ZCZC SPCSWODY1 ALL
ACUS01 KWNS 121300
SPC AC 121300

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0700 AM CST WED NOV 12 2003

VALID 121300Z - 131200Z

THERE IS A MDT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 35 NNE
ROC 30 SSW DUJ 20 WNW PKB 25 W LUK 25 SSW MIE 25 NE AZO 25 S MBS 70
NNE MTC.

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 30 NE
SBY 45 SW DCA 35 SW CRW 35 NW JKL 30 SSE OWB 10 SW EVV 15 ESE HUF 30
WSW BEH 10 WSW MKG 40 SE MBL 50 ENE OSC ...CONT... 10 NE MSS 40 WNW
GFL 25 NE MSV 15 SE ISP.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 SSW WAL 45 WSW RIC
25 W HSS 30 SE HSV 20 SSW CBM 45 S GLH 35 S ELD 50 SE PRX 35 NW PGO
20 ESE SGF 65 ESE VIH 15 NE MVN 20 WSW HUF 15 W LAF 35 S MKE 25 N
MSN 20 N LSE 40 NE MSP 10 SSE DLH ...CONT... 30 WNW EFK CON 25 NE
BOS.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 SSE VBG 15 WSW NID
30 E ELY 20 NE U24 20 N CNY 40 W FMN 55 NNW SVC 30 ESE DUG.

...THERE IS A MDT RISK OF SVR TSTMS ACROSS ERN IN...SERN MI...NRN
AND CENTRAL OH...WRN PA AND WRN NY...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE OH VALLEY
AND LOWER GREAT LAKES REGION TO THE MID-ATLANTIC COAST...

...SYNOPSIS...
STRONG MID-LEVEL TROUGH NOW OVER THE NRN PLAINS IS FORECAST TO
CONTINUE TO STRENGTHEN AS IS MOVES RAPIDLY EWD ACROSS THE OH VALLEY
/ GREAT LAKES REGION AND EVENTUALLY INTO THE NORTHEAST BY THE END OF
THE PERIOD.  VERY STRONG UPPER JET STREAK /110 TO 130 KT AT
MID-LEVELS/ IS FORECAST TO ACCOMPANY THIS TROUGH.

AT THE SURFACE...RAPIDLY-SHARPENING COLD FRONT IS ANALYZED ATTM FROM
NEAR THE IA / IL BORDER SWWD INTO CENTRAL OK...WITH DEEPENING /
OCCLUDING SURFACE LOW INVOF MPX.  THIS LOW IS FORECAST TO CONTINUE
DEEPENING AS IT MOVES EWD...REACHING THE OTTAWA RIVER VALLEY OF SRN
QUEBEC BY THE END OF THE PERIOD.  ASSOCIATED COLD FRONT WILL ALSO
MOVE RAPIDLY EWD...CROSSING THE OH VALLEY / APPALACHIANS AND
REACHING THE NEW ENGLAND / MID-ATLANTIC COASTAL REGION BY THE END OF
THE PERIOD.

...GREAT LAKES / OH VALLEY REGION EWD TO NJ...
MORNING ILX /CENTRAL IL/ RAOB SHOWS STEEP /6.8 C/KM/ 850 TO 500 MB
LAPSE RATES...AND SURFACE ANALYSIS SHOWS LOW-LEVEL MOISTURE
ADVECTING NWD INTO THE LOWER OH VALLEY AHEAD OF COLD FRONT. 
ALTHOUGH LITTLE INSTABILITY EXISTS ATTM...MARGINAL DESTABILIZATION
SHOULD CONTINUE THROUGH THE MORNING AND INTO THE AFTERNOON AHEAD OF
SURFACE BOUNDARY DESPITE LIMITED HEATING.  

THUNDERSTORMS ARE FORECAST TO DEVELOP BY MIDDAY ALONG AND AHEAD OF
COLD FRONT -- LIKELY OVER SRN LK MI / NRN IL -- AND THEN SWD ALONG
FRONT WITH TIME.  MORE ISOLATED SHOWERS / STORMS MAY ALSO DEVELOP IN
WEAK WARM ADVECTION AHEAD OF DEVELOPING LINE.

ALTHOUGH LIMITED INSTABILITY IS EXPECTED /MEAN-LAYER CAPE BELOW 500
J/KG/ THROUGH THE AFTERNOON...STRENGTH OF UPPER SYSTEM AND STRONG
LOW-LEVEL CONVERGENCE ALONG COLD FRONT SHOULD ALLOW STORMS TO
DEVELOP INTO A RAPIDLY-MOVING SQUALL LINE BY MID AFTERNOON.

WITH SOME LOW-LEVEL VEERING AND VERY STRONG DEEP-LAYER WIND
FIELD...ROTATING / SUPERCELL STORMS ARE EXPECTED TO BE EMBEDDED
WITHIN SQUALL LINE -- ALONG WITH THE POTENTIAL FOR A FEW ROTATING
STORMS AHEAD OF THE MAIN LINE. ANTICIPATED SPEED OF CONVECTIVE LINE
MOTION AND STRENGTH OF WIND FIELD SUGGESTS THAT WIDESPREAD DAMAGING
WINDS CAN BE EXPECTED -- WITH SOME POTENTIAL FOR LOCALLY MORE
SIGNIFICANT DAMAGE.  A COUPLE OF ISOLATED TORNADOES ARE ALSO
POSSIBLE ASSUMING A FEW CELLS CAN ORGANIZE ON THE STORM SCALE.

BY EVENING...CONVECTIVE LINE SHOULD BE APPROACHING WRN NY / ERN PA /
WV...WHERE INSTABILITY SHOULD BE EVEN MORE LIMITED. 
NONETHELESS...OVERALL STRENGTH OF FRONT AND ASSOCIATED UPPER SYSTEM
SUGGEST THAT LINE SHOULD REMAIN ORGANIZED AND CAPABLE OF PRODUCING
DAMAGING WINDS THROUGH MOST OF THE NIGHT.

...SRN CA / AZ / SRN NV / SRN UT...
MARGINAL INSTABILITY IS FORECAST ACROSS THIS REGION AS UPPER LOW AND
ASSOCIATED COLD POOL ALOFT MOVES NEWD INTO SRN NV BY THE END OF THE
PERIOD.  SCATTERED TO ISOLATED THUNDERSTORMS ARE FORECAST --
PARTICULARLY DURING THE AFTERNOON -- AS THIS FEATURE MOVES ACROSS
THE REGION.

SLIGHTLY GREATER INSTABILITY /250 TO 500 J/KG MEAN-LAYER CAPE/ MAY
DEVELOP ACROSS SRN CA AND INTO THE LOWER CO RIVER VALLEY THIS
AFTERNOON.  THIS SUGGESTS A LIMITED THREAT FOR MARGINALLY-SEVERE
HAIL WILL BE POSSIBLE WITH A COUPLE STRONGER STORMS ACROSS THIS
REGION...BUT OVERALL THREAT SHOULD REMAIN BELOW SLIGHT RISK
THRESHOLDS.

..GOSS / BANACOS.. 11/12/2003

...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.

$$