FXUS62 KTBW 270701
AFDTBW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
159 AM EST FRI NOV 27 2009
.SHORT TERM (TODAY - SUNDAY)...SPLIT-FLOW PATTERN PREVAILS ACROSS
THE U.S. WITH AN ACTIVE SOUTHERN STREAM EMANATING FROM AN OPEN WAVE
OVER NORTHWEST MEXICO ADVECTING ABUNDANT MOISTURE OVER TEXAS AND THE
WESTERN GULF OF MEXICO. MEANWHILE...A PROGRESSIVE NORTHERN STREAM
REMAINS IN PLACE WITH A POTENT STORM SYSTEM APPROACHING THE CA/OR/WA
COASTLINE AND A LONGWAVE TROF CARVED OUT FROM CANADAS HUDSON BAY
SOUTHWARD ACROSS THE U.S. EAST COAST. BELOW NORMAL TEMPERATURES
ANTICIPATED TODAY ACROSS THE FORECAST AREA WITH COLD ADVECTION
PREVAILING WITHIN A NORTHERLY FLOW OVER WEST CENTRAL AND SOUTHWEST
FLORIDA. FREEZING TEMPERATURES OBSERVED EARLY THIS MORNING OVER
PORTIONS OF MS WITH DEW POINTS IN THE LOWER 30S OVER THE FLORIDA
PANHANDLE...ADVECTING SOUTHWARD TOWARD THE FORECAST AREA. MIN TEMPS
TONIGHT AND SATURDAY MORNING WILL BE THE COLDEST FOR THIS PARTICULAR
WEATHER EVENT...A SOLID FIVE DEGREES COLDER THAN WHAT WILL BE
OBSERVED EARLY THIS FRIDAY MORNING. EXPECT MIN TEMPS TO WARM BY
ABOUT FIVE DEGREES BY EARLY SUNDAY MORNING AS AIRMASS
MODIFIES...COLD ADVECTION DIMINISHES...AND BOUNDARY LAYER FLOW VEERS
TOWARD THE EAST TAPPING SLIGHTLY HIGHER DEW POINTS. LITTLE CHANGE
MADE TO THE ONGOING FORECAST.
.LONG TERM (SUNDAY NIGHT-WEDNESDAY)...SUNDAY NIGHT EXPECTED TO BE
LAST OF COOL NIGHTS AS CLEAR SKIES AND LIGHT WINDS PRODUCE GOOD
RADIATIONAL COOLING WITH SURFACE HIGH PRESSURE OVER THE REGION
SLOWLY DRIFTING INTO THE W ATLANTIC. FAIRLY FLAT FAST UPPER FLOW TO
PUSH SURFACE HIGH PRESSURE FURTHER INTO THE ATLANTIC AS WEAK FRONTAL
BOUNDARY MOVES INTO THE REGION. BOUNDARY TO STALL ACROSS N FL
EXTENDING INTO THE W GULF PARALLEL TO THE UPPER FLOW TUESDAY. MODELS
BRING SHORTWAVE FROM S TX THROUGH THE DEEP SOUTH AND DEVELOP LOW
PRESSURE AREA ON THE FRONT IN NW GULF AND MOVE IT INTO THE N CENTRAL
GULF REGION WEDNESDAY MORNING THEN THROUGH THE DEEP SOUTH INTO
THURSDAY. SOME MODELS VARY ON THE EXACT TIMING AND PLACEMENT OF
FEATURES BUT ALL HAVE SOME SYSTEM AFFECTING THE AREA MID WEEK. WILL
KEEP CHANCE POPS MOST AREAS AT THIS TIME FOR LATE
TUESDAY...WEDNESDAY INTO THURSDAY. WILL CONTINUE TO MONITOR SYSTEM
AND ADJUST TIMING AND PLACEMENT OF PRECIPITATION AS THE EVENTS
DEVELOP. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL THROUGH
MID WEEK.
&&
.AVIATION...MOSTLY CLEAR SKIES AND VFR CONDITIONS.
&&
.MARINE...COLD ADVECTION CONTINUES ACROSS THE COASTAL AND OFFSHORE
WATERS THIS MORNING...GRADUALLY DIMINISHING THIS AFTERNOON AND
TONIGHT. PRESSURE GRADIENT RESPONDS ACCORDINGLY AND WILL MAINTAIN
THE MARGINAL SMALL CRAFT ADVISORY THROUGH 15Z FOR THE COASTAL AND
OFFSHORE WATERS. WIND AND SEA CONDITIONS WILL CONTINUE TO IMPROVE
OVERNIGHT INTO SATURDAY AS A HIGH PRESSURE SYSTEM PROPAGATES
EASTWARD ACROSS THE NORTHERN GULF. WINDS WILL VEER THROUGH THE
PERIOD BECOMING NORTHEAST AND EAST THROUGH SATURDAY AND GENERALLY
LIGHT EAST ON SUNDAY.
&&
.FIRE WEATHER...DRY AND COOLER AIRMASS ADVECTING OVER THE PENINSULA
THROUGH TODAY AND INTO THE WEEKEND WILL SET THE STAGE FOR CRITICAL
FIRE WEATHER CONDITIONS TODAY AND SATURDAY. BELOW CRITICAL RELATIVE
HUMIDITY VALUES ARE EXPECTED TODAY ACROSS INLAND COUNTIES AND A RED
FLAG WARNING WILL REMAIN IN EFFECT. GIVEN LOWER DEW POINTS
CURRENTLY OBSERVED UPSTREAM WILL EXPAND THE FIRE WEATHER WATCH TO
INCLUDE THE NORTHERN SECTIONS FOR SATURDAY. VEERING BOUNDARY LAYER
FLOW SUNDAY INTO EARLY NEXT WEEK WILL INCREASE RH VALUES AND LESSEN
THE POTENTIAL FOR FIRE WEATHER CONCERNS AHEAD OF THE NEXT WEATHER
SYSTEM APPROACHING EARLY-MID WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 65 44 68 50 / 0 0 0 0
FMY 68 45 71 51 / 0 0 0 0
GIF 65 42 68 48 / 0 0 0 0
SRQ 66 45 69 49 / 0 0 0 0
BKV 63 34 67 39 / 0 0 0 0
SPG 64 51 68 54 / 0 0 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...RED FLAG WARNING FROM 11 AM THIS MORNING TO 6 PM EST THIS
EVENING FOR CHARLOTTE-CITRUS-DE SOTO-HARDEE-HERNANDO-
HIGHLANDS-HILLSBOROUGH-LEE-LEVY-MANATEE-PASCO-POLK-SARASOTA-
SUMTER.
FIRE WEATHER WATCH FROM SATURDAY MORNING THROUGH SATURDAY
AFTERNOON FOR CHARLOTTE-CITRUS-DE SOTO-HARDEE-HERNANDO-
HIGHLANDS-HILLSBOROUGH-LEE-LEVY-MANATEE-PASCO-POLK-SARASOTA-
SUMTER.
GULF WATERS...SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR BONITA
BEACH TO ENGLEWOOD OUT 20 NM-BONITA BEACH TO ENGLEWOOD OUT
20 TO 60 NM-ENGLEWOOD TO TARPON SPRINGS OUT 20 NM-ENGLEWOOD
TO TARPON SPRINGS OUT 20 TO 60 NM-TARPON SPRINGS TO
SUWANNEE RIVER OUT 20 NM-TARPON SPRINGS TO SUWANNEE RIVER
OUT 20 TO 60 NM.
&&
$$
SHORT TERM/MARINE/FIRE WEATHER...10/LAMARRE
LONG TERM/AVIATION...25/DAVIS
