[SWODY2] SWODY2

[SWODY2 at goshenarc.org]

ACUS02 KWNS 121734
SWODY2
SPC AC 121733

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1233 PM CDT TUE OCT 12 2004

VALID 131200Z - 141200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 35 E
SAV 35 E AGS 40 N CAE 30 NNW SOP RWI HSE.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM ELP GDP BWD TPL CLL
GLS.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 SSE SAV AGS AHN 55
WNW CHA OWB DAY CLE FKL DUJ PSB ACY.

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS ERN CAROLINAS...

...SYNOPSIS...
DAY-2 WILL BE CHARACTERIZED BY RAPIDLY EVOLVING UPPER AIR PATTERN AS
 MEAN TROUGH BEGINS TAKING SHAPE OVER ERN NORTH AMERICA...AND LOW
NOW MOVING OFFSHORE SRN CA RETROGRADES AND BECOMES CUT OFF. 
SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER
CANADIAN PLAINS -- IS FCST TO DIG SEWD AND STRENGTHEN
CONSIDERABLY...EVOLVING INTO PROGRESSIVE AND NEARLY CLOSED LOW OVER
ERN OK BY END OF PERIOD.  AS THIS OCCURS...ASSOCIATED BELT OF
SHARPLY CYCLONIC FLOW ALOFT SHOULD CONTAIN 70-80 KT 500 MB SPEED MAX
AND 250 MB JET LIKELY EXCEEDING 120 KT.  MEANWHILE...MID/UPPER LOW
PRESENTLY OVER OZARKS REGION IS EXPECTED TO EVOLVE INTO OPEN
SHORTWAVE TROUGH AND MOVE FROM LOWER OH VALLEY TO VICINITY
WV/VA/TIDEWATER AREA BY 14/12Z.

AT SFC...FRONTAL-WAVE LOW SHOULD DEVELOP OVER SC AHEAD OF ERN CONUS
MIDLEVEL TROUGH...ALONG PIEDMONT BAROCLINIC ZONE...AND MOVE NEWD
TOWARD NERN NC/SERN VA.  PROGRESSIVE AND STRENGTHENING COLD FRONT
SHOULD SURGE SEWD ACROSS SRN PLAINS AND INTO EXTREME NWRN GULF BY
END OF PERIOD.

...CAROLINAS/SERN VA REGION...
SCATTERED TSTMS ARE LIKELY ACROSS MUCH OF COASTAL PLAIN AND
TIDEWATER REGION FROM SERN VA TO SC...AND INLAND ONTO PORTIONS
CAROLINAS PIEDMONT.  STRONGEST LOW LEVEL CONVERGENCE AND
JUXTAPOSITION OF FAVORABLE INSTABILITY/SHEAR SHOULD BE BETWEEN
13/18Z AND 14/03Z OVER CATEGORICAL SLGT RISK AREA -- BEHIND INITIAL
ROUND OF CONVECTION PROGGED BY ETA/SPECTRAL.  VERTICAL SHEAR
PROFILES SHOULD INCREASE ACROSS REGION WITH APCH OF OH VALLEY TROUGH
ALOFT...AND ISALLOBARIC SFC RESPONSE TO PIEDMONT FRONTAL-WAVE
CYCLOGENESIS.  RESULTING BACKED FLOW AHEAD OF SFC LOW WILL
CONTRIBUTE TO 0-1 KM SRH 100-200 J/KG...AND 0-6 KM AGL SHEARS 40-50
KT.  DIURNAL HEATING BEHIND EARLY CLOUDS/PRECIP SHOULD OVERCOME
MODEST LAPSE RATES ALOFT TO YIELD 1000-1500 J/KG AFTERNOON MLCAPE IN
NARROW CORRIDOR AHEAD OF SFC CONVERGENCE AXIS.
BOTH SUPERCELLULAR AND BOW ECHO MODES ARE POSSIBLE WITH THIS
ACTIVITY...DAMAGING GUSTS EXPECTED ALONG WITH POTENTIAL FOR A FEW
TORNADOES.  SHORTER OPPORTUNITY FOR DESTABILIZATION MAKES OUTLOOK
MORE CONDITIONAL WITH NEWD EXTENT INTO SERN VA.

...S TX...
ISOLATED TO WIDELY SCATTERED TSTMS POSSIBLE DIURNALLY ALONG/AHEAD OF
SFC COLD FRONT AS COOLING ALOFT...LOW LEVEL THETAE ADVECTION...AND
SFC DIABATIC HEATING COMBINE TO WEAKEN CAP AND RAISE MLCAPES TO
1000-2000 J/KG RANGE.  AIR MASS WILL BE CHARACTERIZED BY INCREASING
LOW-MIDLEVEL LAPSE RATES ABOVE BOUNDARY LAYER...INCREASING
DEEP-LAYER SHEAR...BUT WEAK LOW LEVEL FLOW.  THIS RESULTS IN
RELATIVELY SMALL FCST HODOGRAPHS -- EXCEPT FOR EXTREMELY DEVIANT
STORM MOTIONS -- AND 40-50 KT SHEAR THROUGH 0-6 KM AGL LAYER.  MAIN
CONCERN IS EXTENT OF AIR MASS RECOVERY GIVEN UPPER 50S TO MID 60S F
SFC DEW POINTS AND NLY FLOW COMPONENTS NOW EVIDENT OVER
AREA...HOWEVER TRAJECTORY LENGTHS FOR RICHER MOISTURE OVER NW GULF
WILL BE RATHER SHORT.  TSTMS ALSO SHOULD INCREASE IN COVERAGE
THROUGH WEDNESDAY NIGHT ON BOTH SIDES OF SFC COLD FRONT...ACROSS S
TX...AS INTENSIFYING UPPER TROUGH APCHS.  HAIL MAY OCCUR FROM
STRONGER CELLS BOTH AHEAD OF AND BEHIND FRONT...AND ISOLATED
STRONG-SEVERE GUSTS ARE POSSIBLE ALONG/AHEAD OF FRONT WHERE BOUNDARY
LAYER HAS NOT BEEN STABILIZED TOO MUCH BY CAA. SOME OF THIS AREA
MAY REQUIRE CATEGORICAL SEVERE OUTLOOK.

..EDWARDS.. 10/12/2004

...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.