FXUS62 KTBW 250656
AFDTBW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
157 AM EST FRI DEC 25 2009
.SHORT TERM (TODAY-SUNDAY)...STRONG U/L CUTOFF LOW WILL LIFT THROUGH
THE MID MISSISSIPPI VALLEY TODAY WITH A COLD FRONT PUSHING ACROSS
THE EASTERN GULF OF MEXICO AND FLORIDA. BAND OF SHOWERS AND
THUNDERSTORMS OVER THE EASTERN GULF OF MEXICO WILL PUSH ACROSS WEST
CENTRAL AND SOUTHWEST FLORIDA TODAY...WITH THE BEST CHANCE OF RAIN
BEFORE NOON. LOW LEVEL AND U/L DYNAMICS WILL BE WEAKENING AS MAIN
SUPPORT LIFTS NORTH OF THE AREA...AND EXPECT BAND OF SHOWERS AND
THUNDERSTORMS TO WEAKEN AS IT MOVES ONSHORE THIS MORNING. A FEW
STRONGER SHOWERS OR THUNDERSTORMS MAY PRODUCE BRIEF HEAVY RAIN AND
WIND GUSTS TO 40 MPH. THE COLD FRONT WILL PUSH EAST OF THE AREA
THIS AFTERNOON WITH SURFACE HIGH PRESSURE BUILDING OVER THE
SOUTHEAST U.S. TONIGHT AND SATURDAY WITH CLEARING SKIES AND MUCH
DRIER COOLER AIR ADVECTING ACROSS THE FORECAST AREA. HIGH
TEMPERATURES SATURDAY WILL STRUGGLE TO REACH THE LOW 60S OVER THE
NATURE COAST...MID 60S OVER WEST CENTRAL FLORIDA...AND LOWER 70S
OVER SOUTHWEST FLORIDA. COOL AIR WILL HOLD OVER THE NATURE COAST
SATURDAY NIGHT AND SUNDAY...BUT THE FRONTAL BOUNDARY TO THE SOUTH
WILL BEGIN LIFT NORTH AS A WARM FRONT ON SUNDAY REACHING THE CENTRAL
FLORIDA PENINSULA. A WEAK U/L DISTURBANCE WILL RIDE OVER THE
BOUNDARY SUNDAY WITH A SLIGHT CHANCE OF LIGHT RAIN AS WEAK
OVERRUNNING OCCURS ALONG AND NORTH OF THE FRONTAL BOUNDARY.
.LONG TERM (SUNDAY NIGHT THROUGH THURSDAY)...A LARGE AREA OF HIGH
PRESSURE WILL BUILD INTO THE REGION FROM THE NORTHWEST MONDAY NIGHT
WITH THE MAIN CENTER PASSING WELL TO OUR NORTH TUESDAY AND
WEDNESDAY. THIS WILL RESULT IN GRADUAL CLEARING SUNDAY NIGHT...THEN
LOTS OF SUNSHINE FOR MONDAY AND TUESDAY. THE HIGH WILL MOVE TO THE
MID-ATLANTIC COAST WEDNESDAY NIGHT AS AN UPPER-LEVEL TROUGH BEGINS
TO DIG TOWARD THE GULF COAST REGION. THIS WILL ENERGIZE OUR NEXT
WEATHER MAKER...WHICH MODELS BRING IN HERE SOMETIME THURSDAY OR
FRIDAY. THE GFS DEVELOPS A LOW IN THE WESTERN GULF WEDNESDAY NIGHT
AND MOVES IT TO CENTRAL FLORIDA BY LATE THURSDAY. THE 12Z ECMWF RUN
DOES NOT DEVELOP A GULF LOW...BUT DOES DRAG A COLD FRONT INTO THE
REGION ON THURSDAY. EITHER WAY...IT LOOKS LIKE CLOUDS WILL INCREASE
ON WEDNESDAY NIGHT WITH THE BEST RAIN CHANCES ARRIVING DURING THE
DAY ON THURSDAY. SINCE THIS IS A DAY 7 FORECAST...WILL JUST KEEP
CHANCE POPS AT THIS TIME. IT IS QUITE LIKELY THAT THE DETAILS AND
TIMING WILL CHANGE AS WE GET CLOSER TO THE EVENT.
TEMPERATURES WILL SPEND MUCH OF THE PERIOD BELOW NORMAL BUT NO
FREEZES ARE EXPECTED AT THIS TIME. TEMPERATURES COME BACK TO NEAR
NORMAL BY THURSDAY AS THE NEXT SYSTEM APPROACHES.
$$
AVIATION...CLOUDS WILL GRADUALLY THICKEN THIS MORNING WITH SHOWERS
AND MVFR CEILINGS AND VISIBILITIES ARRIVING AROUND DAYBREAK.
CONDITIONS IMPROVE SLOWLY BEHIND THE COLD FRONT DURING THE AFTERNOON
AND EVENING HOURS.
&&
.MARINE...THE COLD FRONT PUSHING ACROSS THE EASTERN GULF OF MEXICO
WILL CONTINUE TO PRODUCE HAZARDOUS SEAS AND WINDS AROUND 20 KNOTS
THROUGH LATE AFTERNOON. WINDS AND SEAS WILL GRADUALLY SUBSIDE
TONIGHT AND SUNDAY AS HIGH PRESSURE BUILDS OVER THE WATERS WITH A
WEAKENING GRADIENT.
&&
.FIRE WEATHER...RELATIVE HUMIDITY WILL REMAIN WELL ABOVE CRITICAL
LEVELS TODAY. BUT WITH THE DRIER AIR ADVECTING OVER THE AREA ON
SATURDAY...RELATIVE HUMIDITY VALUES MAY DROP BELOW CRITICAL LEVELS
WITH THE MAIN THREAT NORTH OF TAMPA. MOISTURE WILL BEGIN TO RECOVER
ON SUNDAY WITH MINIMUM RELATIVE HUMIDITY VALUES REMAINING ABOVE
CRITICAL LEVELS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 73 52 65 51 / 60 10 10 20
FMY 78 57 70 53 / 60 10 10 20
GIF 76 50 66 47 / 60 10 10 20
SRQ 73 51 66 51 / 60 10 10 20
BKV 72 42 63 38 / 60 10 10 20
SPG 73 55 65 53 / 60 10 10 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...SMALL CRAFT ADVISORY UNTIL 4 PM EST FRIDAY FOR BONITA
BEACH TO ENGLEWOOD OUT 20 TO 60 NM-ENGLEWOOD TO TARPON
SPRINGS OUT 20 TO 60 NM-TARPON SPRINGS TO SUWANNEE
RIVER OUT 20 TO 60 NM.
&&
$$
SHORT TERM/MARINE/FIRE WEATHER...13/OGLESBY
LONG TERM/AVIATION...63/JILLSON
