Severe Thunderstorm Warning 53, NWS Jacksonville, FL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
220 PM EDT THU JUN 13 2002

CURRENTLY...CONVERGENT OH-SHORE FLOW OVER NE FL HAS ENHANCED
CONVECTION...MOSTLY HEAVY PRECIP SHOWERS...ALONG THE COAST FROM
NASSAU TO NORTHERN CLAY COUNTY. CONVECTION IS VERTICALLY ORIENTED
WITH SLIGHT PROPAGATION S AND W IN LOW LVL FLOW. UPR LVL TROUGH HAS
MOVED WEST OF THE STATE WITH INVERTED SFC TROUGH STILL RESIDING NEAR
SOUTHERN ST. JOHNS COUNTY SW TO WESTERN MARION. TEMPS IN THE UPPER
80S AND NEAR 90 ACROSS S FL...AND MID 90S REPORTED ACROSS INTERIOR
GA ZONES WHERE DRIER AIR RESIDES. TODAYS STRONGER CONVECTION WILL
FOCUS OVER FL ZONES NEAR THE TROUGH.

TONIGHT...AM TRENDING TOWARD THE ETA FAMILY FOR GUIDANCE FOR THIS
PACKAGE. THINK AVN IS OVERDONE WRT ITS SFC LOW GENERATION OFF-SHORE
OF CENTRAL FL BY 00Z AND DID POORLY WITH THE 12Z VORT LOCATION OVER
NE FL. THE ETA FAMILY HOWEVER DID THE BEST WITH THE VORT LOCATION
AND FOCUSES TODAY ON MESO-LOW FORMATION ACROSS THE INTERIOR AND SEA
BREEZE CONVERGENCE. PWS JUST BELOW TWO INCHES TODAY SO EXPECT HEAVY
PRECIP CELLS AND SLOW MOVEMENT OF STORMS WITH STEERING TO THE EAST
AND LIGHT. THE ETA SOLUTIONS INDICATE THE APPROACH OF A PRE-FRONTAL
TROUGH/VORT MAX OVER SOUTHERN GA TONIGHT. WILL ACCOUNT FOR 20-30%
PRECIP ALL ZONES AND WORD FOR EVENING CONVECTION TONIGHT FOR FL.

FRI AND FRI NIGHT...WITH SW FLOW AND TEMPS REACHING THE LOWER 90S
EXPECT A MORE EAST COAST SEA BREEZE COLLISION AHEAD OF THE FRONT FRI
AFTERNOON/EVE. SEA BREEZE MAY BE KEPT CONFINED TO COASTAL COUNTIES
TOMORROW...PERHAPS EVEN OFF-SHORE...DUE TO STRONGER SW SFC FLOW OF
10-15 KTS AND STEERING FLOW SW-W 20-25 KTS. WILL KEEP POPS FOR
INLAND AREAS SLIGHTLY BELOW COASTAL ZONES FOR INLAND DEVELOPMENT AS
ATMOS DESTABILIZES WITH HEATING AND FRONT APPROACHING. FROPA HOLDING
OFF UNTIL SAT MORN FOR GA...AND SAT FOR FL.

SAT AND SAT NIGHT...FRONT PRESSES S ACROSS THE PENINSULA SAT AND
WILL CONTINUE WITH CHC POPS ALL ZONES. WILL TREND TOWARD 60% FOR
SOUTHERN FL ZONES WHERE INSTABILITY WILL LINGER IN PROXIMITY OF THE
FRONT AND DECREASE NORTHWARD INTO INTERIOR GA ZONES TO 30%. SAT
NIGHT 20-30% FOR FL EVENING CONVECTION...WITH EXPECTED CLEARING
OVERNIGHT. NIL POPS AND MOSTLY CLEAR SKIES FOR GA SAT NIGHT.
SLIGHTLY COOLER TEMPS SUN MORN IN MID TO UPPER 60S.

SUN...WEAK IMPULSES TRAIL SFC FROPA IN BASE OF UPR TROUGH ALTHOUGH
MEAN LAYER MOISTURE IS CONCENTRATED SOUTH OF THE PENINSULA. PRECIP
WATERS DECREASE TO LESS THAN AN INCH. WILL GO PARTLY CLOUDY ALL
ZONES.

EXTENDED...SFC BERMUDA HIGH AXIS BUILDS NORTHWARD MON OVER SOUTH FL.
LOW LVL SW FLOW RISING TEMPS INTO THE LOWER 90S AND ENHANCING EAST
COAST SEA BREEZE COLLISION. WILL GO SLIGHT CHC FOR FL ZONES MON. SFC
LOW APPROACHES THE REGION FROM THE SW WHILE UPR LVL TROUGH DIGS FROM
GREAT LAKES TUE. SFC SYSTEM MOVES NE THROUGH WED WITH HIGH PRESS
BUILDING BEHIND OVER THE UPR MISSISSIPPI VALLEY AND WESTWARD FROM
THE ATLANTIC. WILL GO CHC POPS ALL ZONES TUE THROUGH THU. TEMPS NEAR
NORMAL IN THE EXTENDED WITH HIGHS NEAR 90 AND LOWS NEAR 70.

MARINE...NO HEADLINES. CURRENT WINDS LIGHT AND VARIABLE WITH
ON-SHORE CONVERGENT FLOW OVER NE FL. WINDS INCREASING AHEAD OF FRONT
FRI FROM THE SW 15 TO 20 KTS...BECOMING NORTHWEST LATE SAT FOLLOWING
THE FRONTAL PASSAGE.

PRELIM...
AMG BB 071/092 071/088 065 24255
SSI BB 073/090 074/087 072 24235
JAX BB 072/092 073/088 066 24345
SGJ BB 074/091 074/088 072 24344
GNV BB 072/094 072/089 067 24333
OCF BB 072/094 073/090 068 24333

.JAX...
.GA...NONE.
.FL...NONE.

BROYLES/CARROLL