[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 212004
SWODY1
SPC AC 212003

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0203 PM CST TUE DEC 21 2004

VALID 212000Z - 221200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 25 S
PSX 60 NNE VCT CLL LFK POE LFT 45 SSE 7R4.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 SSE CRP COT SAT
AUS PGO 45 ESE HRO CGI PAH TUP 15 SW PNS.

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS SE TX AND WRN LA...

...SYNOPSIS...
LONGWAVE TROUGH FROM HUDSON BAY TO NRN MEX WILL CONTINUE TO AMPLIFY
THROUGH REMAINDER PERIOD AND INTO DAY-2...REINFORCED BY 150 KT 300
MB JET MAX NOW DIGGING SWD ACROSS NRN ROCKIES. MEANWHILE...LEADING
EDGE OF SERIES OF ARTIC AIR SURGES IS NOW ANALYZED AS A COLD FRONT
FROM LOWER MI SWWD ACROSS ERN MO...THROUGH WEAK FRONTAL-WAVE LOW
OVER N-CENTRAL TX...THEN WSWWD ACROSS LOWEST PECOS VALLEY REGION. 
THIS FRONT SHOULD MOVE SEWD THROUGH REMAINDER PERIOD...WITH LOW
SHIFTING EWD INTO ARKLATEX REGION.

...SE TX...WRN LA...
STRONG LOW LEVEL WAA/ISENTROPIC LIFT REGIME WILL CONTINUE SE OF
FRONT...DESTABILIZING AIR MASS AND CONTRIBUTING TO POTENTIAL FOR
SEVERE WIND/HAIL NEAR COAST.  A TORNADO OR TWO CANNOT BE RULED OUT
EITHER...GIVEN INCREASING SHEAR PROFILES PROGGED.

SFC MESOANALYSIS SHOWS CONFLUENCE LINE FROM TYR AREA SWD ACROSS HOU
METRO INTO GULF...TO ABOUT 45 E BRO...THEN SWD PARALLEL TO MEX
COAST...MOVING E 10-15 KT.  RAOB ANALYSIS AND MODIFIED RUC SOUNDINGS
ALSO INDICATE THIS LINE NEARLY COINCIDES WITH ERN EDGE OF STRONGEST
CAPPING EVIDENT IN 12Z CRP/BRO/DRT AND MONTERREY RAOBS.  LOW LEVEL
CONVERGENCE AND CONVECTIVE COVERAGE SHOULD REMAIN GREATEST FOR
REMAINDER AFTERNOON INTO EARLY EVENING ALONG AND WITHIN ABOUT 80 NM
E OF THIS LINE...WHICH SHOULD BECOME QUASISTATIONARY AND PERHAPS
RETREAT SLIGHTLY AMIDST CONTINUED PREFRONTAL PRESSURE/HEIGHT FALLS. 
AIR MASS OVER LAND CONTINUES TO DESTABILIZE NEAR SFC WITH 500-1000
J/KG MLCAPE EXPECTED ACROSS MOST OF CATEGORICAL SLGT RISK FOR
REMAINDER AFTERNOON.  LARGEST HODOGRAPHS WILL REMAIN IN AREA OF
RELATIVELY BACKED FLOW E OF CONFLUENCE LINE...WHERE 200-300 SRH IS
LIKELY IN SFC-3 KM LAYER.  VWP DATA SHOWS FAVORABLE LOW LEVEL
HODOGRAPHS FOR SUPERCELLS GIVEN STRONG RIGHTWARD MOTION -- SUCH AS
THAT OBSERVED SINCE 16Z WITH SUPERCELL ABOUT 60-70 NM OFFSHORE GLS.

SUBSTANTIAL INCREASE IN CONVECTIVE COVERAGE EXPECTED LATE TONIGHT
OVER TX COASTAL PLAIN AND SW LA...AMIDST INCREASINGLY MOIST LOW
LEVEL AIR MASS.  ALTHOUGH GREAT MAJORITY OF CONVECTION SHOULD REMAIN
AHEAD OF SFC COLD FRONT...WIDELY SCATTERED TSTMS MAY DEVELOP OVER
PORTIONS S TX AND MID TX COASTAL PLAIN...ALONG AND JUST BEHIND
FRONT...AFTER ABOUT 06Z.  DEEP-LAYER VERTICAL SHEAR PROFILES SHOULD
INCREASE GRADUALLY THROUGH REST OF PERIOD AS MEAN TROUGH
AMPLIFIES...ENHANCING GRADIENT FLOW ALOFT AND POTENTIAL FOR SEVERE
THROUGH TONIGHT.

..EDWARDS.. 12/21/2004

...NOTICE...
FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3.  THE
INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.