Severe Thunderstorm Warning 175, NWS Tampa Bay, FL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY-RUSKIN, FL
251 AM EST SAT DEC 27 1997

WARM FRONT NOW EXTENDING FROM JUST N OF DAB WEST TO CRYSTAL RIVER AT
07Z BASED ON DEW POINT ANALYSIS. WRMFNT WILL CONTINUE TO LIFT N TODAY
AS SFC LOW CONTINUES TO DEVELOP OVER THE GLFMX AND TRACKS NORTHEAST
ALONG THE FRONT MOVING ACROSS THE NORTHERN PENINSULA LATER THIS
MORNING...AND THEN CONTINUING UP ALONG THE ERN SEABOARD THROUGH
TONIGHT. MODELS ARE ALL FAIRLY SIMILAR WITH MOVING VERY IMPRESSIVE
MID-UPPER LVL DYNAMICS...LOW LVL 50-60 KNOT JET ACROSS THE CENTRAL
AND NORTHERN PENINSULA THROUGH THIS AFTERNOON. THESE FEATURES
COMBINED WITH ENHANCED MOISTURE CONVERGENCE FROM DVLPG SURFACE LOW
AND INCREASING UPPER LVL DIVERGENCE BEING ENHANCED BY STRONG 140+
KNOT JET ALOFT WILL RESULT IN LOCALLY HEAVY RAINS TODAY ALONG WITH
THE THREAT OF SEVERE T-STORMS.

AT THE MOMENT FIRST BATCH OF HEAVY RAIN AND ISOLATED T-STOMRS MOVING
THROUGH MANATEE...HILLSBOROUGH AND POLK COUNTIES. AS THIS BAND CONTS
MOVG RAPIDLY NEWD...MAY SEE A BRIEF BREAK IN THE PRECIP TOWARD
SUNRISE...BEFORE A SECOND ROUND OF SHOWERS AND T-STORMS DEVELOP AND
MOVE ACROSS THE REGION LATER THIS MORNING INTO THIS AFTERNOON ALONG
AND AHEAD OF TRAILING COLD FRONT. THIS COLD FRONT WILL MOVE THROUGH
THE NORTHERN FORECAST AREA LATER THIS MORNING..THEN THROUGH THE
CENTRAL AND SOUTHERN FORECAST AREAS THIS AFTERNOON AND TONIGHT.
AS MENTIONED ABOVE SEVERE THUNDERSTORMS WILL BE POSSIBLE ALONG AND
AHEAD OF THIS COLD FRONT AS MID-UPPER DYNAMICS APPROACH AND WIND
FIELDS INCREASE. ATTM WOULD SUGGEST CATEGORICAL POPS FOR ALL ZONES
TODAY WITH THE MENTION OF HEAVY RAINS...POSSIBLE FLOODING AND WORDING
FOR SEVERE T-STORMS. BY LATER TONIGHT THE COLD FRONT WILL BE MOVING
OFF THE SE FLORIDA COAST WITH A MUCH DRIER AIRMASS MOVING INTO THE
REGION ON A BRISK NORTHWESTERLY WIND FLOW. MUCH COOLER TEMPERATURES
ARE EXPECTED IN THE WAKE OF THIS FRONT AS GOOD COLD AIR ADVECTION
TAKES PLACE. AT THE MOMENT FAN NUMBERS MAY BE A BIT WITH MINS TEMPS
WHICH TENDS TO BE A BIAS OF THIS MODEL...AND WITH FAIRLY BREEZY
CONDITIONS EXPECTED OVERNIGHT...PERFER THE SLIGHTLY WARMER LOOKING
FWC NUMBERS. ON SUNDAY HIGH PRESSURE WILL BUILD IN OVER THEj NRN
PENINSULA WITH M. SUNNY SKIES AND COOL TEMPS EXPECTED.

MCMICHAEL

FLZ039-042-043-048>052-055>057-060>062-065-GMZ830-850-853-271600-

WEST CENTRAL AND SOUTHWEST FLORIDA HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
422 AM EST SAT DEC 27 1997

...FLOOD WATCH IN EFFECT THROUGH TONIGHT FOR LEVY...CITRUS...SUMTER...
HERNANDO...PASCO...PINELLAS...HILLSBOROUGH...MANATEE...SARASOTA...POLK...
HARDEE...DE SOTO...AND HIGHLANDS  COUNTIES...

...TORNADO WATCH IN EFFECT UNTIL 10 AM EST FOR LEVY...CITRUS...HERNANDO...
SUMTER...PASCO...PINELLAS...HILLSBOROUGH...MANATEE...POLK...HARDEE...
DESOTO...HIGHLANDS...AND SARASOTA COUNTIES...

A WARM FRONT STRETCHES ACROSS THE NORTH-CENTRAL FLORIDA PENINSULA
TO A DEVELOPING SURFACE LOW OVER THE NORTHEAST GULF OF MEXICO JUST
WEST OF CEDAR KEY EARLY THIS MORNING.   THE LOW WILL DEEPEN AND MOVE
EAST NORTHEAST ACROSS NORTH FLORIDA BY SUNRISE WITH A COLD FRONT
TRAILING OVER THE EASTERN GULF OF MEXICO.  RAIN WITH EMBEDDED
THUNDERSTORMS ARE NOW MOVING ACROSS THE REGION BETWEEN SARASOTA
AND LAKELAND EARLY THIS MORNING.  A SQUALL LINE WILL LIKELY DEVELOP
AHEAD OF THE COLD FRONT OVER THE EASTERN GULF OF MEXICO LATER THIS
MORNING.  THIS  LINE  OF THUNDERSTORMS WILL THEN MOVE TOWARD THE
CEDAR KEY AND CRYSTAL RIVER AREAS BY LATE THIS MORNING...THEN BEGIN TO
AFFECT THE REMAINDER OF THE WEST CENTRAL AND SOUTHWEST FLORIDA AREAS
DURING THE AFTERNOON AND EARLY EVENING HOURS.

THE MAIN THREAT FROM THE THUNDERSTORMS TODAY WILL BE DAMAGING
WINDS IN EXCESS OF 50 MPH...VERY HEAVY RAINS WHICH MAY CAUSE
FLOODING...FREQUENT DEADLY LIGHTNING...SMALL HAIL...AND POSSIBLY SHORT
LIVED TORNADOES AND MARINE WATERSPOUTS. ALL RESIDENTS AND MARINERS
SHOULD STAY ALERT TO ANY RAPIDLY CHANGING WEATHER CONDITIONS TODAY
AND MOVE INDOORS OR SEEK A SAFE HARBOR IMMEDIATELY IF THREATENING
WEATHER APPROACHES YOUR LOCATION. ALL EMERGENCY MANAGEMENT
OFFICIALS AND SKYWARN STORM SPOTTERS ARE ASKED TO RELAY ANY REPORTS
OF ADVERSE WEATHER TO THE NATIONAL WEATHER SERVICE OFFICE HERE IN
RUSKIN.

THE GROUND REMAINS QUITE SATURATED WITH MANY RIVERS ALREADY ABOVE
FLOOD STAGE.  RAINFALL TOTALS OF 3 TO 5 INCHES WILL BE POOSIBLE WITHIN THE
FLOOD WATCH AREA THROUGH TODAY.  THIS COULD CAUSE SERIOUS FLOODING IN
MANY LOCATIONS WITH  RIVERS LIKELY RISING FURTHER.  ALL PERSONS LIVING IN
FLOOD PRONE AREAS MUST BE PREPARED TO MOVE TO HIGHER GROUND IF
NECESSARY.  THIS IS A POTENTIALLY DANGEROUS SITUATION...SO STAY TUNED TO
NOAA  WEATHER RADIO OR YOUR LOCAL RADIO/TV OR CABLE TV STATIONS FOR
UPDATES AND POSSIBLE WARNINGS DURING THIS DEVELOPING WEATHER
SITUATION. ANOTHER HAZARDOUS WEATHER OUTLOOK WILL BE ISSUED BY THIS
OFFICE LATER THIS MORNING.

MCMICHAEL