[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 132010
SWODY1
SPC AC 132008

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0308 PM CDT WED OCT 13 2004

VALID 132000Z - 141200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 30 ESE
CRP ALI 60 WNW COT DRT 60 SE MAF 45 E BGS BWD TPL 35 SW GLS.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 ESE DUG 45 WSW SAD
INW 10 SSW CEZ MTJ GUC LVS 40 E DHT MWL LFK 40 ESE 7R4.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM CRE 5I3 20 N CMH CLE
BUF IPT ACY.

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS SW AND S-CENTRAL TX...

...SYNOPSIS...
PROGRESSIVE UPPER AIR PATTERN IS EVOLVING TOWARD DEEP ERN CONUS
TROUGH AND MAINTAINING LONGWAVE RIDGE OFF W COAST.  INITIAL TROUGH
-- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER OH VALLEY - IS FCST
TO DEAMPLIFY GRADUALLY AS IT MOVES INTO CENTRAL APPALACHIANS AND MID
ATLANTIC REGION THROUGH REMAINDER PERIOD.  IN RESPONSE...WEAK SFC
LOW HAS FORMED AT OCCLUSION TRIPLE POINT -- OVER WRN NC -- AND
SHOULD MOVE ENEWD ACROSS VA BORDER TOWARD SRN CHESAPEAKE BAY REGION
THROUGH THIS EVENING.  WARM FRONT SHOULD LIFT NWD THROUGH HAMPTON
ROADS AREA BEFORE SFC LOW ARRIVES.  SFC COLD FRONT WILL MOVE EWD
ACROSS CAROLINAS -- CHARACTERIZED MORE BY VEERED SFC FLOW AND DRY
ADVECTION THAN BY SUBSTANTIAL COOLING. TRAILING PORTION OF THIS
FRONT BECOMES DIFFUSE OVER NRN FL AND NERN CENTRAL GULF...AND
APPEARS TO BE RETREATING NEWD AS SUBTLE WARM FRONT OVER S-CENTRAL TX
AND MIDDLE TX COAST.

FARTHER W...MID/UPPER TROUGH OVER CENTRAL HIGH PLAINS AND UPPER
MIDWEST WILL STRENGTHEN CONSIDERABLY TONIGHT AS IT DIGS SSEWD TOWARD
ERN KS...MO AND ERN OK.  ASSOCIATED SFC COLD FRONT -- ANALYZED FROM
SRN MO SWWD TO SERN NM -- WILL INTENSIFY TONIGHT AS IT SWEEPS SEWD
INTO NWRN GULF.

...SW/S TX...
SEVERAL MODES OF MARGINAL SEVERE POTENTIAL ARE POSSIBLE ACROSS
OUTLOOK AREA THROUGH REMAINDER PERIOD WHICH -- IN AGGREGATE -- WILL
BUILD SEVERE PROBABILITIES ENOUGH TO COMPEL CATEGORICAL SLGT RISK.

FIRST...ONGOING CONVECTION IN RELATIVELY WEAKLY CAPPED AIR MASS
ACROSS MID TX COAST IS IN ENVIRONMENT OF INCREASING BOUNDARY LAYER
THETAE -- NEAR EDGE OF MODIFYING MARINE AIR.  AS CAP WEAKENS WITH
CONTINUED HEATING FARTHER W...AND BUOYANCY INCREASES...THIS ACTIVITY
MAY BUILD WWD THROUGH AFTERNOON OVER PORTIONS S-CENTRAL TX IN
ENVIRONMENT OF STRENGTHENING MID/UPPER LEVEL FLOW...SUPPORTING
ORGANIZED MULTICELL MORPHOLOGIES.  STORM-SCALE BOUNDARY INTERACTIONS
ALSO MAY ENHANCE SEVERE POTENTIAL LOCALLY.  ISOLATED DAMAGING GUSTS
OR MARGINAL SEVERE HAIL IS POSSIBLE.

SECOND...WIDELY SCATTERED TSTMS MAY DEVELOP IN SOMEWHAT DRIER AIR
MASS OVER SRN HILL COUNTRY AND ADJACENT PORTIONS S-CENTRAL TX...AS
HEATING/MIXING CONTINUE FOR REMAINDER AFTERNOON AND CAP WEAKENS. 
THOUGH MIDLEVEL LAPSE RATES ARE NOT PARTICULARLY STRONG AT AROUND 7
DEG C/KM...EXPECT PREFRONTAL THETAE INCREASE TO RESULT IN MLCAPES
1000-1500 J/KG.  ENVIRONMENTAL SHEAR ALSO IS EXPECTED TO INCREASE
OVER THIS AREA...ENHANCING STORM ORGANIZATION DESPITE WEAK BOUNDARY
LAYER WINDS.  GIVEN ANTICIPATED STRENGTH AND PROGRESSION OF
BAROCLINIC ZONE...EXPECT EFFECTIVE ANAFRONTAL SITUATION WHERE ANY
CONVECTION DEVELOPING ALONG OR JUST AHEAD OF SFC BOUNDARY IS QUICKLY
UNDERCUT...BECOMING ELEVATED WITH LARGE HAIL AS MAIN THREAT.

FINALLY...MODELS REASONABLY PERSIST IN FORECASTING CONCENTRATED AREA
OF CONVECTION TONIGHT ACROSS S-CENTRAL TX AND MIDDLE TX COAST REGION
-- DEVELOPING INVOF SFC COLD FRONT AND PERHAPS PERSISTING BEHIND IT.
 THIS MAY EITHER BE CONTINUATION/EXTENSION OF AFTERNOON TSTMS OR
ADDITIONAL DEVELOPMENT WITH APCH OF FRONT.  IN EITHER EVENT MUCAPES
1000-2000 J/KG AND 40-50 KT DEEP LAYER SHEARS SHOULD  COUNTERACT
DETRIMENTAL EFFECTS OF WEAK BOUNDARY LAYER FLOW ENOUGH FOR AT LEAST
MARGINAL THREAT OF SEVERE WIND/HAIL IN THIS ROUND OF CONVECTION AS
WELL.  LARGE NUMBER OF TSTMS MAY RESULT IN CLUSTER OF SEVERE EVENTS
EVEN IF ONLY SMALL PERCENTAGE OF STORMS REACH THAT LEVEL.

...ERN NC...
SEVERE POTENTIAL HAS NOT VANISHED ALTOGETHER BUT IS DECLINING ACROSS
THIS REGION AS BULK OF WARM FRONTAL CONVECTION MOVES OUT TO SEA. 
STRONGEST VERTICAL SHEAR PROFILES WILL REMAIN INVOF SFC WARM FRONT
LIFTING NWD FROM NRN NC.  HOWEVER...BOTH SFC CONVERGENCE AND
BUOYANCY ARE NOT AS FAVORABLE INLAND AS OFFSHORE BECAUSE OF STRONGLY
VEERED FLOW AND DRYING S OF WARM FRONT.  WILL MAINTAIN MARGINAL
SEVERE WIND/TORNADO PROBABILITIES INVOF WARM FRONT FOR REMAINDER
AFTERNOON...AND DROP CATEGORICAL OUTLOOK.

..EDWARDS.. 10/13/2004

...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.