[MCD] SWOMCD

Wed Apr 26 16:05:49 UTC 2006

ACUS11 KWNS 261602
SWOMCD
SPC MCD 261602 
GAZ000-FLZ000-261730-

MESOSCALE DISCUSSION 0669
NWS STORM PREDICTION CENTER NORMAN OK
1102 AM CDT WED APR 26 2006

AREAS AFFECTED...NRN FL

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 261602Z - 261730Z

TRENDS ARE BEING MONITORED FOR INCREASING SEVERE THREAT AND
POSSIBILITY OF A WW.

COLD POOL ASSOCIATED WITH MESOSCALE CONVECTIVE SYSTEM HAS OVERSPREAD
MUCH OF SOUTHEAST LOUISIANA AND SOUTHERN MISSISSIPPI INTO THE
WESTERN FLORIDA PANHANDLE...WITH STRONGEST PORTION SURGING SOUTHEAST
OF THE LOUISIANA COAST.  HOWEVER...MORE VIGOROUS CLUSTER OF STORMS
...NOW DEVELOPING EAST OF MOBILE...REMAINS IN CLOSE PROXIMITY TO
COASTAL AREAS...AND APPEARS SUPPORTED BY FORCING ASSOCIATED WITH
IMPULSE EMBEDDED WITHIN STRONGER MID/UPPER STREAM OF FLOW ALONG GULF
COASTAL AREAS. MODELS SUGGEST THIS FORCING WILL GRADUALLY SHIFT
EAST THROUGH THE FLORIDA BIG BEND REGION BY THE 20-21Z TIME FRAME.

SURFACE DEW POINTS ACROSS THE FLORIDA BIG BEND/EASTERN PANHANDLE...
INCLUDING THE TALLAHASSEE AREA...TO THE SOUTH OF AN OLD CONVECTIVE
BOUNDARY WHICH EXTENDS THROUGH THE VALDOSTA/SAVANNAH GEORGIA AREAS
...ARE AROUND 70F.  THIS IS CONTRIBUTING TO  MIXED LAYER CAPE OF
1000 TO 2000 WITH INSOLATION...WHICH SEEMS LIKELY TO MAINTAIN
VIGOROUS CONVECTIVE DEVELOPMENT INTO AND THROUGH THE AFTERNOON
HOURS.

HIGH PRECIPITABLE WATER CONTENT AIR /AROUND 2 INCHES/ FEEDING INTO
CONVECTION WILL SUPPORT VERY HEAVY RAINFALL...BUT LOW HUMIDITIES AT
MID LEVELS WILL ENHANCE EVAPORATIVE COOLING IN DOWNDRAFTS...AND
ADDITIONAL SIGNIFICANT COLD POOLS APPEAR POSSIBLE.  MODELS SUGGEST
THAT A WESTERLY LOW-LEVEL JET WILL STRENGTHEN ACROSS NORTHERN
FLORIDA WITH APPROACH OF UPPER IMPULSE.  AS THIS OCCURS...FORWARD
PROPAGATION OF ANY COLD POOLS WILL BE ENHANCED...ALONG WITH RISK OF
DAMAGING WINDS.  THIS SEEMS POSSIBLE NEAR/EAST OF TALLAHASSEE
THROUGH THE JACKSONVILLE AREAS DURING THE 18-21Z TIME FRAME.

..KERR.. 04/26/2006

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...CHS...TBW...JAX...TAE...

31708067 30498072 30038121 29678215 29088320 28798544
29968549 30878492 31298410 31258269 31638168 31838116 

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