FXUS62 KTBW 251824
AFDTBW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
124 PM EST WED NOV 25 2009

.SHORT TERM (TONIGHT THROUGH FRIDAY)...LATEST MSAS ANALYSIS SHOWS
THE STATIONARY BOUNDARY LINGERING OVER THE STATE WITH A WEAK
SURFACE LOW EAST OF THE PENINSULA AND A ANOTHER WEAK SURFACE LOW
DEVELOPING OVER THE INTERIOR PENINSULA. PLENTY OF SHOWERS REMAIN
IN THE AREA MAINLY BELOW THE I 4 CORRIDOR. NORTHWEST OF THE
STATIONARY BOUNDARY...A COLD FRONT IS BEGINNING TO PUSH INTO THE
PANHANDLE AND SHOULD SWEEP SOUTH OF THE AREA BY TOMORROW
AFTERNOON.

FOR THE REST OF THE TODAY...SHOWERS WILL PERSIST THROUGH THE
EVENING BEFORE TAPERING OFF NORTH TO SOUTH. THE NORTHWARD
MOVEMENT OF THE OF THE SHOWERS EARLIER TODAY HAS NOW SHIFTED TO A
MORE WNW MOVEMENT AS THE COLD FRONT EDGES INTO THE PANHANDLE.
THEREFORE...SHOWER ACTIVITY WILL MAINLY BE LIMITED TO AREAS SOUTH
OF I 4 AND TAMPA BAY. 

FOR TURKEY DAY AND FRIDAY...SHOWERS WILL PUSH SOUTH OF THE REGION
BY EARLY OR MID THURSDAY MORNING AS HIGH PRESSURE BUILDS IN FROM THE
NORTHWEST. COLD AIR ADVECT ION WILL TAKE PLACE THROUGH FRIDAY AS A
MID LEVEL RIDGE BUILDS IN FROM THE NORTHWEST AND A MID LEVEL
TROUGH MOVES OFF THE ATLANTIC COAST. COOLER AND DRIER CONDITIONS
WITH MINIMAL RAIN CHANCES CAN BE EXPECTED THROUGH THE END OF THE
SHORT TERM.

TEMP WISE...COOLER AIR WILL BEGIN TO MAKE ITS WAY INTO OUR
NORTHERN ZONES TONIGHT. BY THURSDAY NIGHT AND EARLY
FRIDAY...NIGHTTIME LOWS MAY FALL INTO THE UPPER 30S INLAND IN OUR
NORTHERN COUNTIES WITH MID 40S TO MID 50S ELSEWHERE. 

.LONG TERM (FRIDAY NIGHT THROUGH TUESDAY)...BETTER MODEL AGREEMENT
AND CONSISTENCY IS BEGINNING TO DEVELOP FOR THE EXTENDED FORECAST
PERIOD. THE WEATHER PATTERN WILL FEATURE A COOL SURFACE HIGH
PRESSURE IN CONTROL AT THE START OF THE EXTENDED AND THIS WILL
KEEP THE WEATHER DRY AND COOLER THAN NORMAL WITH SEVERAL NIGHTS OF
LOWS IN THE UPPER 30S NORTH AND INTERIOR TO AROUND 50 IN THE
WARMER SPOTS. THE PATTERN WILL GRADUALLY BREAK OVER A SEVERAL DAY
PERIOD AS A STRONG TROUGH KICKS OUT OF THE PACIFIC NW AND TAKES A
SOUTHERN TRACK THROUGH THE LOWER MISSISSIPPI VALLEY. THE MAIN
DIFFERENCES REMAINING BETWEEN THE ECMWF AND GFS ON THIS SYSTEM
REVOLVE AROUND TIMING. WHILE THE GFS IS A BIT FASTER TO CLOSE THIS
SYSTEM OFF IN THE H5 FLOW THE ECMWF LEAVES IT SLIGHTLY MORE OPEN.
BOTH MODELS ESSENTIALLY THEN TURN IT SHARPLY NORTH THROUGH THE
OHIO VALLEY. THE RESULT ON OUR WEATHER HERE WILL BE FOR A WARMING
TREND AS THE WARM ADVECT ION AHEAD OF THE TROUGH ESTABLISHES A
RIDGE ACROSS THE GULF. TEMPERATURES ARE EXPECTED TO RETURN TO NEAR
OR ABOVE NORMAL BY THE START OF NEXT WEEK. PRECIP CHANCES WILL BE
NON EXISTENT FOR SEVERAL DAYS WITH THE HIGH PRESSURE AND DRY AIR
IN PLACE. BUT AS THE TROUGH APPROACHES IT SHOULD BRING A RETURN OF
MOISTURE AND THUS WILL KEEP THE CHANCE POPS FOR THE TAIL END OF
EXTENDED PERIOD.

&&

.AVIATION...DISCUSSION FOR 18Z TAFS. RAIN SHIELD IS SHOWING GOOD 
EROSION FROM THE WEST AT THIS POINT. SO WILL CARRY VCSH EVERYWHERE 
THIS AFTERNOON EXCEPT AT FMY AND RSW WHERE THERE WILL BE A FEW MORE 
HOURS OF STEADY RAIN. LIFR AND IFR CONDITIONS SHOULD IMPROVE TOWARDS 
00Z AS DRIER AIR ARRIVES WITH NORTHERLY WINDS AND MVFR CIGS ARE 
EXPECTED THEREAFTER.

&&

.MARINE...LIGHT TO MODERATE SHOWERS CAN BE EXPECTED THROUGH THIS
EVENING MAINLY FROM TAMPA BAY SOUTHWARD. A COLD FRONT WILL PUSH
THROUGH THE REGION TONIGHT WITH HIGH PRESSURE BUILDING IN BEHIND
THE FRONT. PRESSURE GRADIENT WILL TIGHTEN OVER THE COASTAL WATERS
THROUGH FRIDAY UNDER GENERALLY NORTHERLY TO NORTHWESTERLY FLOW.
WINDS WILL GRADUALLY INCREASE TO AROUND 20 KNOTS IN THE NEAR AND
OFF SHORE WATERS BY FRIDAY MORNING.

&&

.FIRE WEATHER...NO FIRE WEATHER CONCERNS UNTIL FRIDAY. BY
FRIDAY...A MUCH DRIER AIR MASS WILL SET UP OVER THE AREA WHICH WILL
DROP RH'S BELOW CRITICAL VALUES. CURRENTLY EXPECTING LESS THAN 3
HOURS OF DURATIONS BUT A WATCH OR WARNING MAY NOT BE OUT OF THE
QUESTION BY THURSDAY NIGHT OR FRIDAY MORNING.

&&

.PRELIMINARY POINT TEMPS/POPS...
TPA  60  72  48  65 /  50   5   5   5 
FMY  63  77  53  68 /  50  10   5   5 
GIF  56  73  48  66 /  50   5   5   5 
SRQ  62  73  49  66 /  50   5   5   5 
BKV  56  71  41  65 /  30   5   5   5 
SPG  61  71  53  65 /  50   5   5   5 

&&

.TBW WATCHES/WARNINGS/ADVISORIES...
FL...FLOOD WATCH UNTIL 11 PM EST THIS EVENING FOR CHARLOTTE-DE SOTO-
     HARDEE-HIGHLANDS-HILLSBOROUGH-LEE-MANATEE-PINELLAS-POLK-
     SARASOTA.

GULF WATERS...NONE.
&&

$$

SHORT TERM/MARINE/FIRE WEATHER...20/BARRON
LONG TERM/AVIATION...35/JOHNSON