Severe Thunderstorm Warning 112, NWS Tampa Bay, FL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
130 PM EDT SUN JUL 22 2007

.SHORT TERM (TONIGHT - TUESDAY)...GUIDANCE IN GOOD AGREEMENT
REGARDING A LOW PRESSURE SYSTEM OVER THE EASTERN U.S. WHICH DEEPENS
INTO THE NORTHEAST GULF AND NORTHERN FLORIDA TONIGHT AND ON MONDAY.
GFS IS NOW SHOWING A MID LEVEL BROAD CLOSED LOW OVER THE ATLANTIC
COAST STATES WHICH REMAINS NEARLY STATIONARY THROUGH TUESDAY. AT THE
SURFACE A WEAK FRONTAL BOUNDARY REACHES AND LINGERS AROUND THE
NORTHERN HALF OF THE STATE TONIGHT WHILE HIGH PRESSURE DEVELOPS
SOUTH OF FLORIDA FROM THE ATLANTIC. THIS RIDGE THEN SLOWLY MIGRATES
NORTHWARD AND REACHING CENTRAL FLORIDA BY MONDAY AFTERNOON...PUSHING
THE FRONTAL BOUNDARY NORTH OF FLORIDA INTO THE WESTERN ATLANTIC AND
AWAY FROM THE AREA. THE FRONT...HOWEVER...SEEMS TO MOVE BACK INTO
THE SOUTHEASTERN STATES AND LINGERS OVER FLORIDA AND THE NORTHERN
GULF ON TUESDAY AFTERNOON. ALSO...SMALL IMPULSES OF ENERGY SEEM TO
ROTATE AROUND THE MAIN TROUGH AND PASS OVER THE NORTHERN HALF OF THE
CWA.

AS THE RIDGE STRENGTHENS AND MOVES NORTHWARD EXPECT WINDS GENERALLY
FROM THE EAST SOUTHEAST TO PREVAIL THROUGH TUESDAY MORNING...THEN
SWITCHING TO THE SOUTHWEST IN THE AFTERNOON AS THE RIDGE SAGS BACK
INTO SOUTHERN FLORIDA. THE PRESENCE OF THE REMNANTS OF THE BOUNDARY
NORTH OF THE CWA WILL KEEP ENOUGH LOW LEVEL MOISTURE IN
PLACE...WHICH COMBINED WITH WHATEVER ADDITIONAL SUPPORT THE PASSING
SMALL VORTEXES COULD CONTRIBUTE ALOFT WILL HELP IN GENERATING
SCATTERED THUNDERSTORMS EACH DAY...MAINLY IN THE AFTERNOON AND EARLY
EVENING HOURS.

WITH STILL PLENTY OF CLOUD COVER AND SHOWER ACTIVITY EXPECTED
THROUGH TUESDAY...TEMPS SHOULD REMAIN BASICALLY AT CLIMO WITH SOME
LOCATIONS OVER INTERIOR AREAS SLIGHTLY WARMER THAN NORMAL ESPECIALLY
IN THE AFTERNOON.

&&

.LONG TERM (TUESDAY NIGHT - SUNDAY)...THE CUT-OFF LOW NEAR THE GREAT
LAKES REMAINS IN THAT GENERAL VICINITY THROUGH THE PERIOD. CLOSER TO
HOME THE MID LEVEL RIDGE SUPPRESSED SOUTH OF FL PUTS A MOIST SW FLOW
OVER THE PENINSULA INTO THURSDAY. ON THE SURFACE... THE RIDGE OVER
SOUTH FLORIDA MIGRATES OVER CENTRAL FL BY THE END OF THE WEEK. THIS
SHIFTS THE PREDOMINANT WEST FLOW TO EAST FLOW SOUTH AND WEST FLOW
NORTH AND WHAT WOULD BE A MORE TYPICAL SUMMER PATTERN. BUT TOWARD
THE END OF THE WEEK THE GFS ELONGATES THE MID LEVEL TROUGH OVER THE
AREA AND ROTATES EAST OF FL PUTTING THE AREA IN A NORTHWEST FLOW.
THAT PATTERN WOULD LEAD TO LESS THUNDERSTORM COVERAGE AND
TEMPERATURES A DEGREE OR TWO ABOVE CLIMO.

&&

.AVIATION...PERIODS OF MVFR/IFR THROUGH THE REST OF THE  AFTERNOON
AND EARLY EVENING HOURS AS CONVECTION DEVELOPS NEAR THE COASTLINE.
VFR CONDITIONS SHOULD RETURN TONIGHT AT ALL TAF SITES.

&&

.MARINE...WEAK PRESSURE GRADIENT ACROSS THE COASTAL WATERS WILL
CONTINUE TONIGHT WITH HIGH PRESSURE SLOWLY MOVING INTO THE SOUTHERN
MARINE ZONES ON MONDAY. WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW
HIGHLIGHT CRITERIA THROUGH THE FORECAST PERIOD EXCEPT IN THE
VICINITY OF THUNDERSTORMS WHICH WILL BRING PERIODS OF ROUGH
SEAS...DEADLY CLOUD TO WATER LIGHTNING AND GUSTY WINDS.

&&

.FIRE WEATHER...NO FIRE WEATHER CONCERNS AT THIS TIME.

&&

.PRELIMINARY POINT TEMPS/POPS...
TPA  73  89  74  89  /  30  50  30  50
FMY  73  89  73  90  /  30  50  30  50
GIF  73  89  72  90  /  30  50  30  50
SRQ  74  88  73  89  /  30  50  30  50
BKV  68  89  70  89  /  30  50  30  50
SPG  77  88  77  88  /  30  50  30  50

&&

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

SHORT TERM/MARINE...AR
LONG TERM/AVIATION...CP

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
531 AM EDT SUN JUL 22 2007

FLZ039-042-043-048>052-055>057-060>062-065-221500-
LEVY-CITRUS-SUMTER-HERNANDO-PASCO-PINELLAS-HILLSBOROUGH-POLK-
MANATEE-HARDEE-HIGHLANDS-SARASOTA-DE SOTO-CHARLOTTE-LEE-
531 AM EDT SUN JUL 22 2007

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

.DAY ONE...TODAY AND TONIGHT.

...THUNDERSTORM IMPACT...

UPPER LEVEL DISTURBANCES MOVING ACROSS THE AREA ALONG WITH A MOIST
UNSTABLE AIRMASS WILL PRODUCE ISOLATED TO NUMEROUS THUNDERSTORMS
TODAY. ISOLATED THUNDERSTORMS ARE OCCURRING ON THE COASTAL WATERS
AND ARE EXPECTED TO INCREASE TO SCATTERED AND SPREAD INLAND DURING
THE MORNING AND BECOME NUMEROUS DURING THE AFTERNOON AS THE SEA BREEZE
FORMS AND MOVES INLAND.

THE COASTAL WATERS CAN EXPECT THUNDERSTORMS TO BE SCATTERED FROM LATE
MORNING THROUGH EARLY AFTERNOON.

THESE THUNDERSTORMS WILL CONTAIN FREQUENT DEADLY CLOUD TO GROUND
LIGHTNING...GUSTY WINDS...AND HEAVY DOWNPOURS PRODUCING MINOR STREET
FLOODING.

A FEW OF THESE STORMS MAY BECOME STRONG WITH HAIL AND WINDS THAT
APPROACH SEVERE LEVELS.

IF A THUNDERSTORM APPROACHES YOUR LOCATION...MOVE INDOORS IMMEDIATELY.
REMEMBER... IF YOU CAN HEAR THE THUNDER THEN YOU ARE CLOSE ENOUGH
TO THE STORM TO BE STRUCK BY LIGHTNING.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

...THUNDERSTORM IMPACT...

THUNDERSTORMS ARE EXPECTED EACH DAY...MAINLY IN THE AFTERNOON
AND EARLY EVENING HOURS.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS SHOULD MONITOR THE WEATHER AND SELF ACTIVATE IF NEEDED.

09/RKR