[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 130603
SWODY1
SPC AC 130601

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0101 AM CDT WED OCT 13 2004

VALID 131200Z - 141200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 15 SE
CHS 10 WNW CAE 10 NNE SPA 15 NW HKY 25 W DAN 35 SW RIC 25 NE ORF.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 35 ESE SAV 35 SSW AHN
35 SSE CSV 35 NE SDF 10 NNW DAY 15 NE FKL 25 NE IPT 25 ESE NEL.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 E DUG 35 WNW SAD
15 NNW SOW 30 NNW GUP 25 SE 4SL 40 SSE 4CR 20 E HOB 30 ESE ACT 15
SSE POE 35 W BVE.

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE CAROLINAS
INTO FAR SERN VA...

...SYNOPSIS...
PROGRESSIVE UPPER FLOW WILL CONTINUE TO DEVELOP ACROSS THE U.S.
TODAY AS A STRONG...COLD UPPER TROUGH DIGS SSEWD ACROSS THE PLAINS
STATES CARVING OUT A LONG WAVE TROUGH OVER THE PLAINS TO MS VALLEY. 
DOWNSTREAM HEIGHT FALLS WILL STRENGTHEN THE SRN STREAM OVER SRN TX
TO THE GULF COAST STATES.  CLOSED UPPER LOW...CURRENTLY CENTERED
OVER THE MID MS VALLEY WILL BECOME AN OPEN WAVE AS IT TAKES ON A
NEGATIVE TILT TRACKING NE TOWARD THE UPPER OH VALLEY/MID ATLANTIC
REGION.  DEEPENING SURFACE LOW ASSOCIATED WITH THIS UPPER SYSTEM
WILL MOVE NEWD ACROSS OH TO THE LOWER GREAT LAKES REGION THIS
PERIOD.  DOWNSTREAM HEIGHT FALLS ACROSS THE CAROLINA PIEDMONT WILL
IN TURN INDUCE SURFACE CYCLOGENESIS IN THIS AREA.

IN THE CENTRAL STATES...A STRONG COLD FRONT ASSOCIATED WITH THE
DIGGING UPPER TROUGH IS EXPECTED TO EXTEND FROM THE UPPER MS VALLEY
TO THE OK/TX PANHANDLE REGION AT THE START OF THE PERIOD.  THIS
FRONT WILL THEN SURGE SSEWD REACHING THE LOWER MS VALLEY TO DEEP S
TX BY 12Z THURSDAY. 

...CAROLINAS INTO SERN VA...
SURFACE BOUNDARY EXTENDING E-W ACROSS NC WILL MOVE NWD AS A WARM
FRONT TO THE VA/NC BORDER TODAY...AND THEN NEWD AS THE DEVELOPING
PIEDMONT SURFACE LOW DEEPENS AND TRACKS TOWARD THE DELMARVA REGION
TONIGHT.  WARM MID-LEVEL AIR /IN 700-500 MB LAYER PER FORECAST
SOUNDINGS/ AND SOME CLOUDINESS LIMITING SURFACE HEATING WILL RESULT
IN WEAK LAPSE RATES.  HOWEVER...INCREASING MOISTURE RETURN AS
LOW-LEVEL SSWLY WINDS STRENGTHEN TO 30 KT SHOULD SUPPORT MODERATE
INSTABILITY /MLCAPE 1000-1500 J/KG/ BY AFTERNOON.  50 KT WLY
MID-LEVEL SPEED MAX CURRENTLY OVER THE LOWER MS VALLEY WILL
TRANSLATE EWD ACROSS THE SERN STATES WITH LARGE SCALE ASCENT IN THE
LEFT EXIT REGION SPREADING OVER THE SLIGHT RISK AREA.  

THUNDERSTORMS ARE EXPECTED TO BE ONGOING OVER PORTIONS OF VA/NC WITH
THIS ACTIVITY RE-INTENSIFYING BY EARLY AFTERNOON AND/OR NEW TSTM
DEVELOPMENT EXPECTED IN THE WARM SECTOR AND ALONG WARM FRONT IN THE
CAROLINAS.  INCREASING DEEP LAYER SHEAR TO 30-40 KT WILL SUPPORT
ORGANIZED STORMS WITH EMBEDDED SUPERCELLS LIKELY.  THE GREATEST
POTENTIAL FOR SEVERE STORMS WILL BE ACROSS CENTRAL AND ERN PORTIONS
OF THE CAROLINAS WHERE MODELS SUGGEST THE POTENTIAL FOR STRONGER
SURFACE HEATING AND SUBSEQUENT GREATER INSTABILITY.
WEAK LAPSE RATES WILL PRECLUDE A HAIL THREAT...BUT DAMAGING WINDS
WILL BE LIKELY.  SOME BACKING OF LOW-LEVEL WINDS TO THE EAST OF THE
SURFACE LOW AND NEAR THE WARM FRONT WILL INCREASE LOW-LEVEL SHEAR
FOR AN ENHANCED TORNADO POTENTIAL.

SWLY LLJ IS PROGGED TO STRENGTHEN TO 40 KT ALONG THE SC/NC COAST 
THIS EVENING...AND COMBINED WITH MODERATE INSTABILITY/STRONG DEEP
LAYER SHEAR SHOULD SUPPORT A CONTINUATION OF SEVERE STORMS OVER ERN
NC AFTER DARK. 

...S TX...
HEIGHT FALLS IN ADVANCE OF THE DIGGING CENTRAL STATES UPPER TROUGH
WILL RESULT IN DEVELOPING SLY WINDS ACROSS S TX TODAY. THIS WILL
SUPPORT A RETURN OF HIGHER SURFACE DEWPOINTS INTO THIS AREA. 
COMBINED WITH SURFACE HEATING AND STEEPENING LAPSE RATES...THIS WILL
LIKELY SUPPORT MODERATE INSTABILITY BY AFTERNOON.  MODELS SUGGEST
ISOLATED STORMS ARE POSSIBLE IN THIS AIR MASS AHEAD OF THE SWD
MOVING COLD FRONT.  GIVEN MODERATE INSTABILITY AND INCREASING DEEP
LAYER SHEAR...ISOLATED MARGINAL SEVERE WILL BE POSSIBLE. WEAK
LOW-LEVEL WIND FIELDS WILL PRECLUDE A TORNADO THREAT...BUT LOW
PROBABILITIES FOR WIND AND HAIL ARE FORECAST.

A GREATER THREAT FOR THUNDERSTORMS IS EXPECTED LATER THIS EVENING
AND OVERNIGHT AS THE STRONG COLD FRONT MOVES SWD INTO THE MOIST/
UNSTABLE AIR MASS FROM DRT-HOU AND SWD.  THIS ACTIVITY SHOULD MAINLY
BE POST-FRONTAL WITH ELEVATED MODERATE INSTABILITY AND STRONG DEEP
LAYER SHEAR SUPPORTING AN ISOLATED HAIL THREAT.

THUNDERSTORMS WILL ALSO BE POSSIBLE OVER SWRN TX INTO SRN NM WITHIN
POST-FRONTAL UPSLOPE FLOW REGIME.  WEAK INSTABILITY IS EXPECTED TO
PREVENT A SEVERE THREAT THIS FAR WEST.

..PETERS/CROSBIE.. 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.