Lake Wind Advisory 1, NWS Tampa Bay, FL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
236 AM EST THU JAN 12 2012

.SHORT TERM (TODAY-SATURDAY)...
THE SHORT TERM PERIOD WILL BEGIN TODAY WITH A SECONDARY COLD FRONT
PUSHING QUICKLY EAST ACROSS THE LOWER MISSISSIPPI VALLEY THIS
MORNING AND INTO THE FLORIDA PANHANDLE THIS EVENING. THIS WILL
HAVE SIGNIFICANTLY COLDER AIRMASS BEHIND IT...WITH AN ACCOMPANYING
MID LEVEL TROUGH. SOUTHWEST WINDS WILL INCREASE TODAY AHEAD OF THE
FRONT. BUFKIT INDICATING FAIR POTENTIAL FOR SUSTAINED WINDS OF 20
MPH ACROSS LEVY COUNTY WITH GUSTS TO 35 MPH...SO WILL GO WITH LAKE
WIND ADVISORY THERE. ELSEWHERE...BREEZY BUT NOT AS STRONG AS THE
BEST MIXING WILL HOLD OFF UNTIL LATE DAY WITH AN AREA OF HIGH
PRESSURE OVER THE SOUTHERN PENINSULA. FOR TODAY THE MET AND MAV
MOS NUMBERS SHOWED A FAIRLY HIGH DISCREPANCY. USED A BLEND BUT
FAVORED THE COOLER MET MOS. IT APPEARS THAT THE GFS DID NOT
INITIALIZE THE STRENGTH OF THE COLD POOL ACROSS NORTHERN ALABAMA
THIS EVENING...AND THUS IT HAS 850 MB TEMPS THAT APPEAR TO START
OUT TOO HIGH AND REMAIN HIGHER THAN THE NAM IN THE SHORT TERM. SO
WENT WITH THE BETTER INITIALIZED NAM SOLUTION. KEPT MENTION OF
SPRINKLES IN FOR TONIGHT WITH THE FRONT PASSING THROUGH THE NORTH
BY 06Z AND THROUGH THE ENTIRE AREA BY 12Z FRIDAY. HIGH PRESSURE
WILL RIDGE IN SHARPLY BEHIND THE FRONT. HOWEVER...NOTICING THAT
THE SOUTHWARD PUSH OF THE VERY COLD AIR AND STRONG COLD ADVECTION
HAS BEEN TEMPERED IN THE CURRENT MODEL RUNS. IT LOOKS LIKE THE 500
MB TROUGH IS LIFTING VERY QUICKLY TO THE NORTH AND SO THIS WILL
LIMIT THE STRONG ADVECTION OF DEEP COLD AIR. HOWEVER...MUCH
COOLER AIR IN THE LOW LEVELS SHOULD HAVE NO PROBLEM STREAMING
SOUTH OVERNIGHT. ADJUSTED TEMPS UP A BIT FOR LOWS...AS IT IS NOT A
GOOD RADIATIONAL COOLING NIGHT WITH FROPA AND CLOUDS. ON
FRIDAY...TEMPS WILL HOLD WELL BELOW NORMAL WITH ONLY UPPER 50S FOR
HIGHS NORTH. STRONG HIGH PRESSURE WILL CONTINUE TO RIDGE IN FROM
THE WEST AND SO FRIDAY NIGHT WILL BE A BETTER RADIATIONAL COOLING
NIGHT. ADJUSTED OVERNIGHT LOWS UPWARDS...OWING MAINLY TO THE FACT
THAT THE CURRENT MODEL SOLUTION NOT AS AGGRESSIVE WITH SOUTWHARD
MOVEMENT OF THE COLD AIR. STILL LOOKS LIKE A THREAT AT SUBFREEZING
TEMPS FOR THE NATURE COAST BUT WARMER ELSEWHERE. HIGH PRESSURE
BUILDS IN ON SATURDAY FOR A COOLER THAN NORMAL DAY WITH WARMING
ALOFT. TEMPERATURES WILL BE MAINLY IN THE 60S WITH FLOW TURNING
ONSHORE IN THE AFTERNOON TO KEEP THE COAST COOLER.

.LONG TERM (SATURDAY NIGHT - WEDNESDAY)...
COOL AND DRY AIRMASS WILL BE WELL ESTABLISHED BY SATURDAY NIGHT
WITH HIGH PRESSURE STRETCHING FROM THE NORTHERN GULF COAST
EASTWARD ACROSS NORTH FLORIDA. EXPECT WINDS TO BE LIGHT ENOUGH TO
ALLOW FOR GOOD RADIATIONAL COOLING...BUT MOISTURE CROSS SECTIONS
DO HINT AT SOME CIRRUS. WILL GENERALLY FOLLOW MAV GUIDANCE AND
SHOW BELOW FREEZING TEMPERATURES FOR THE COLDER AREAS OF THE
NATURE COAST WITH MID 30S ACROSS THE INTERIOR ELSEWHERE. ANOTHER
COLD SPOT WILL BE OUR INTERIOR SOUTHERN ZONES... ESPECIALLY FROM
HARDEE AND DESOTO COUNTIES EASTWARD INTO HIGHLANDS WHERE LOWS
COULD DROP BELOW FREEZING AS WELL.

THE RIDGE OF HIGH PRESSURE WILL MOVE NORTHEAST TO THE MID ATLANTIC
COAST BY MONDAY THEN OUT INTO THE ATLANTIC LATE MONDAY. THE NEXT
UPPER-LEVEL TROUGH WILL BE DIGGING TOWARD THE GULF COAST REGION
TUESDAY AND TUESDAY NIGHT SUPPORTING YET ANOTHER COLD FRONT FOR
FLORIDA. THE FRONT SHOULD BE LOCATED NORTHWEST OF OUR FORECAST AREA
TUESDAY NIGHT BUT SOME SHOWERS ARE POSSIBLE FROM THE TAMPA BAY AREA
NORTHWARD BEFORE DAYBREAK WEDNESDAY. THE GFS AND ECMWF ARE IN GOOD
AGREEMENT SHOWING THE FRONT CROSSING THE REGION ON WEDNESDAY WHICH
SHOULD BE PRECEDED BY A LINE OF SHOWERS AND PERHAPS EVEN A FEW
THUNDERSTORMS.

&&

.AVIATION...
MAINLY VFR AROUND TPA...PIE AND SRQ ALTHOUGH CAN NOT RULE OUT A
BRIEF MVFR VISIBILITY BEFORE SUNRISE. PGD...LAL...FMY AND RSW WILL
HAVE A GREATER CHANCE AT FOG THIS MORNING WHERE VISIBILITIES MAY
DROP TO A MILE OR LESS AT TIMES.

&&

.MARINE...
SOUTHWEST WINDS WILL INCREASE THIS AFTERNOON AND TONIGHT AHEAD OF
AN APPROACHING COLD FRONT. ADVISORY CRITERIA WINDS ARE EXPECTED
CENTRAL AND NORTHERN GULF WATERS BEGINNING THIS EVENING AND
LASTING THROUGH FRIDAY. SEAS WILL RESPOND AND BECOME ELEVATED AS
WELL. NORTHWEST WINDS BEHIND COLD FRONT TONIGHT. THEN HIGH
PRESSURE WILL BUILD IN FROM THE NORTHWEST TO BRING A CONTINUED
NORTHERLY FLOW. ELEVATED WINDS AND SEAS WILL CONTINUE THROUGH
SATURDAY BUT DIMINISH FROM ADVISORY LEVELS. FLOW TURNS EASTERLY BY
MONDAY BUT REMAINS MODERATELY STRONG WITH ELEVATED SEAS CONTINUING.

&&

.FIRE WEATHER...
NO CONCERNS TODAY WITH HIGH LOW LEVEL MOISTURE IN PLACE. COLD
FRONT PASSES TONIGHT AND WILL BRING BREEZY AND DRYING CONDITIONS.
WILL EXPECT SEVERAL HOURS OF CRITICALLY LOW RELATIVE HUMIDITIES ON
FRIDAY AND SATURDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
TPA  73  52  59  45 /   5  10   5   5
FMY  75  58  68  46 /   5  10   5   5
GIF  75  50  62  41 /   5  10   5   5
SRQ  71  55  61  45 /   5  10   5   5
BKV  74  44  59  34 /   5  10   5   5
SPG  70  55  60  50 /   5  10   5   5

&&

.TBW WATCHES/WARNINGS/ADVISORIES...
FL...LAKE WIND ADVISORY FROM NOON TODAY TO 7 PM EST THIS EVENING FOR
     LEVY.

GULF WATERS...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST FRIDAY
     FOR ENGLEWOOD TO TARPON SPRINGS OUT 20 NM-TARPON SPRINGS TO
     SUWANNEE RIVER OUT 20 NM.

     SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST FRIDAY
     FOR ENGLEWOOD TO TARPON SPRINGS OUT 20 TO 60 NM-TARPON
     SPRINGS TO SUWANNEE RIVER OUT 20 TO 60 NM.

&&

SHORT TERM/MARINE/FIRE WEATHER...35/JOHNSON
LONG TERM/AVIATION...63/JILLSON