FXUS62 KTBW 230712
AFDTBW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
212 AM EST WED DEC 23 2009
.SHORT TERM(TODAY-FRIDAY)...SLIGHT NARROW RIDGING ALOFT OVER THE
AREA TODAY AS CENTRAL U.S. LOW AMPLIFIES. SURFACE HIGH PRESSURE
DOWN THE EASTERN SEABOARD TO CONTINUE EASTERLY LOW LEVEL FLOW OVER
THE AREA INTO THE PLAINS STORM SYSTEM MODERATING TEMPERATURES TO
AROUND NORMAL AND INCREASING LOW LEVEL MOISTURE TODAY. TREND TO
CONTINUE TONIGHT WITH TEMPERATURES ABOVE NORMAL OVERNIGHT.
THE UPPER RIDGE MOVES INTO THE W ATLANTIC BY THURSDAY AS DEEP
UPPER LOW MOVES THROUGH THE CENTRAL U.S. PRODUCING MOIST SW FLOW
ALOFT. AT THE SURFACE WARM FRONT INTO MIDWEST STORM SYSTEM TO
DEVELOP AND MOVE OVER THE STATE AND INTO THE DEEP SOUTH WITH WARM
AND MOIST SE FLOW OVER THE AREA AS COLD FRONT REMAINS IN THE
CENTRAL GULF. SERIES OF VORTICITY MAXES BEGIN TO ROTATE OVERHEAD
DURING DIURNAL HEATING FOR A CHANCE OF AFTERNOON SHOWERS FOR MUCH
OF THE AREA WHILE DAYTIME TEMPERATURES WARM TO ABOUT 5 DEGREES
ABOVE NORMAL.
CHRISTMAS DAY...SHEARING AND WEAKENING UPPER SHORT WAVE AND VORTICITY
MAX TO PUSH COLD FRONT THROUGH THE E GULF EARLY FRIDAY MORNING
AND OVER THE FL PENINSULA DURING THE DAY WITH A CHANCE OF SHOWERS
AND SLIGHT CHANCE OF THUNDERSTORMS AHEAD AND ALONG THE FRONT. WARM
AND HUMID CONDITIONS AHEAD OF THE FRONT THEN COOLER AND DRIER HIGH
PRESSURE BEGINS TO BUILD INTO THE REGION LATE IN THE DAY OVER NORTHERN
AREAS.
.LONG TERM (FRIDAY NIGHT THROUGH TUESDAY)...U/L CUT-OFF LOW WILL
DRIFT OVER THE GREAT LAKES SATURDAY AND SUNDAY WITH SPLIT FLOW
PATTERN ACROSS THE U.S. SOUTHERN STREAM ZONAL FLOW FROM THE EASTERN
PACIFIC ACROSS THE GULF OF MEXICO AND FLORIDA WILL CREATE WEAK
OVERRUNNING ACROSS WEST CENTRAL AND SOUTHWEST FLORIDA THROUGH THE
WEEKEND WHICH WILL CREATE CONSIDERABLE CLOUDINESS. QUASI-STATIONARY
FRONTAL BOUNDARY ACROSS SOUTH FLORIDA WITH WEAK OVERRUNNING AND LIFT
PROVIDED BY AN U/L DISTURBANCE MAY GENERATE SOME LIGHT RAIN
SATURDAY...MAINLY ACROSS SOUTHWEST FLORIDA. SURFACE HIGH PRESSURE
WILL BUILD OVER THE AREA SATURDAY NIGHT AND SUNDAY WITH DRIER COOLER
AIR ADVECTING ACROSS THE REGION. GFS NOW KEEPING FRONTAL BOUNDARY
SOUTH OF THE FORECAST AREA THROUGH THE PERIOD WITH GENERALLY
NORTHERLY FLOW EACH DAY. AS THE U/L LOW OVER THE GREAT LAKES OPENS
UP MONDAY AND PUSHES OFF THE EAST COAST MONDAY NIGHT...ANOTHER COLD
FRONT WILL PUSH OVER WEST CENTRAL FLORIDA REINFORCING THE DRY COOL
AIR OVER THE AREA. TEMPERATURES WILL RUN BELOW CLIMATIC NORMALS
THROUGH THE PERIOD.
$$
AVIATION...VFR CONDITIONS EXPECTED TODAY AND TONIGHT. MOSTLY CLEAR
SKIES WILL GIVE WAY TO INCREASING HIGH LEVEL CLOUDINESS THIS
AFTERNOON PERSISTING OVERNIGHT.
&&
.MARINE...GRADIENT OVER THE E GULF TO TIGHTEN BETWEEN PLAINS STATES STORM
SYSTEM AND ATLANTIC SEABOARD HIGH PRESSURE TODAY AND TONIGHT WITH
INCREASING EASTERLY WINDS AND SEAS. SMALL CRAFT EXERCISE CAUTION
CONDITIONS ARE EXPECTED TO DEVELOP LATE TODAY THROUGH TONIGHT. WINDS AND
SEAS TO VEER SE-S AS COLD FRONT MOVES THROUGH THE CENTRAL GULF THURSDAY.
THE COLD FRONT TO SWEEP OVER THE E GULF FRIDAY WITH WINDS AND SEAS
SHIFTING NW BEHIND THE FRONT. HIGH PRESSURE TO BUILD INTO THE W GULF
REGION AND WEAKEN OVER THE WEEKEND WITH NW-N WINDS AND SEAS SLOWLY
SUBSIDING.
&&
.FIRE WEATHER...LOW LEVEL MOISTURE TO INCREASE NEXT FEW DAYS AHEAD
OF COLD FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 74 57 77 65 / 0 5 30 40
FMY 76 59 79 66 / 5 5 30 30
GIF 74 55 77 65 / 0 5 30 40
SRQ 75 57 79 65 / 0 5 30 40
BKV 74 50 76 63 / 0 5 30 50
SPG 72 60 76 66 / 0 5 30 40
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SHORT TERM/MARINE/FIRE WEATHER...25/DAVIS
LONG TERM/AVIATION...13/OGLESBY
