ZCZC SPCSWODY1 ALL
ACUS01 KWNS 180603
SPC AC 180603

STORM PREDICTION CENTER...NWS/NCEP...NORMAN OK 
DAY 1 CONVECTIVE OUTLOOK...REF AWIPS GRAPHIC PGWE46 KWNS.

VALID 181200Z - 191200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM
20 SE SBY 35 WSW RIC 30 W AVL 25 SSE TYS 25 NNW TYS 30 NW CSV
60 WSW BNA MEM 45 WSW JBR 30 SSW UNO 40 SW IRK 30 NNW IRK
35 NW BRL 10 NW HUF 25 E CMH 10 SSE PSB 30 SSW MSV 10 SW EWB.

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM
40 WNW RRT 25 SE JMS 40 ESE PHP 25 NNW EAR 15 ESE IML 35 E CYS
45 WSW GCC 25 SE COD 50 NW COD 20 SSE 3HT 60 NNW ISN.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM CZZ 40 ENE PRB
35 SE RBL 15 NNW SVE 30 SE LOL 30 WNW MLD 35 NNW PIH 60 SW 27U
35 NW BNO 55 SW PDT 35 WSW FCA 35 SSW CTB 40 SW HVR 70 W GGW
50 N GGW ...CONT... 70 E ELO 50 ESE BRD 20 NE MKT 50 NNE ALO
35 E DBQ 25 SSE CGX 35 NE FWA 15 SSE CLE 25 NE FKL 10 NW UCA
25 NW PBG ...CONT... 40 SE DRT 30 N TYR 45 SSE PGO 15 ENE FYV
35 NNE CNU 25 NW MHK 30 NNE HLC 45 WSW GLD 25 WSW LHX 35 NNE LVS
50 ENE 4CR 35 SE ROW 30 NW FST 75 S MRF.



...SYNOPSIS...

THE UPPER TROUGH NOW OVER WRN CANADA WILL MOVE ESEWD INTO CNTRL
CANADA...FLATTENING CREST OF UPPER RIDGE OVER NRN PLAINS FRIDAY. A
COLD FRONT WILL ACCOMPANY THIS FEATURE AND BY LATE AFTERNOON SHOULD
EXTEND FROM WRN ND SWWD THROUGH ERN MT. BROAD UPPER TROUGH OVER THE
ERN U.S. WILL CONTINUE TO AMPLIFY AS ANOTHER IN A SERIES OF
SHORTWAVE TROUGHS DROPS SEWD INTO THE GREAT LAKES/OH VALLEY AREA.
AS THIS OCCURS THE E-W SURFACE BOUNDARY CURRENTLY FROM THE NERN
U.S. SWWD THROUGH CNTRL NEB WILL SHIFT SWD AND BY LATE AFTERNOON IS
FORECAST TO EXTEND FROM KS EWD INTO THE MID ATLANTIC AREA.

...CNTRL/NRN PLAINS...

THE ATMOSPHERE WILL AGAIN BECOME VERY UNSTABLE OVER MUCH OF THE
PLAINS WITH MLCAPES FROM 3000 TO 4000 J/KG. CAP MAY ONCE AGAIN
PRESENT A PROBLEM FOR INITIATION OVER MUCH OF THIS AREA. BEST
CHANCE FOR STORMS SHOULD BE ALONG THE FRONT FROM ERN MT INTO WRN ND
AND OVER THE HIGHER TERRAIN IN WEAK UPSLOPE REGIME ACROSS SRN MT
AND INTO WY. ANY STORMS DEVELOPING IN VICINITY OF FRONT ACROSS ERN
MT INTO ND WILL BE WITHIN A STRONGER FLOW REGIME ALONG NRN
PERIPHERY OF UPPER RIDGE WHERE SHEAR WILL BE SUPPORTIVE OF
SUPERCELLS. HOWEVER...GIVEN LARGE SCALE ASCENT ASSOCIATED WITH THE
UPPER TROUGH REMAINING N OF THE U.S. BORDER AND EXPECTED WEAK LOW
LEVEL FLOW...FORCING FOR INITIATION ALONG THE FRONT MAY NOT BE
PARTICULARLY STRONG. ACTIVITY DEVELOPING OVER THE HIGHER TERRAIN
WILL LIKELY CONTINUE EWD INTO THE WRN PLAINS AS HIGH BASED STORMS
WHERE BOUNDARY LAYER MAY UNDERGO DEEPER MIXING. SHEAR PROFILES WILL
BE WEAKER FARTHER S. HOWEVER...SUFFICIENT LOW LEVEL DRY AIR SHOULD
BE AVAILABLE FOR COLD POOL ENHANCEMENT. ISOLATED DAMAGING WIND AND
HAIL WILL BE THE MAIN THREATS. ACTIVITY WILL ENCOUNTER STRONGER CAP
WITH TIME AS IT CONTINUES EWD INTO THE PLAINS...BUT MAY EVENTUALLY
BECOME ELEVATED OVERNIGHT IN ZONE OF WARM ADVECTION ASSOCIATED WITH
DEVELOPING LOW LEVEL JET.


...MID MS VALLEY THROUGH OH VALLEY AND MID ATLANTIC AREA...

ATMOSPHERE S OF FRONT DROPPING SWD FROM THE MID ATLANTIC WWD INTO
THE MID MS VALLEY SHOULD BECOME MODERATELY UNSTABLE...WITH STRONGER
INSTABILITY EXPECTED OVER THE MID MS VALLEY IN ASSOCIATION WITH
STEEPER LAPSE RATES. STORMS MAY REDEVELOP ALONG OR S OF THE
BOUNDARY AS THE ATMOSPHERE DESTABILIZES. OUTFLOW FROM ONGOING
CONVECTION OVER THE OH VALLEY MAY ALSO PROVIDE A FOCUS FOR
CONVECTIVE INITIATION. SHEAR PROFILES WILL MAINLY BE SUPPORTIVE OF
MULTICELL CONVECTION. AN EXCEPTION WILL BE WITH ANY STORMS THAT CAN
DEVELOP AS FAR W AS THE MID MS VALLEY WHERE SELY LOW LEVEL FLOW
ABOVE NWLY FLOW ALOFT WILL CONTRIBUTE TO SHEAR SUFFICIENT FOR
SUPERCELLS. HOWEVER...WWD EXTENT OF DEVELOPMENT MAY BE LIMITED BY
STRONGER CAP. ISOLATED DAMAGING WIND AND HAIL WILL BE THE MAIN
THREATS THROUGH MID EVENING AS STORMS DEVELOP SEWD. ACTIVITY SHOULD
WEAKEN WITH LOSS OF HEATING.
 
..DIAL.. 07/18/03

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