000
FXUS62 KTBW 051821
AFDTBW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
121 PM EST MON JAN 5 2009

.SHORT TERM TONIGHT - WEDNESDAY...HIGH PRESSURE IN THE MID/UPPER LEVELS
AND AN ATTENDANT SURFACE RIDGE AXIS ACROSS THE CENTRAL PENINSULA WILL
MAINTAIN DRY CONDITIONS OVER THE FORECAST AREA TONIGHT. INCREASING LOW
LEVEL MOISTURE COMBINED WITH LIGHT WINDS SHOULD AGAIN ALLOW FOR AREAS
OF LOW CLOUDS AND FOG ALONG WITH SOME SEA FOG DEVELOPMENT OVER THE COASTAL
WATERS OVERNIGHT AND WILL INCLUDE A MENTION OF IN THE GRIDS/ZONES. AFTER
SOME LOW CLOUDS AND FOG EARLY TUESDAY MORNING A WARM AN INCREASINGLY HUMID
DAY IS EXPECTED UNDER PARTLY CLOUDY SKIES AS A DEEPENING SOUTHERLY WIND
FLOW DEVELOPS ACROSS THE FORECAST AREA AHEAD OF A MID/UPPER LEVEL TROUGH
OVER THE SOUTHERN PLAINS. TEMPERATURES ON TUESDAY WILL RUN SOME 8-10 DEGREES
ABOVE NORMAL WITH READINGS CLIMBING TO 80 ALONG THE COAST AND THE LOWER
80S INLAND.

DURING TUESDAY NIGHT CLOUDS WILL BE ON THE INCREASE ACROSS THE FORECAST
AREA AS THE AFOREMENTIONED MID/UPPER TROUGH AND ATTENDANT COLD FRONT MOVES
INTO THE LOWER MS VALLEY WITH A PRE-FRONTAL LINE OF SHOWERS/STORMS MOVING
INTO THE FL PANHANDLE. CURRENT MODELS SUGGEST A 20 POP MENTION FOR SHOWERS
AFTER MIDNIGHT ACROSS LEVY COUNTY AND THE NORTHERN COASTAL WATERS WITH
10 ACROSS THE REMAINDER OF THE REGION. IT WILL A MILD NIGHT WITH TEMPS
IN THE LOWER/MID 60S WITH SOUTH WINDS 10 MPH.

ON WEDNESDAY THE AFOREMENTIONED COLD FRONT IS FORECAST TO MOVE THROUGH
WEST CENTRAL AND SOUTHWEST FLORIDA AS A STRONG MID/UPPER LEVEL TROUGH
ADVANCES EASTWARD WITH THE TROUGH BECOMING NEGATIVELY TILTED AS IT MOVES
OFF THE U.S. EAST COAST EARLY ON THURSDAY. ONGOING PRE-FRONTAL CONVECTIVE
LINE OF SHOWERS/STORMS ALONG AND AHEAD OF THE COLD FRONT OVER THE NATURE
COAST IN THE MORNING WILL SWEEP SOUTHEAST THROUGH THE REMAINDER OF THE
FORECAST AREA DURING THE AFTERNOON. STRONG FRONTAL FORCING COMBINED WITH
DEEP LAYERED SHEAR...AND A LOW LEVEL JET IN THE 45-50 KNOT RANGE MOVING
ACROSS THE REGION MAY BE SUPPORTIVE OF A FEW STRONG STORMS WITH DAMAGING
WINDS...BUT LIMITED INSTABILITY VIA MODEL SOUNDING DATA SHOULD KEEP THE
OVERALL SEVERE THREAT TO A MINIMUM AT THIS TIME. MODEL POPS HAVE INCREASED
SLIGHTLY FROM PREVIOUS RUNS...SO WILL NUDGE UP POPS INTO THE 50-60 RANGE
WITH THE FRONTAL PASSAGE. CLOUD COVER AND RAIN CHANCES WILL RESULT IN
COOLER TEMPERATURES ON WEDNESDAY WITH HIGHS IN THE LOWER TO MID 70S NORTH
INTO CENTRAL ZONES AND UPPER 70S FAR SOUTH.

.LONG TERM WEDNESDAY NIGHT - MONDAY...MODELS IN GOOD AGREEMENT ON
A DEEP EASTERN U.S. TROUGH AXIS OVER THE DEEP SOUTH WEDNESDAY NIGHT...WITH
A COLD FRONT PASSING THE CWA EITHER WEDNESDAY OR WEDNESDAY EVENING.
HIGH PRESSURE WILL BUILD IN FROM THE GULF BEHIND THIS FRONT AND THEN
GET REINFORCED THURSDAY NIGHT BY ANOTHER HIGH BUILDING DOWN FROM CANADA.
THIS HIGH EVENTUALLY WILL MOVE INTO THE ATLANTIC AND RIDGE BACK ACROSS
THE STATE THROUGH SATURDAY AS FLOW ALOFT CHANGES FROM TROUGHINESS TO
FLAT.

PROGRESSIVE PATTERN ALOFT WILL CONTINUE FOR THE EARLY PART OF NEXT
WEEK THOUGH...AS ANOTHER TROUGH MOVES ACROSS THE GREAT LAKES AND
INITIATES ANOTHER FRONT ACROSS THE DEEP SOUTH SUNDAY. LATEST GFS AND
DGEX BOTH HAVE THIS FRONT MOVING ACROSS THE CWA FASTER THAN THE
ECMWF. GIVEN THE EXPECTED FAST MOVING FLOW ALOFT...WOULD NOT BE
SURPRISED TO SEE THE GFS SOLUTION COME TO FRUITION. PREVIOUS FORECASTS
HAVE LEANED MORE TOWARD THE ECMWF...AND WILL BLEND THE TWO IN THIS
PACKAGE AS DO NOT WANT TO FLIP FLOP ENTIRELY.

.AVIATION...HAVE FEW TO SCATTERED CLOUDS THIS AFTERNOON WITH BASES
HOVERING AROUND THE MVFR TO VFR RANGE. MAY HAVE SOME PERIODS WITH
BROKEN DECKS...ESPECIALLY SOUTH OF TAMPA BAY...AND HAVE TEMPO GROUPS
FOR THESE DECKS THIS AFTERNOON. OVERNIGHT...EXPECT ANOTHER ROUND OF
FOG/LOW STRATUS WITH MVFR TO IFR VISIBILITIES/CEILINGS. THESE SHOULD
CLEAR BY MID MORNING AS WINDS PICK UP FROM THE SOUTH.

.MARINE...NEAR SHORE SEA BREEZE COMPONENT WILL COLLAPSE AFTER SUNSET
TONIGHT WITH A LIGHT SOUTHEAST WIND IN THE 5-10 KNOT RANGE EXPECTED
OVERNIGHT. INCREASINGLY MOIST AIR OVERRUNNING THE COOLER GULF WATERS
MAY SUPPORT SOME DENSE SEA FOG OVERNIGHT AND WILL INCLUDE PATCHY WORDING
FOR NOW IN THE GRIDS AND AFTERNOON COASTAL PACKAGE. SOUTHERLY WIND FLOW
WILL BEGIN TO INCREASE OVER THE WATERS TUESDAY AND TUESDAY NIGHT WITH
A PERIOD OF EXERCISE CAUTION OR LOW END SMALL CRAFT ADVISORY CONDITIONS
A POSSIBILITY BY WEDNESDAY AS A COLD FRONT APPROACHES AND MOVES THROUGH
THE WATERS...WITH SOUTHWEST WINDS SHIFTING INTO THE NORTHWEST DURING
WEDNESDAY AFTERNOON AND EVENING. LIGHTER WINDS AND LOWER SEAS ARE EXPECTED
ON THURSDAY AS SURFACE HIGH PRESSURE BUILDS IN OVER THE WESTERN GULF.
ANOTHER WEAKER FRONT WILL PASS THROUGH THE WATERS THURSDAY NIGHT WITH
LITTLE FANFARE...FOLLOWED BY HIGH PRESSURE BUILDING IN OVER THE SOUTHEASTERN
STATES EARLY ON FRIDAY THEN SHIFTING EAST INTO THE ATLANTIC FRIDAY NIGHT
INTO SATURDAY WITH OVERALL FLOW BECOMING NORTHEAST TO EAST.

.FIRE WEATHER...INCREASING LOW LEVEL MOISTURE WILL KEEP HUMIDITY VALUES
ABOVE CRITICAL LEVEL THROUGH MID WEEK WITH NO FIRE WEATHER CONCERNS OR
HEADLINES ANTICIPATED AT THIS TIME. DRIER AIR IN THE WAKE OF THE COLD
FRONT WILL LOWER HUMIDITIES TO NEAR CRITICAL LEVELS ON THURSDAY.

.PRELIMINARY POINT TEMPS/POPS...
TPA  61  80  64  73 /   5   5  10  50
FMY  61  80  65  77 /   5   5  10  40
GIF  60  83  64  73 /   5   5  10  50
SRQ  59  79  65  72 /   5   5  10  50
BKV  55  82  61  72 /   5   5  10  50
SPG  62  77  64  72 /   5   5  10  50

.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.

SHORT TERM/MARINE/FIRE WEATHER...57/MCMICHAEL
LONG TERM/AVIATION...55/SHARP