Spring Hill, Florida Area

[ROLLTIDE]

000
FXUS62 KTBW 281251 CCA
AFDTBW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
850 AM EDT MON SEP 28 2009

.DISCUSSION...COLD FRONT BOUNDARY DEPICTED IN LATEST MSAS ANALYSIS
AS BASICALLY STALLING BETWEEN SARASOTA AND THE TAMPA BAY AREA. NO
SIGNIFICANT RAIN/THUNDERSTORM ACTIVITY HAS BEEN OBSERVED ACROSS THE
CWA DURING THE MORNING HOURS. SOME ISOLATED CELLS REMAIN WELL
OFFSHORE OVER THE SOUTHERN WATERS...AND NEAR NAPLES.

DAYTIME HEATING WILL HAVE A HARD TIME IN INITIATING CONVECTION WITH
A DRIER AND COOLER AIRMASS ALREADY FILTERING INTO THE NORTHERN
ZONES. BEST CHANCES FOR SHOWERS AND ISOLATED THUNDER WILL BE SOUTH
OF THE TAMPA BAY AREA. 20/30 POPS REMAIN IN PLACE FROM MANATEE DOWN
TO LEE COUNTY FOR THIS AFTERNOON.

CURRENT FORECAST PACKAGE LOOKS GOOD AND NO SIGNIFICANT CHANGES ARE
REQUIRED ATTM.

.PREVIOUS SHORT TERM DISCUSSION...

.SHORT TERM (TODAY - WEDNESDAY)...THE FIRST COLD FRONT OF THE
SEASON WILL SETTLE ACROSS THE TAMPA BAY AREA TODAY...BUT IT WILL
BE VERY SHALLOW AND DIFFICULT TO LOCATE DURING THE DAY DUE TO
MIXING. THIS MAKES THE PRECIPITATION FORECAST A LITTLE MORE
DIFFICULT...BUT WITH SO MUCH DRY AIR ALREADY WELL ESTABLISHED IN
THE MID LEVELS OF THE ATMOSPHERE...FEEL BEST RAIN CHANCES WILL BE
ALONG THE WEAK CONVERGENCE BOUNDARY SOUTH OF THE FRONT...AND
MAINLY OVER LAND WITH HEATING TODAY. THIS WOULD FAVOR CHARLOTTE
AND LEE COUNTIES...SO WILL FORECAST SCATTERED THUNDERSTORMS THERE.
NORTH OF THERE...JUST ENOUGH MOISTURE IN THE LOWER LEVELS FOR SOME
ISOLATED SHOWERS OR STORMS RIGHT ALONG THE BOUNDARY...THEN LESS
THAN 20 PERCENT RAIN CHANCES FOR TAMPA BAY NORTHWARD. IT WILL
STILL BE ON THE WARM SIDE...WITH HIGHS STILL AROUND 90 DEGREES
AWAY FROM THE COAST.

THE FRONT LOSES ITS IDENTITY TONIGHT AS A SECOND MORE SIGNIFICANT
COLD FRONT APPROACHES FROM THE NORTH. THE FIRST FRONTAL BOUNDARY
WILL HAVE STOLEN MUCH OF THE MOISTURE...SO ONLY A FEW SPRINKLES
ARE EXPECTED AS THE FRONT MAKES ITS WAY SOUTHWARD ON TUESDAY.
OVERALL CHANCES FOR MEASURABLE RAIN WILL BE LESS THAN 20
PERCENT...BUT THERE IS A FAIRLY GOOD CHANCE THAT MANY AREAS WILL
HAVE A TRACE OF RAIN. THE NUMERICAL GUIDANCE IS STRUGGLING WITH
THIS SCENARIO...BUT BASED ON THE VERTICAL MOISTURE PROFILE...WILL
LEAVE SHOWERS OUT OF THE FORECAST FOR NOW. THE MOST SIGNIFICANT
FEATURE WILL BE THE TEMPERATURES...WHICH WILL FALL INTO THE MID
60S FOR THE NATURE COAST...AND EVEN SOME UPPER 60S OVER OUR
INTERIOR CENTRAL ZONES. THE COAST WILL CONTINUE TO REMAIN IN THE
70S. HIGHS ON TUESDAY WILL DEPEND ON HOW MUCH CLOUD COVER WE GET
AHEAD OF THE NEXT COLD FRONT...BUT COULD EASILY REACH 90 DEGREES
OR SO...ESPECIALLY FROM TAMPA BAY SOUTH.

IT WILL FEEL NOTICEABLE COOLER DURING THE MORNING COMMUTE ON
WEDNESDAY AS WE START THE DAY IN THE MIDDLE 50S OVER THE NATURE
COAST...TO THE MID 60S AWAY FROM THE COAST ELSEWHERE.

WEDNESDAY WILL FEATURE LOTS OF SUNSHINE AND COMFORTABLY WARM
TEMPERATURES. IT WILL BE IN THE LOWER 80S ALONG THE NATURE
COAST...BUT STILL REACH THE MID 80S AROUND THE BAY AND EVEN SOME
UPPER 80S OVER THE INTERIOR SOUTH.

&&

.AVIATION...VFR CONDITIONS EXPECTED FOR THE NEXT 24 HOURS. COULD SEE
SOME LIGHT RAIN DEVELOP OVER FMY AND RSW THIS AFTERNOON AS A COLD
FRONT DIPS SOUTH...BUT OTHERWISE TERMINALS WILL REMAIN DRY. LESS
CLOUD COVER WILL BE SEEN FOR TONIGHT AND TOMORROW WITH DRIER AIR
MOVING IN BEHIND THE FRONT.

&&

.MARINE...NO HIGHLIGHTS EXPECTED FOR THE REST OF TODAY.
TONIGHT...WEST/SOUTHWESTERLY WINDS MAY INCREASE INTO THE 10-15 KNOTS
RANGE AS A SECONDARY FRONTAL BOUNDARY APPROACHES FROM THE NORTH.
THEN DIRECTIONS SHIFT TO A MORE NORTHWESTERLY FLOW ON TUESDAY BEHIND
THE FRONT. IN GENERAL...WINDS AND SEAS SHOULD REMAIN BELOW HIGHLIGHT
CRITERIA THROUGH THE FORECAST PERIOD.

&&

.FIRE WEATHER...NO PROBLEMS EXPECTED TODAY. HUMIDITIES WILL START
DECREASING ON TUESDAY...AND A MUCH DRIER AIRMASS MAY BRING DEWPOINTS
DROPPING FASTER THAN MODELS ARE SHOWING AT THIS TIME. THE SITUATION
WILL BE CLOSELY MONITORED IN CASE A FIRE WEATHER WATCH BECOMES
NECESSARY FOR WEDNESDAY AFTERNOON.

&&

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