MID AND UPPER-LEVEL DRY AIR
COUPLED WITH DRY AIR FILTERING SOUTHWARD IN THE LOW-LEVELS WILL
PROVIDE A HOSTILE ENVIRONMENT FOR SHOWER DEVELOPMENT. SEA BREEZE
CONVERGENCE COULD BE ENOUGH TO IGNITE A FEW SHORT-LIVED SHOWERS IN
EASTERN LEVY AND SUMTER COUNTIES...BUT OVERALL RAIN CHANCES WILL BE
20 PERCENT OR LESS.

TEMPERATURES WILL BE A BIT ABOVE NORMAL FOR THIS TIME OF YEAR WITH
HIGHS EACH DAY BETWEEN 85 AND 90 DEGREES...COOLEST NEAR THE COAST
AND WARMEST WELL INLAND.

.MID/LONG TERM (FRIDAY NIGHT-WEDNESDAY)...
MID-LEVEL CUTOFF LOW WITH ASSOCIATED SURFACE LOW WILL MEANDER
ALONG/OFF THE SOUTHEAST U.S. COAST FRIDAY NIGHT THROUGH SUNDAY THEN
LIFT TO THE NORTHEAST AS A LARGE SCALE TROUGH PUSHES INTO THE
EASTERN STATES. FOR OUR AREA WE WILL SEE A CONTINUATION OF THE DRY
WEST TO NORTHWEST FLOW THROUGH THE WEEKEND. SOME DEEPER MOISTURE
WILL ROTATE AROUND THE SYSTEM AND MOVE ACROSS NORTHEAST FLORIDA
BRUSHING BY THE NATURE COAST AND CENTRAL INTERIOR COUNTIES SATURDAY
AND COULD SEE A COUPLE OF SHOWERS OR STORMS OVER SUMTER AND EASTERN
POLK COUNTIES...BUT WITH THE WEST TO NORTHWEST FLOW THE MAJORITY OF
CONVECTION SHOULD STAY EAST OF OUR AREA. ON SUNDAY THE WEST TO
NORTHWEST FLOW WILL WEAKEN SOME AND WITH JUST ENOUGH MOISTURE
EXPECTED TO BE IN PLACE...PRECIPITABLE WATER NEAR 1.5 INCHES...WE
COULD SEE SOME CONVECTION POP UP ALONG THE SEA BREEZE COLLISION OVER
MAINLY THE INTERIOR AND SOUTHWEST ZONES WHERE THE MOISTURE
WILL BE THE DEEPEST.

FOR THE FIRST HALF OF NEXT WEEK WE WILL HAVE RATHER LIGHT FLOW ALOFT
WITH A SURFACE RIDGE BUILDING WEST ACROSS THE FLORIDA PENINSULA INTO
THE GULF OF MEXICO. MONDAY WILL BE A TRANSITION DAY WITH THE RIDGE
AXIS BUILDING ACROSS CENTRAL FLORIDA WITH A SOUTHEAST FLOW ACROSS
THE SOUTH...SOUTHERLY FLOW CENTRAL AND A SOUTHWEST FLOW ACROSS THE
NATURE COAST. SHOULD BE ENOUGH MOISTURE TO SEE A FEW SHOWERS AND
STORMS WITH THE BEST CHANCES ORIENTED FROM NORTHEAST FLORIDA SOUTH
SOUTHWEST TO SOUTHWEST FLORIDA WHERE THE SEA BREEZES COLLIDE LATE IN
THE DAY. FOR TUESDAY AND WEDNESDAY THE RIDGE AXIS WILL DRIFT NORTH
SOME WITH A MORE EAST TO SOUTHEAST SYNOPTIC FLOW SETTING UP ACROSS
THE ENTIRE AREA WITH THE SEA BREEZES DEVELOPING AND MOVING INLAND
EACH AFTERNOON. SHOULD BE ENOUGH MOISTURE AROUND TO SEE ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS EACH AFTERNOON AND EVENING.

TEMPERATURES WILL REMAIN NEAR TO A COUPLE OF DEGREES ABOVE NORMAL
THROUGH THE PERIOD WITH HIGHS IN THE MID 80S TO LOWER 90S AND
OVERNIGHT LOWS IN THE MID 60S TO LOWER 70S.

&&

.AVIATION...
NO AVIATION CONCERNS NEXT 24 HOURS WITH DRY AIR IN PLACE.

&&

.MARINE...
THE EASTERN GULF WILL BE SANDWICHED BETWEEN LOW PRESSURE DEEPENING
OFF THE SOUTHEAST U.S. COAST AND HIGH PRESSURE OVER THE NORTH-
CENTRAL GULF. WINDS COULD BE QUITE VARIABLE AT TIMES BUT SHOULD
GENERALLY BECOME MORE WESTERLY LATER TODAY AND CONTINUING THROUGH
THE WEEKEND. THE ONSHORE WINDS WILL BE ENHANCED NEAR THE COAST BY
THE SEA BREEZE CIRCULATION EACH AFTERNOON.

THE ATLANTIC LOW IS FORECAST TO LIFT WEAKEN AS IT LIFTS
NORTHEASTWARD AWAY FROM THE SOUTHEASTERN STATES EARLY NEXT WEEK.
HIGH PRESSURE WILL BUILD BACK IN ACROSS THE NORTHERN GULF FROM THE
ATLANTIC BY MONDAY.

&&

.FIRE WEATHER...
SOME CRITICAL RELATIVE HUMIDITIES POSSIBLE THIS AFTERNOON AND
AGAIN FRIDAY AFTERNOON AS DRY AIR FILTERS IN BEHIND THE DEPARTING
LOW PRESSURE AREA OFF THE SOUTHEASTERN U.S. COAST. WINDS ARE
EXPECTED TO REMAIN BELOW 15 MPH AND DURATIONS SHOULD BE SHORTER
THAN 4 HOURS.

&&

.PRELIMINARY POINT TEMPS/POPS...
TPA  87  68  85  70 /   0   0   0   0
FMY  88  68  89  68 /  10   0  10   0
GIF  88  66  88  66 /   0   0  10   0
SRQ  84  67  85  68 /   0   0   0   0
BKV  86  59  87  62 /   0   0   0   0
SPG  86  71  86  71 /   0   0   0   0

&&

.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.

&&

$$

SHORT TERM/AVIATION/MARINE/FIRE WEATHER...JILLSON
LONG TERM/DECISION SUPPORT...CLOSE


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