FXUS62 KTBW 090817
AFDTBW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
317 AM EST WED DEC 9 2009
.SHORT TERM (TODAY - FRIDAY)...THE GFS AND ECMWF REMAIN FAIRLY
CONSISTENT WITH THE HANDLING OF SYNOPTIC SCALE FEATURES DURING
THE SHORT TERM PERIOD SO WILL CONTINUE TO USE A BLEND. A DEEPENING
STORM SYSTEM OVER MID MISSISSIPPI VALLEY IS SUPPORTING AN INCREASING
SOUTHERLY WIND FLOW ACROSS THE FORECAST AREA EARLY THIS MORNING
ALONG WITH AREAS OF LOW STRATUS. WITH THE INCREASE IN WINDS...FOG
SHOULD NOT BE A PREVALENT AS YESTERDAY MORNING BUT WILL LEAVE PATCHY
WORDING IN TO ACCOUNT FOR SOME FORMATION WITH BEST CHANCES LIKELY
TO BE ACROSS CENTRAL AND SOUTHERN ZONES WHERE WINDS ARE STILL RUNNING
10 KNOTS OR LESS.
AS FOR THE REST OF TODAY AFOREMENTIONED STORM SYSTEM WILL MOVE INTO EASTERN
GREAT LAKES REGION WITH ITS TRAILING COLD FRONT MOVING THROUGH THE
PANHANDLE. AN INCREASING SOUTH TO SOUTHWEST WIND FLOW AHEAD OF THIS FRONT
WILL MAKE FOR A BREEZY WARM AND HUMID DAY ACROSS THE FORECAST AREA WITH
INCREASING CHANCES FOR SHOWERS AND EVEN A FEW STORMS (HIGHEST POPS 40
TO 50%) OVER THE NATURE COAST DURING THE AFTERNOON WITH SLIGHT CHANCE
TO CHANCE CATEGORY POPS (30-20%) CENTRAL AND SOUTH.
TONIGHT THROUGH THURSDAY THE COLD FRONT WILL MOVE INTO WEST CENTRAL
FLORIDA. THE GFS AND ECMWF CONTINUE TO SHOW AMPLE MOISTURE AND LIFT
ALONG AND AHEAD OF THIS BOUNDARY SO WILL MAINTAIN CHANCE CATEGORY POPS
ALL ZONES WITH AREAS OF LIGHT RAIN OR SHOWERS EXPECTED UNDER CLOUDY
SKIES. WITH GOOD CHANCES FOR RAIN AND COOLER AIR MOVING INTO THE REGION
THURSDAY IS SHAPING UP TO BE A RAW AND DISMAL DAY.
DURING THURSDAY NIGHT THE FRONT WILL STALL OUT OVER THE SOUTH-CENTRAL
PENINSULA AS SURFACE HIGH PRESSURE TO THE NORTH BRIDGES ACROSS IT.
DRIER AND COOLER AIR ADVECTING IN FROM THE NORTH IN THE WAKE OF THE
FRONT WILL BRING AN END TO THE RAIN ACROSS NORTHERN AND CENTRAL ZONES
WITH SLIGHT CHANCES (POPS 20%) CONTINUING FAR SOUTH. ON FRIDAY THE STALLED
FRONT WILL BEGIN TO LIFT BACK TO THE NORTH AS A WARM FRONT DURING THE
DAY AS SURFACE LOW PRESSURE DEVELOPS OVER THE WESTERN GULF WITH LOW
LEVEL FLOW VEERING INTO THE SOUTHEAST. AMPLE LOW LEVEL MOISTURE WITHIN
THE DEVELOPING WARM SECTOR WILL LEAD TO CONSIDERABLE CLOUDINESS AND
SOME ISOLATED SHOWERS DURING THE AFTERNOON AND WILL DEPICT 20 PERCENT
POPS IN THE GRIDS. TEMPERATURES WILL REMAIN WELL ABOVE NORMAL TODAY
THROUGH FRIDAY ACROSS FAR SOUTHERN ZONES...WHILE A COOL DOWN WITH
BELOW NORMAL TEMPERATURES IS EXPECTED ACROSS CENTRAL AND NORTHERN
ZONES THURSDAY INTO FRIDAY AS COOLER AIR ADVECTS INTO THE REGION
IN THE WAKE OF THE FRONT. A SLOWER MOVEMENT OF THE FRONT DEPICTED
BY THE NAM COMPARED TO THE GFS LEADS TO BIG DIFFERENCES IN MAX/MIN
TEMPERATURES DURING THURS/FRI. THE GFS HAS BEEN MORE CONSISTENT
WITH THE MOVEMENT OF THE FRONT OVER THE PAST SEVERAL DAYS SO WILL
LEAN IN THE DIRECTION...WITH MAX TEMPERATURES ON THURSDAY LIKELY
TO OCCUR EARLY IN THE MORNING WITH TEMPERATURES HOLDING STEADY OR
FALLING THEREAFTER AS COLD AIR ADVECTION TAKES HOLD.
.LONG TERM (FRIDAY NIGHT - TUESDAY)...WSW FLOW WILL REMAIN AT THE
UPPER LEVELS THROUGH THE PERIOD WITH DISTURBANCES MOVING THROUGH THE
FLOW OVER THE AREA THROUGH THE PERIOD. AT THE SURFACE...A REMNANT
BOUNDARY WILL BE LIFTING NORTH OVER THE AREA THROUGH SATURDAY. WEAK
LOW PRESSURE WILL DEVELOP ALONG THE BOUNDARY ACROSS NORTHERN FL
SATURDAY NIGHT AND THEN THE COLD FRONT WITH THAT SYSTEM WILL MOVE
INTO THE AREA SUNDAY AND STALL ACROSS SOUTHERN ZONES SUNDAY NIGHT.
HIGH PRESSURE WILL BUILD INTO THE REGION TO THE NORTH THROUGH EARLY
TUESDAY WITH ANOTHER LOW PRESSURE SYSTEM PUSHING INTO NORTHERN FL
TUESDAY AFTERNOON. GENERALLY 20-40 PERCENT RAIN CHANCES WILL BE IN
PLACE ACROSS THE AREA THROUGH THE PERIOD WITH THE BOUNDARIES
MEANDERING OVER THE AREA. TEMPS WILL REMAIN ABOVE NORMAL THROUGH THE
PERIOD.
&&
.AVIATION...PATCHY MVFR FOG IS DEVELOPING ACROSS THE TERMINALS THIS
MORNING WITH MVFR TO IFR CIGS IN PLACE. THIS SHOULD CONTINUE THROUGH
AROUND 14Z TODAY. CEILINGS SHOULD THEN LIFT TO VFR THROUGH THE LATE
MORNING AND AFTERNOON AS WINDS BECOME A BIT GUSTY. THERE IS ALSO A
SLIGHT CHANCE OF RAIN ACROSS THE NORTHERN TERMINALS FOR THIS
AFTERNOON...BUT WITH LOW CHANCES HAVE LEFT OUT OF THE TAFS FOR NOW.
MVFR/IFR CIGS SHOULD THEN RETURN ACROSS THE TERMINALS AFTER
MIDNIGHT.
&&
.MARINE...SOUTH TO SOUTHWEST WINDS WILL INCREASE INTO THE 15-20 KNOT
RANGE ACROSS THE NORTHERN AND CENTRAL WATERS LATER THIS MORNING AHEAD
OF A COLD FRONT MOVING THROUGH THE PANHANDLE. TONIGHT WINDS WILL SHIFT
INTO THE NORTH THEN NORTHEAST DURING THURSDAY AND THURSDAY NIGHT WITH
SPEEDS LIKELY REACHING SMALL CRAFT CRITERIA FOR A SHORT PERIOD AS THE
FRONT SINKS SOUTH INTO THE SOUTH-CENTRAL PENINSULA WHERE IT WILL STALL
OUT BY EARLY FRIDAY. DURING FRIDAY THROUGH SATURDAY WINDS WILL REMAIN
ELEVATED NEAR EXERCISE CAUTION LEVELS AS THEY QUICKLY VEER FROM EAST
TO SOUTHERLY AS SURFACE LOW PRESSURE DEVELOPS AND MOVES ALONG THE FRONT
ACROSS THE NORTHERN GULF COAST SATURDAY NIGHT INTO SUNDAY. WITH WINDS
AND SEAS EXPECTED TO INCREASE WILL EXPAND EXERCISE CAUTION HEADLINES
SOUTH INTO THE CENTRAL WATERS FROM ENGLEWOOD NORTH TO SUWANNEE RIVER
FOR TODAY IN THE 430 AM COAST PACKAGE AND WILL ALSO HIGHLIGHT SMALL
CRAFT ADVISORY MAY BE REQUIRED NORTHERN AND CENTRAL WATERS ON THURSDAY
AS THE FRONT MOVES INTO THE REGION.
&&
.FIRE WEATHER...AMPLE LOW LEVEL MOISTURE WILL KEEP HUMIDITY VALUES
WELL ABOVE CRITICAL LEVELS THROUGH THE END OF THE WEEK WITH NO FIRE
WEATHER ISSUES EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 79 66 70 51 / 30 40 50 20
FMY 84 71 81 58 / 10 20 40 20
GIF 84 66 70 49 / 30 40 50 20
SRQ 80 68 75 53 / 30 40 50 20
BKV 81 59 67 44 / 40 40 50 20
SPG 80 68 70 54 / 30 40 50 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SHORT TERM/MARINE/FIRE WEATHER...57/MCMICHAEL
LONG TERM/AVIATION...24/COLSON
