Severe Thunderstorm Warning 26, NWS Tampa Bay, FL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
227 AM EDT WED MAY 4 2005

.SHORT TERM(TODAY - FRI)...CONSENSUS OF MODELS CONTINUE TO BE RATHER
SIMILAR THIS MORNING BUT EXACT DETAILS CONTINUE TO VARY FROM ONE RUN
TO THE NEXT. IN ANY EVENT IT STILL LOOKS LIKE A FEW MORE DAYS OF WET
WEATHER WITH ADDITIONAL STRONG STORMS ON TAP FOR THE FORECAST AREA
TODAY THROUGH THURSDAY.

PERSISTENT STALLED FRONTAL BOUNDARY ACROSS THE CENTRAL PENINSULA
ALONG WITH WEAK AREAS OF LOW PRESSURE MOVING ALONG THIS BOUNDARY
COMBINED WITH A HIGHLY DIVERGENT FLOW ALOFT...AND SERIES OF SHORT
WAVES MOVING THROUGH THE 50H FLOW WILL ALL CONTRIBUTE TO GOOD LARGE
SCALE LIFT ACROSS THE AREA TODAY THROUGH THURSDAY...WHICH WILL RESULT
IN NUMEROUS SHOWERS AND STORMS. WITH MODEL SOUNDING DATA INDICATING
STEEP MID LEVEL LAPSE RATES AND RATHER COOL MID LEVEL TEMPS (-10 TO
-11C) THERE WILL BE THE POSSIBILITY OF MORE STRONG TO SEVERE STORMS
ACROSS THE FA DURING THIS AFTERNOON...WITH THE PRIMARY HAZARDS BEING
LARGE HAIL AND STRONG GUSTY WINDS...AND WILL HIT ON ALL OF THIS IN
THE HWO LATER THIS MORNING. MODEL GUIDANCE SHOWS POPS IN THE 60-70%
RANGE AND THIS LOOKS QUITE REASONABLE GIVEN THE EXPECTED LARGE SCALE
LIFT FROM FEATURES MENTIONED ABOVE...SO WILL DEPICT IN THE GRIDS AND
ZONES.

SIMILAR TO YESTERDAY MORNING THE GFS APPEARS TO BE OVERDOING QPF
AMOUNTS (CONVECTIVE FEEDBACK PROBLEMS) SO WILL AGAIN UNDERCUT BUT
STILL EXPECTING ON AVERAGE ONE QUARTER TO ONE HALF INCH RAIN AMOUNTS
TODAY AND AGAIN ON THURSDAY...WITH SOME LOCALIZED AMOUNTS UP TO 2 TO
3 INCHES POSSIBLE WITH THE STRONGER STORMS. EXTENSIVE CANOPY OF
CLOUDS AND EXPECTED PRECIP WILL KEEP MAX TEMPS BELOW SEASONAL NORMS
TODAY AND THURSDAY WITH HIGHS IN THE UPPER 70S FAR NORTH TO 80 TO
LOWER 80S CENTRAL AND SOUTH.

BY FRIDAY MODELS SHOW DEEPEST MOISTURE AXIS SHIFTING EASTWARD IN
TANDEM WITH UPPER TROUGH AND DEEPENING SFC LOW MOVING UP ALONG THE
MID ATLANTIC WITH SKIES BECOMING PARTLY CLOUDY. THE NAM IS STILL A
BIT FASTER THAN THE GFS IN MOVING THE UPPER TROUGH/DEEPER MOISTURE
AXIS OUT OF THE FA...AND GIVEN THE DIFFERENCES IN MODEL SOLUTIONS
OVER THE LAST SEVERAL DAYS...I PREFER TO HANG ON TO A LOW POP MENTION
(20%) ON FRIDAY AS THE TROUGH MOVES THROUGH. TEMPS ON FRIDAY WILL
CONTINUE A FEW DEGREES BELOW SEASONAL NORMS.

&&

.LONG TERM (FRI NGT - TUE)...AFTER AN ACTIVE PERIOD OF WEATHER ALL
WEEK A RETURN TO DRIER CONDITIONS IS ON THE WAY. THE MODELS ARE
SLOWLY STARTING TO SHOW SOME AGREEMENT WITH THURSDAY AND FRIDAY
MORNING AS THE MOST LIKELY DAYS FOR SIGNIFICANT RAIN AND
THUNDERSTORM ACTIVITY AS A MID LEVEL TROUGH AND ASSOCIATED FRONTAL
BOUNDARY SWEEPS THROUGH THE AREA...THEN MOVING AWAY INTO THE
NORTHEAST ATLANTIC BY SATURDAY MORNING. GLOBAL PATTERN CHARTS SHOW A
PSEUDO OMEGA CONFIGURATION WITH A STRENGTHENING HIGH PRESSURE CENTER
OVER THE CENTRAL AND SOUTHEAST STATES FLANKED BY THE LOW PRESSURE
CENTERS...THE ONE MOVING OVER THE NORTH EAST ATLANTIC COAST AND
ANOTHER OVER THE NORTHWEST US MAINLAND. THE RIDGE MIGRATES SOUTHWARD
AND FLATTENS NE OF FLORIDA BRINGING A GENERALLY EAST TO NORTHEAST
WIND REGIME THROUGH TUESDAY WITH MOSTLY LIGHT WINDS OVER LAND AND
DRY CONDITIONS.

FOR NEXT WEEK..UNDER THE EXPECTED STABLE CONDITIONS IT IS LIKELY WE
WILL HAVE AFTERNOON SEA BREEZES DURING THE FORECAST PERIOD AS THE
GRADIENT FLOW WILL LIKELY REMAIN VERY WEAK AND VARIABLE ALONG WITH
WARM TEMPERATURES AND MOSTLY SUNNY SKIES.

&&

.MARINE...WINDS AND SEAS SHOULD REMAIN BELOW 15 KNOTS AND 5 FEET
TODAY THROUGH THE END OF THE WORK WEEK AND INTO THE UPCOMING
WEEKEND...BUT COULD SEE SOME LOCALLY HIGHER WIND/SEAS IN THE
VICINITY OF TSTMS TODAY AND THURSDAY...OTHERWISE NO HIGHLIGHTS ARE
ANTICIPATED.

&&

.FIRE WEATHER...NO FIRE WEATHER CONCERNS EXPECTED THROUGH THE END OF
THE WORK WEEK AS LOW LEVEL MOISTURE AND RAIN CHANCES REMAIN HIGH
ACROSS THE FORECAST AREA.

&&

.PRELIMINARY POINT TEMPS/POPS...
TPA  81 68 82 66/ 70 60 50 30
FMY  84 68 84 67/ 70 60 50 30
GIF  83 66 83 64/ 70 60 50 30
SRQ  80 67 81 68/ 70 60 50 30
BKV  81 64 81 60/ 60 50 50 30

.TBW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

SHORT TERM...MCMICHAEL
LONG TERM....REYNES

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
447 AM EDT WED MAY 4 2005

FLZ039-042-043-048>052-055>057-060>062-065-041500-
CHARLOTTE-CITRUS-DE SOTO-HARDEE-HERNANDO-HIGHLANDS-HILLSBOROUGH-LEE-
LEVY-MANATEE-PASCO-PINELLAS-POLK-SARASOTA-SUMTER-
447 AM EDT WED MAY 4 2005

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WEST CENTRAL AND SOUTHWEST
FLORIDA.

.DAY ONE...TODAY:

UPPER LEVEL DISTURBANCES AND A NORTHWARD MOVING FRONTAL BOUNDARY
ACROSS THE SOUTH CENTRAL PENINSULA WILL COMBINE WITH A MOIST AND
UNSTABLE AIR MASS AND RESULT IN NUMEROUS SHOWERS AND THUNDERSTORMS
ACROSS ALL OF WEST CENTRAL AND SOUTHWEST FLORIDA TODAY. A FEW SHOWERS
OR STORMS CAN BE EXPECTED AT JUST ABOUT ANYTIME DURING THIS
MORNING...BUT THE GREATEST COVERAGE AND INTENSITY OF SHOWERS AND
STORMS IS EXPECTED TO BE OCCUR DURING THE AFTERNOON AND EVENING
HOURS.

WITH RATHER COLD TEMPERATURES IN THE MID LEVELS OF THE ATMOSPHERE
SOME STORMS COULD BECOME STRONG TO SEVERE WITH DAMAGING WINDS AND
LARGE HAIL. IN ADDITION FREQUENT CLOUD TO GROUND LIGHTNING AND VERY
HEAVY RAINS WILL ACCOMPANY THE STORMS. THE HEAVY RAINFALL MAY RESULT
IN MINOR FLOODING OF LOW LYING AND POOR DRAINAGE AREAS...AS WELL AS
THE PONDING OF WATER ON ROADWAYS.

RESIDENTS AND VISITORS OF WEST CENTRAL AND SOUTHWEST FLORIDA SHOULD
BE ALERT TO RAPIDLY CHANGING WEATHER CONDITIONS TODAY. IF LIGHTNING
IS OBSERVED OR THUNDER IS HEARD MOVE INDOORS IMMEDIATELY. STAY TUNED
TO NOAA WEATHER RADIO OR YOUR LOCAL MEDIA OUTLET FOR POSSIBLE WATCHES
AND OR WARNINGS LATER TODAY.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY:
ANOTHER ROUND OF SHOWERS AND STORMS...SOME AGAIN POSSIBLY STRONG WILL
OCCUR ON THURSDAY AS ADDITIONAL UPPER LEVEL DISTURBANCES AND WEAK
WAVES OF LOW PRESSURE MOVE ACROSS THE REGION. THE PRIMARY HAZARDS
FROM THE STORMS WILL AGAIN BE FREQUENT LIGHTNING...VERY HEAVY
RAINS....STRONG GUSTY WINDS...AND HAIL. DURING FRIDAY THROUGH TUESDAY
HIGH PRESSURE WILL BUILD IN OVER THE REGION WITH NO ADDITIONAL
HAZARDOUS WEATHER EXPECTED AT THIS TIME.

.SPOTTER CALL TO ACTION STATEMENT...

SPOTTER ACTIVATION MAY BE NECESSARY LATER TODAY AND TONIGHT.

&&

FOR ADDITIONAL WEATHER INFORMATION...CHECK OUR WEB SITE AT
HTTP://WWW.SRH.NOAA.GOV/TBW (LOWER CASE)

MCMICHAEL

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
841 AM EDT WED MAY 4 2005

FLZ049-041330-
PASCO-
841 AM EDT WED MAY 4 2005

...STRONG THUNDERSTORMS WILL AFFECT WESTERN PASCO COUNTY...

A STRONG THUNDERSTORM IS LOCATED OVER SOUTHWEST PASCO COUNTY. THIS
STORM IS MOVING EAST AT 20 MPH...AND WILL AFFECT NEW PORT
RICHEY...JASMINE ESTATES AND MOON LAKE ESTATES...UNTIL 930 AM EDT.
EXCESSIVE CLOUD TO GROUND LIGHTNING IS EXPECTED IF OUTSIDE...CROUCH
DOWN IN A LOW SPOT...AWAY FROM TALL OBJECTS. IF INDOORS...REFRAIN
FROM USING ELECTRICAL APPLIANCES. HAIL UP TO ONE HALF INCH IN
DIAMETER IS EXPECTED. PEA SIZE HAIL HAS BEEN REPORTED WITH THIS
STORM. RAINFALL RATES OF 1 TO 2 INCHES PER HOUR WILL OCCUR.
MOTORISTS CAN EXPECT PONDING OF WATER ON ROADS...AND MINOR FLOODING
OF POOR DRAINAGE AREAS.

RJS