[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 251852
SWOMCD
SPC MCD 251851 
FLZ000-252045-

MESOSCALE DISCUSSION 2577
NWS STORM PREDICTION CENTER NORMAN OK
1251 PM CST SAT DEC 25 2004

AREAS AFFECTED...PARTS OF SRN FL

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 251851Z - 252045Z

SEVERE TSTM PROBABILITIES WILL BE INCREASING RAPIDLY LATE THIS
AFTERNOON AND EVENING. TSTMS EXPECTED TO DEVELOP/MOVE INTO PARTS OF
SRN FL WILL HAVE THE POTENTIAL FOR DAMAGING WINDS/TORNADOES.  A WW
WILL LIKELY BE NEEDED BY LATE AFTERNOON.

PRESSURE FALLS HAVE BEEN INCREASING ACROSS SRN FL AND 18Z
MESOANALYSIS/WEBCAMS INDICATE THAT MARITIME TROPICAL AIR MASS HAS
SPREAD INLAND PAST THE KEYS AND INTO INLAND MONROE/BROWARD COUNTIES.
 CONTINUED HEATING SHOULD ALLOW THE WARM FRONT TO JUMP TO
NAPLES-NORTH OF VERO BEACH LINE BY 21Z.  18Z SPECIAL RAOBS FROM
KMFL/KEYW PORTRAY THE BOUNDARY LAYER MOISTURE INCREASE WELL AND AIR
MASS HAS CONTINUED TO DESTABILIZE WITH CURRENT MLCAPES 1000-1500
J/KG.  MIDLEVEL LAPSE RATES ARE SOMEWHAT POOR...AND SUGGESTS THAT
WARM SECTOR CUMULUS DEVELOPING VCNTY WARM FRONT ATTM MAY TAKE A
WHILE TO GROW INTO TSTMS.  BUT...ISOLD TSTMS CANNOT BE RULED OUT THE
REMAINDER OF THE AFTERNOON.

18Z SOUNDINGS ALSO INDICATED THAT THE LOW/DEEP LAYER SHEAR HAS
BECOME FAVORABLE FOR SUPERCELLS GIVEN A STORM. THE LOW LEVEL FLOW
SHOULD ONLY INCREASE INTO THE EVENING AND GIVEN INFLUX OF RICH
TROPICAL AIR MASS...TORNADOES WILL BE POSSIBLE WITH ANY TSTMS THAT
FORMS...PARTICULARLY ALONG THE WARM FRONT.

OTHERWISE...LARGE COMPLEX OF TSTMS 140 NM WEST OF NAPLES IS MOVING
EWD AT 30 KTS AND EXTRAPOLATION HAS THIS MCS TO THE SWRN FL COAST BY
22-23Z.  VSBL SATELLITE SHOWS CONVECTIVE ELEMENTS DEVELOPING SWD
ALONG A PRE-FRONTAL TROUGH AND THESE ARE LIKELY TO MATURE INTO TSTMS
BY EVENING.  THUS...EXPECT THAT A LINEAR MCS WILL EVOLVE AND MOVE
EWD SWRN FL WITH DAMAGING WIND POTENTIAL INCREASING AFTER 22-23Z. 
SUPERCELLS MAY DEVELOP AHEAD OF THIS LINE AS WELL WITH THREATS FOR
ISOLD TORNADOES.

..RACY.. 12/25/2004

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

ATTN...WFO...MFL...MLB...TBW...

26157994 25818029 25558069 25318136 25588182 26188211
26538207 27128131 27698037 27147990 

WWWW