Severe Thunderstorm Warning 95, NWS Tallahassee, FL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
242 PM EDT FRI JUN 14 2002

MODEL DISCUSSION: MODELS INDICATE THAT THE LONG WAVE TROUGH WILL
CONTINUE TO AMPLIFY W/ A LOBE OF VORTICITY SWINGING ACROSS AL AND GA
TONIGHT. THE FRONT WOULD GET ABOUT HALF WAY ACROSS THE CWFA BY
AROUND 06Z. IT IS NOW EXPECTED TO CLEAR ALL BUT OUR SE BIG BEND
ZONES BY 12Z SAT. IT THEN WEAKENS AS IT MOVES INTO THE NRN
PENINSULA. THE MAIN IMPACT ON THE CWFA FROM THIS SYSTEM WILL LIKELY
BE THIS AFTERNOON AND THIS EVENING. LOCAL RADARS INDICATING THAT
ISOLATED THUNDERSTORMS HAVE DEVELOPED AHEAD OF THE FRONT ACROSS SRN
AL AND THE FL PANHANDLE IN AN AREA OF LOW LEVEL CONVERGENCE WHICH IS
BEING ENHANCED BY AN OUTFLOW BOUNDARY. LAPS ANALYSES INDICATE THAT
ATMOSPHERE IS DESTABILIZING RAPIDLY IN SE AL. UPPER LEVEL DIFFLUENCE
OVER THE AREA WILL ENHANCE UPDRAFTS. UNIDIRECTIONAL SHEAR PROFILES
AND GRADUALLY INCREASING MID LEVEL FLOW MAY RESULT IN A FEW OF THE
CELLS EVOLVING INTO SHORT BOWING LINES WHICH WOULD PRODUCE A
DAMAGING WIND THREAT. WILL MENTION STRONG GUSTY WINDS IN TSTMS FOR
THIS EVENING.

THE FRONT WILL NOT CLEAR OUR SE ZONES UNTIL EARLY SAT. ON SUN, A
SECOND FRONT APPROACHES FROM THE N. HOWEVER, IT SHOULD BE MOISTURE
STARVED. PW WILL BE BELOW AN INCH AND PLENTY OF MID LEVEL DRY AIR
AND SUBSIDENCE MOVES IN OVER THE AREA. THEREFORE SEA BREEZES SHOULD
BE SUPPRESSED. BY MON, THE FRONTAL BOUNDARY WILL BE STATIONARY
ACROSS THE CWFA AND PW WILL RECOVER TO ABOUT 1.4, ENOUGH FOR SEA
BREEZE POPS.

PUBLIC FORECAST: FIRST PERIOD POPS WILL BE BASED ON RADAR TRENDS,
BUT WILL LIKELY USE LIKELY POPS NW AND 20 OVER SE BIG BEND W/ SCT
POPS IN BETWEEN. FOR TONIGHT...THE ATMOSPHERE MAY BE STABILIZED BY
RAIN COOLED OUTFLOW. HOWEVER, BELIEVE MAV POPS ARE TOO LOW. WILL
BLEND CURRENT FORECAST W/ ETA/NGM MOS. FOR SAT, WILL ONLY MAINTAIN
POP OVER SE BIG BEND, AND PERHAPS FRANKLIN CO. THEN NO POPS FOR SAT
NIGHT INTO SUN. FOR MON, WILL ADVERTISE SCT POPS DUE SEA BREEZE.

MARINE: WINDS ARE NOT INCREASING AS RAPIDLY AS MODELS WERE
INDICATING, SO PLAN TO KEEP FORECAST BELOW SCEC RANGE FOR THIS
EVENING. BEYOND THAT, WILL STEP BACK FROM A POST FRONTAL WIND SHIFT
TO NW AS THE FRONT IS EXPECTED TO STALL OVER OR JUST S OF THE WATERS.

FIRE WX: DROPPED WATCH FOR HIGH DISPERSION. EXPECTING SURFACE AND
TRANSPORT WINDS TO BE PRETTY CLOSE TODAY AND THAT DROPPED OUR
DISPERSION INDICES DOWN INTO THE 60S. RED FLAG CONDITIONS NOT
ANTICIPATED ON SAT EITHER.

EXTENDED: MRF AND ECMWF BOTH SHOW THE LONG WAVE TROUGH PERSISTING IN
THE ERN U.S INTO TUE, BUT THEN PULLING OUT RAPIDLY TO THE NE BY WED.
IN THE WAKE OF THE RETREATING WESTERLIES, WE ARE LEFT WITH A BROAD
UPPER LEVEL RIDGE ACROSS THE SRN U.S. FOR THE END OF NEXT WEEK. AT
THE SURFACE, A LARGE RIDGE WILL EXTEND FROM THE N ATLANTIC E INTO
THE ERN U.S. W/ IT/S AXIS N OF US. THE OLD FRONTAL BOUNDARY WILL
STILL BE STALLED ACROSS OUR CWFA TUE AND WED AND THEN BEGIN LOSING
IT/S IDENTITY ON THU. WILL MAINTAIN DIURNAL CONVECTION IN FORECAST
EACH DAY. BY FRI, THE BOUNDARY SHOULD BE GONE, BUT LOW LEVEL SE FLOW
AROUND THE RIDGE TO THE N WILL WARRANT POPS DUE TO THE SEA BREEZE.

PRELIM NUMBERS...

TLH  69 92 63 92  420-
PFN  73 88 70 87  420-
DHN  66 90 63 90  6-0-
ABY  67 90 63 90  6-00
VLD  70 92 61 92  4100
CTY  72 90 65 90  240-

.TLH...
.AL...NONE.
.GA...NONE.
.FL...NONE.

WOOL