[MCD] SWOMCD

Sat Nov 26 16:07:41 UTC 2005

ACUS11 KWNS 261605
SWOMCD
SPC MCD 261605 
LAZ000-TXZ000-261830-

MESOSCALE DISCUSSION 2467
NWS STORM PREDICTION CENTER NORMAN OK
1005 AM CST SAT NOV 26 2005

AREAS AFFECTED...COASTAL SE TX...PORTIONS SWRN/S-CENTRAL LA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 261605Z - 261830Z

SLGT POTENTIAL FOR SEVERE WILL DEVELOP ALONG COASTAL AREAS BETWEEN
GLS-LFT THROUGH EARLY AFTERNOON...WITH A TORNADO OR TWO POSSIBLE
ALONG WITH ISOLATED DAMAGING WIND.

SFC MESOANALYSIS SHOWS WEAK FRONTAL-WAVE LOW OFFSHORE PORT MANSFIELD
TX.  COMBINED FRONTAL ZONE AND OUTFLOW/CONVECTIVE BOUNDARY EXTENDS
NEWD TOWARD GLS...THEN MARINE/WARM FRONT IS ANALYZED JUST OFFSHORE
FROM CHAMBERS COUNTY EWD ACROSS COASTAL WATERS CAMERON/VERMILION/ST
MARY/IBERIA PARISHES.  LOOSELY ORGANIZED MCS ALONG AND BEHIND
OUTFLOW BOUNDARY WILL CONTINUE TO MOVE EWD ACROSS COASTAL AREAS
THROUGH AFTERNOON.  MARINE FRONT SHOULD DRIFT NWD INTO EARLY
AFTERNOON AND MAY MOVE ONSHORE BRIEFLY BEFORE LEADING EDGE OF MCS
MOVES THROUGH. MODIFIED RAOBS AND RUC SOUNDINGS INDICATE SFC-BASED
BUOYANCY ALONG AND S OF MARINE FRONT GIVEN AND DEW POINTS MID 60S
NOW OBSERVED IN THAT AIR MASS...AND COMBINED WAA/INSOLATION RELATED
HEATING OF SFC TEMPS INTO LOW 70S.
STRONGER LARGE SCALE FORCING/ASCENT REMAINS ALONG/BEHIND OUTFLOW
BOUNDARY...SO LAPSE RATES OVER MARINE AIR SHOULD REMAIN
WEAK....LIMITING MLCAPES UNDER 750 J/KG MOST AREAS.  PARCELS N OF
WARM FRONT WILL REMAIN SLIGHTLY ELEVATED BECAUSE OF PRONOUNCED
STABLE LAYER NEAR SFC...KEEPING SEVERE POTENTIAL LARGELY ALONG/S OF
FRONT.

DEEP-LAYER SPEED SHEAR -- NOW OPTIMIZED ACROSS UPPER TX COAST PER
VWP/PROFILER DATA AND RUC ANALYSES -- WILL INCREASE WITH TIME
FARTHER E ACROSS SWRN/S-CENTRAL LA AS MID/UPPER LEVEL PERTURBATION
APCHS. ALTHOUGH HODOGRAPH SIZE IS LIMITED BY LACK OF DIRECTIONAL
SHEAR IN LOW LEVELS...CELLS MAY ROTATE.  SUSTAINED SUPERCELL
PROBABILITIES ARE HIGHER FOR TSTMS MOVING ONSHORE FROM GULF THAN EWD
IN MCS BECAUSE OF SOMEWHAT MORE DISCRETE MODE.

..EDWARDS.. 11/26/2005

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

ATTN...WFO...LCH...HGX...

28339545 29049506 29689460 30009391 29929233 29729162
29479147 29319163 29169204 29059304 28789396 28149486 

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