STORM PREDICTION CENTER...NWS/NCEP...NORMAN OK
DAY 1 CONVECTIVE OUTLOOK...REF AWIPS GRAPHIC PGWE46 KWNS.
VALID 172000Z - 181200Z
THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM
65 NW MOT 25 NW BIS 30 W ABR 25 W BKX 10 SSW OTG 30 NNE MCW
25 SSE LSE 25 SW OSC 55 E MBS 15 NW MTC 45 SE CGX 20 SSW DNV
10 NW SLO 45 W STL 20 WNW IRK 15 NNE OMA 45 ENE AIA 65 NE DGW
35 W 4BQ 55 WNW MLS 60 NNW GGW.
GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 10 SW LAX 35 WSW SAC
35 S RBL 50 ESE RBL 25 SSE LOL 35 SSE WMC 90 SE BNO 65 E BNO
30 NE CTB ...CONT... 70 NNE DVL 10 SSE FAR 40 WSW STC 35 NNW RST
35 NW OSH OSC ...CONT... 15 N CAR 45 E 3B1 35 W AUG 10 WNW LCI
15 NNE PSF 20 WSW POU 25 WNW ABE 35 E AOO MGW UNI 25 NNE LEX
35 WSW SDF 45 ENE PAH DYR 35 SSW MKL 30 SW MSL 35 N GAD 10 WSW TYS
30 E TRI 35 N GSO 30 WNW ORF 35 NE ORF.
GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 S PRX 30 W MKO
25 SE TOP 20 E BIE 30 N EAR 20 SW BBW 35 NE IML 30 SSE AKO
25 SSE PUB 40 ENE LVS 30 SW TCC 55 W LBB 35 SW ABI 15 S TPL
65 SSW TYR 15 S PRX.
...UPPER MS VALLEY EWD TO MI...
SHORT WAVE TROUGH DROPPING SSEWD FROM ONTARIO INTO THE WRN GREAT
LAKES ALONG WITH WEAK IMPULSES TOPPING THE RIDGE AND TRACKING SEWD
ACROSS THE UPPER MS VALLEY WILL RESULT IN HEIGHT FALLS ACROSS THIS
AREA OF CONCERN. WEAK SURFACE FRONT EXTENDED FROM NRN MI SWWD TO
SRN WI/NRN IA THIS AFTERNOON. AIR MASS ALONG/S OF MOST OF THIS
BOUNDARY HAS BECOME VERY UNSTABLE. DESPITE RATHER WEAK LOW-LEVEL
FLOW...40-50 KT OF NWLY MID-LEVEL WINDS WILL SUPPORT DEEP LAYER
SHEAR FOR ORGANIZED STORMS AND ISOLATED SUPERCELLS. ISOLATED
SEVERE STORMS WILL REMAIN POSSIBLE ACROSS MI THIS AFTERNOON...WHERE
THE AIR MASS IS MARGINALLY UNSTABLE. ADDITIONAL STORMS ARE
EXPECTED TO DEVELOP WSWWD ALONG THE COLD FRONT INTO SRN WI/NRN
IL...WITH THE THREAT OF LARGE HAIL AND DAMAGING WINDS. STORMS MAY
DEVELOP WWD INTO IA LATE THIS AFTERNOON OR EVENING...THOUGH
CONVECTION WILL BE FIGHTING A STRONG CAP.
SSEWD MOVING STORMS ACROSS IL/MI AND POTENTIALLY IA SHOULD WEAKEN
LATER THIS EVENING AS THE AIR MASS STABILIZES...THOUGH WEAK LOW-
LEVEL WAA ACROSS THE LOWER MO/MID MS VALLEYS IS EXPECTED TO SUPPORT
SUB-SEVERE STORMS OVERNIGHT.
...NRN HIGH PLAINS/NRN PLAINS...
EARLY AFTERNOON SURFACE ANALYSIS SHOWS SEVERAL WEAK CONVECTIVE
OUTFLOW BOUNDARIES EXTENDING FROM ERN MT ESEWD THROUGH SWRN/SRN ND
INTO NRN/ERN SD...WHILE THE PRIMARY SURFACE BOUNDARY EXTENDED WNWWD
FROM NWRN IA TO WRN SD AND ERN MT. SURFACE HEATING WILL CONTINUE
TO DESTABILIZE THE AIR MASS SOUTH AND EAST OF THESE BOUNDARIES...
WITH MLCAPES EXPECTED TO RANGE FROM 2500 J/KG OVER MT/SWRN ND TO
AROUND 3500 J/KG ACROSS SD BY LATE THIS AFTERNOON. SRN EXTENT OF
SHORT WAVE TROUGH MOVING THROUGH WRN CANADA EXTENDS SWD INTO NERN
MT. THIS FEATURE WILL AID IN CONTINUED CONVECTIVE DEVELOPMENT FROM
ERN MT INTO WRN/SWRN ND THIS AFTERNOON...WITH 45-55 KT OF DEEP
LAYER SHEAR SUPPORTING SUPERCELLS. ISOLATED TORNADOES WILL BE
POSSIBLE WITH THE INITIAL ACTIVITY. CELL MERGERS/STORM CLUSTERS
ARE EXPECTED TO EVOLVE INTO AN MCS LATER THIS EVENING/OVERNIGHT
WITH THE CONVECTIVE MODE BECOMING A DAMAGING WIND/HAIL THREAT AS
ACTIVITY PROPAGATES SEWD INTO SD AND POTENTIALLY EXTREME NRN NEB.
...SERN STATES...
PULSE-TYPE STORMS WILL CONTINUE TO DEVELOP THIS AFTERNOON ALONG A
COUPLE OF WEAK SURFACE BOUNDARIES EXTENDING FROM SRN NC/SC WWD
THROUGH THE GULF COAST STATES TO THE LOWER MS VALLEY. AIR MASS
ACROSS THIS REGION HAS BECOME VERY UNSTABLE /MLCAPES 2500-3500
J/KG/...THOUGH WEAK DEEP LAYER SHEAR WILL CONTINUE TO LIMIT THE
SEVERE POTENTIAL. AN MCV MOVING SWWD THROUGH WRN/CENTRAL AR WILL
AID IN CONVECTIVE DEVELOPMENT ALONG THE SURFACE BOUNDARY EXTENDING
WWD THROUGH THIS AREA. THOUGH AGAIN...WEAK DEEP LAYER SHEAR WILL
LIMIT THE SEVERE POTENTIAL TO LOW PROBABILITIES.
...SWRN AZ/SERN CA...
VIS IMAGERY SHOWS STRONG SURFACE HEATING WILL CONTINUE ACROSS THIS
AREA THROUGH THE AFTERNOON AIDING IN THE POTENTIAL FOR THUNDERSTORM
DEVELOPMENT AS THE REMNANTS OF CLAUDETTE MOVE WWD INTO SRN AZ.
DEEP ELY FLOW OVER SWRN AZ COMBINED WITH STEEP LOW-MID LEVEL LAPSE
RATES WILL SUPPORT THE POTENTIAL FOR LOCAL STRONG/DAMAGING WIND
GUSTS ACROSS SWRN AZ INTO SERN CA THIS AFTERNOON/EVENING.
..PETERS.. 07/17/03
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED FOR 0100Z
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