AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSONVILLE FL
715 AM EST SAT FEB 22 2003
UPDATED ZONES AND HWO TO INCLUDE NEW TORNADO WATCH # 18.
----------------------- PREVIOUS DISCUSSION ------------------------
CURRENTLY...UPPER TROF EXTENDS S ACROSS THE PLAINS INTO MEXICO. 2
DISTINCT LOBES OF ENERGY ROTATING THRU BASE OF TROF...ONE OVER
ARKLATEX REGION AND ONE OVER W OK. AT THE SFC...VERY DEEP LOW OVER W
MS (993 MB AT 06Z). WARM FRONT HAS LIFTED RAPIDLY N AWAY FROM OUR
CWA (COUNTY WARNING AREA) WITH IMPROVING VSBYS OVER FL AND LIKELY
IMPROVING OVER GA WITHIN THE NEXT FEW HRS. IN FACT...MOST LOW CLDS
HAVE BROKEN UP OVER FL...WITH JUST A MID DECK OF AC PRESENT (A SIGN
OF MID-LAYER INSTABILITY). MAIN SQUALL LINE EXTENDS FROM NW AL TO NR
KMOB AND SSW INTO THE GOMEX. SECONDARY LINE FROM NW AL TO S CENTRAL
AL. ANOTHER CLUSTER OF TSTMS BACK OVER ARKLATEX NR COLD AIR POOL
WITH UPPER LOW. AS A TESTAMENT TO HOW UNSTABLE THE AIRMASS OVER OUR
AREA HAS BECOME...ONE OR TWO SVR TSTMS OCCURRED LATE YESTERDAY
AFTN...AND STRONG TSTMS ARE ONGOING OVER THE GULF STREAM.
SEVERE WX...CONCERN CONTINUES FOR SVR WX OVER THE AREA TODAY. IF
ANYTHING...INGREDIENTS LOOKING EVEN MORE FAVORABLE THIS MORNING THAN
24 HRS AGO! MODELS STILL INDICATE 125 KT NEARLY S TO N UPPER JET
PLACING THE CWA IN THE RIGHT REAR QUAD TODAY. A 50 KT LOW-LEVEL JET
STILL PROGGED AS WELL. IN ADDITION...LINE SHOULD MOVE INTO HIGHLY
UNSTABLE AIRMASS. MESO-ETA FOUS GUIDANCE NOW SHOWS CAPES APPROACHING
1800 J/KG OVER N FL BY NOONTIME (AROUND THE TIME THE SQUALL LINE
SHOULD BE MOVING INTO THE AREA). BEST HELICITIES PRECEDE THE FLUX OF
INSTABILITY BY ABOUT 3 HRS...BUT STILL COMBINE TO GIVE ENERGY
HELICITY INDICES AROUND 2.0 OVER PORTIONS OF N FL. SCENARIO WILL
LIKELY BE ISOLATED SVR TSTMS (POSSIBLY TORNADIC) AHEAD OF SQUALL
LINE BY LATE THIS MORNING. THEN...STRAIGHT-LINE WINDS WITH SQUALL
LINE ITSELF MOVING THRU FROM EARLY TO MID-AFTN.
AM ALSO CONCERNED ABOUT LACK OF CLOUD SHIELD AHEAD OF THIS SYSTEM
WHICH WOULD TYPICALLY CUT DOWN ON OUR SFC HEATING IN THESE
SITUATIONS. WITH AMPLIFIED FLOW...CI ANVILS FROM CONVECTION TO THE W
ARE BEING ADVECTED NNW. THIS SHOULD KEEP MOST OF FL AND PARTS OF GA
PARTLY CLOUDY UNTIL LATE MORNING. WITH WARM AIR ADVECTION CONTINUING
IN EARNEST AND SUNSHINE...TEMPS WILL APPROACH 80 IN FL AND EXTREME
SE GA.
PUBLIC...WILL NOT CHANGE TOO MUCH IN CURRENT PACKAGE WITH WIDESPREAD
TSTMS MOVING ACROSS THE AREA. BUMPED UP HIGH TEMPS A COUPLE OF
DEGREES UNDER THE PARTLY CLOUDY ASSUMPTION MENTIONED ABOVE. WILL
RE-INTRODUCE MENTION OF NON-CONVECTIVE WIND GUSTS TO 40 MPH OVER FL
ZONES. BOSTON TECHNIQUE SHOWS POSSIBILITY OF 45 KT WINDS MIXING DOWN
(MINUS ENERGY LOST IN TRANSFER TO SFC). AGAIN...THIS IS DEPENDENT ON
SFC HEATING. HOWEVER...PRES FALLS WILL SUPPORT WINDY CONDITIONS
ANYWAY. WON'T ISSUE WIND ADVISORY ATTM...BUT WILL MENTION "CAUTION
ADVISED ON AREA WATERWAYS".
EXTENDED...LITTLE CHANGE TO CURRENT PACKAGE.
MARINE...SCA ALL AREAS WITH 25 KTS NEAR SHORE AND 30 KTS OFFSHORE.
COLD WATER TEMPS WILL CUT DOWN ON WINDS A BIT...BUT TSTMS WILL BRING
GUSTS TO THE SFC (WILL CONTINUE MENTION OF "WINDS AND SEAS HIGHER IN
TSTMS").
EAST CENTRAL FLORIDA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MELBOURNE FL
530 AM EST SAT FEB 22 2003
VERY STRONG TRANSPORT WINDS WILL PRODUCE DISPERSION VALUES ABOVE 80
ACROSS THE ENTIRE FORECAST AREA TODAY. AS A RESULT...A RED FLAG
WARNING WILL BE ISSUED. SEE FIRE WEATHER FORECAST FOR MORE DETAILS.
-------------------------------------------------------------------
...STRONG TO SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING...
RATHER TRANQUIL WX ACROSS EAST CENTRAL FLORIDA EARLY THIS MORNING
ALBEIT UNSEASONABLY MOIST W/ TDS NEAR 70. WEATHER WILL ABRUPTLY
DETERIORATE THIS AFTN AND EVE AS STAGE IS SET FOR STRONG SQUALL LINE
TO SWEEP ACROSS THE AREA.
SHRT WV OVER ERN TX WITH STRONG UPPER DIVERGENT PTRN AHEAD OF IT
IS RAPIDLY DEEPENING A LOW OVER THE LOWER MISS RIVER VLY. THIS
INITIAL SHRT WV WILL LIFT NE AS ADDITIONAL JET ENERGY ON BACKSIDE OF
TROF DROPS TO BASE OF TROF AND ADVANCES IT EWD. CONVECTION NOW
FIRING WELL S INTO THE GULF AND IS COINCIDIENT WITH TIGHT MID LEVEL
TEMP GRAD.
TODAY/TNT...RAPID SFC DEVELOPMENT WILL PRODUCE A STRONG LOW LVL WND
FIELD ALONG AND AHEAD OF SFC CD FNT. EXPECT SQUALL LINE NOW THRU THE
CENTRAL GULF TO TRACK EAST. THERE IS SOME POTENTIAL FOR THIS LINE TO
GET OUT AHEAD OF SUPPORT WITH A NEW LINE REFORMING BEHIND
IT...HOWEVER CURRENT SATELLITE TRNEDS INDICATE THAT CURRENT BNDRY
MAY PROVE TO BE THE MAIN SQUALL LINE. CONVECTION WILL BE SUPPORTED
BY DIFLUENT/DIVERGENT REGION OF UPPER JET TO THE N. IN FACT UPPER
WINDS CONTINUE TO INCREASE INTO SUNDAY WITH H25 WINDS ABV 100KTS. H8
WNDS BTWN 45 AND 50 KTS WILL PROVIDE STRONG SPEED SHEAR AS WELL.
INSTABILITY MAY STILL BE LACKING BUT LOOKS MORE FAVORABLE THAN
EARLIER GUIDANCE WITH BTWN 2 AND 3 DEGREES OF COOLING POTENTIAL AT
H5. REGARDLESS...STRONG WINDS ABV SFC WILL PROVIDE THREAT FOR
CONVECTIVE WIND GUSTS ABOVE 50 KTS AND WILL BE PRIMARY THREAT. STILL
SOME TORNADO THREAT FOR CONVECTION THAT DEVELOPS AHEAD OF MAIN
SQUALL LINE OVER NRN AREAS. SOME CONCERN FOR STRONG WIND GUSTS AWAY
FROM CONVECTION TODAY AS DIRURNAL MIXING RESUMES. WILL KEEP AVG
WINDS BLO ADV CRITERIA BUT INCLUDE MENTION OF HIGHER WIND GUSTS.
Heads UP sunshine state
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Heads UP sunshine state
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