SPC AC 231242
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0742 AM CDT MON MAY 23 2005
VALID 231300Z - 241200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 20 ENE
JAX 10 ESE TLH 20 NNW GPT 40 E SHV 30 NNE DUA 55 WNW CSM 25 WSW AMA
10 WSW CVS 45 ENE LVS 15 S PUB 30 ESE CYS 10 NE CDR 20 WSW PIR HON
YKN 30 N GRI 50 S EAR 10 NW HUT 15 NNW JLN 25 NNE LIT 20 SSE UOX 20
S 0A8 40 ENE ABY 25 W SAV 40 ESE AGS 30 E CAE 35 W OAJ 15 W RWI 25
NE DAN 10 SW CHO 25 WSW DCA 15 ENE WAL.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 65 SE ELP 45 SE ALM
30 WNW ROW 40 ENE 4CR 20 WSW LVS 45 NE 4SL 20 W ASE 50 WSW CAG VEL
40 NE U24 20 SSE DPG 20 NW DPG 50 NE ENV 35 S BYI 15 W PIH 45 ESE
WEY 50 SSE BIL 40 ESE MLS 30 ESE SDY 60 NNE ISN ...CONT... 55 W RRT
40 W AXN 15 NNW RWF 20 NE SPW 60 NE OMA 40 SE OMA 15 WNW MKC 55 S
SZL 35 ENE JBR 40 WNW AND 45 E CLT 20 SE GSO 35 NW GSO 35 S JKL 20
SSW LUK 40 E SBN 15 NE MBL 10 E TVC 30 SSW OSC ...CONT... 60 E MTC
15 SE IPT 25 SSE NEL ...CONT... 25 SSE DAB 55 N PIE ...CONT... 45 SE
HUM 35 E LCH 50 SW TYR 30 WNW MWL 35 ESE BGS 20 NE FST 70 S MRF.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 W ONM 20 NNW TCS
35 WSW TCS 45 ENE SAD 25 N SAD 50 SSW SOW 65 ENE PHX 65 SSW INW 25
NE PRC 30 SE GCN 30 N INW 45 WSW GUP 40 S GUP 30 W ONM.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 35 NW CTB 30 E FCA 30
S FCA 25 NW 3TH 10 ENE GEG 30 WNW GEG 40 N EPH 30 W EAT 45 SE SEA 20
NE OLM 15 N BLI.

...THERE IS A SLGT RISK OF SVR TSTMS OVER A LARGE PART OF THE CNTRL
AND SRN PLNS...

...SYNOPSIS...
BROAD RIDGE WILL REMAIN ANCHORED OVER NRN MEXICO AND THE SWRN U.S.
THIS PERIOD AS BLOCK CONTINUES TO HOLD FIRM OVER NRN QUEBEC.
HEIGHTS WILL REBOUND SLIGHTLY OVER THE UPR MS VLY AS SWRN RIDGE
NOSES NEWD IN WAKE OF STRONG DISTURBANCE CONTINUING TO DROP SE FROM
THE UPR GRT LKS. ELSEWHERE...SATELLITE LOOPS SUGGEST PRESENCE OF
SEVERAL WEAKER FEATURES MOVING ALONG OUTER FRINGE OF SWRN
RIDGE...NONE OF WHICH APPEAR TO BE WELL DEPICTED IN THE MODELS. ONE
OF THESE IMPULSES IS MORE OR LESS COLLOCATED WITH AR/OK MCC...AND
ANOTHER IS ATTM OVER SW NEB.
FEATURES WILL REMAIN FAIRLY WEAK AT THE SURFACE. DIFFUSE FRONT...
AUGMENTED BY CONVECTIVE OUTFLOW..WILL SETTLE SLOWLY S ACROSS THE RED
RVR/LWR MS VLYS. FARTHER NE...A COMPLEX OF SOMEWHAT STRONGER
FRONTS/TROUGHS WILL ACCOMPANY SYSTEM DROPPING SE ACROSS THE OH
VLY/APLCNS. A BETTER DEFINED COLD FRONT WILL ALSO MOVE SE INTO THE
NRN PLNS...SUPPORTED BY SHORTWAVE IMPULSE NOW IN SRN SASKATCHEWAN.

...SRN PLNS/SRN OZARKS TO LWR MS VLY/CNTRL GULF CST STATES...
AR/OK MCC HAS DEVELOPED A FAIRLY SUBSTANTIAL COLD POOL. THE SYSTEM
IS LOCATED WITHIN A ZONE OF MODERATE /30 KT/ WNWLY FLOW ON EDGE OF
SWRN RIDGE. SURFACE DATA INDICATE THAT BOUNDARY LAYER MOISTURE AXIS
IS ORIENTED ROUGHLY PARALLEL TO THIS DIRECTION AND EXTENDS SE TO THE
CNTRL/ERN GULF CST.
WITH THE MID/UPR LEVEL FLOW EXPECTED TO SLIGHTLY VEER AND STRENGTHEN
OVER THE LWR MS VLY REGION TODAY...AND GIVEN THE ABOVE COLD POOL/
LOW LEVEL MOISTURE AXIS SETUP...EXPECT THAT AR/OK CONVECTIVE SYSTEM
WILL CONTINUE GENERALLY SEWD TODAY. AIR MASS AHEAD OF SYSTEM SHOULD
DESTABILIZE AS A RESULT OF BOTH SURFACE HEATING AND LOW LEVEL WLY
FLOW ADVECTING WARMTH/MOISTURE INTO REGION. THUS...THE EXISTING
SYSTEM... AND/OR STORMS FORMING ON ITS PERIPHERY...SHOULD INTENSIFY
LATER TODAY. GIVEN DEGREE OF SURFACE-BASED INSTABILITY /MLCAPE TO
2000 J PER KG/...FAIRLY STEEP LOW LEVEL LAPSE RATES AND 30-35 KT
DEEP W TO WNWLY SHEAR...THE STORMS COULD YIELD HIGH WIND AND HAIL AS
THEY ORGANIZE INTO CLUSTERS.
BACK N...ON THE UPSHEAR SIDE OF AR/OK MCC...MODERATE LLJ WILL
CONTINUE TO IMPINGE UPON WRN SIDE OF SYSTEM COLD POOL. GIVEN
QUALITY OF UPSTREAM MOISTURE INFLOW /DEWPOINTS IN THE MID TO UPPER
60S/ AND STEEP MID LEVEL LAPSE RATES...THIS COULD LEAD TO THE
PERIODIC DEVELOPMENT OF A FEW ELEVATED STORMS WITH LARGE HAIL OVER
MUCH OF OK AND PERHAPS SRN KS.

...SRN VA TO S ATLANTIC CST...
A SURFACE LOW SHOULD STRENGTHEN ALONG EXISTING FRONTAL ZONE SRN VA
LATER TODAY AS LEADING PORTION OF UPR GRT LKS DISTURBANCE DROPS
RAPIDLY SEWD. AS THE LOW DEVELOPS...ASSOCIATED LEE TROUGH SHOULD
BECOME BETTER DEFINED SWD INTO ERN SC AND SRN GA.
WHILE LOW LEVEL MOISTURE ACROSS THE REGION WILL BE RELATIVELY
LIMITED FOR LATE MAY...AVERAGE DEWPOINTS IN THE LOW 60S SHOULD
SUPPORT AFTERNOON MLCAPES OF 1000-1500 J/KG GIVEN PRESENCE OF FAIRLY
STEEP MID LEVEL LAPSE RATES AND LIKELIHOOD FOR GOOD SURFACE HEATING.
CONVERGENCE ALONG LEE TROUGH...AND POSSIBLY ALONG COLD FRONT FARTHER
N AND W...MAY BE SUFFICIENT TO INITIATE SCATTERED DIURNAL STORMS
FROM SRN VA SWD INTO ERN PARTS OF THE CAROLINAS. DEEP... LARGELY
UNIDIRECTIONAL 40-50 KT WNWLY SHEAR...COUPLED WITH 20 DEGREE
TEMPERATURE/DEWPOINT SPREADS...COULD PROMOTE UPSCALE DEVELOPMENT
INTO BANDS WITH HIGH WIND AND MARGINALLY SEVERE HAIL.

...CNTRL HI PLNS INTO CNTRL/NRN PLNS...
SETUP WILL BECOME INCREASINGLY FAVORABLE FOR SUPERCELLS LATE TODAY
INTO TONIGHT OVER THE CNTRL HI PLNS AS ESELY BOUNDARY LAYER MOISTURE
TRANSPORT CONTINUES BENEATH 30-35 KT WLY FLOW CRESTING SWRN RIDGE.
EXISTING LEE TROUGH EXTENDING FROM FAR ERN CO NNE INTO CNTRL SD WILL
BE INTENSIFIED BY DIURNAL INFLUENCES. THIS BOUNDARY WILL BE
AUGMENTED IN TIME BY COLD FRONT NOSING SWD IN WAKE OF SASKATCHEWAN
IMPULSE. COMBINATION OF UPSLOPE FLOW AND CONVERGENCE ALONG TROUGH
SHOULD INITIATE STORMS LATE THIS AFTERNOON FROM FAR ERN CO/NE NM NWD
INTO CNTRL PARTS OF NEB/SD. COMBINATION OF 40-50 KT DEEP WNWLY
SHEAR AND MLCAPE BETWEEN 2500 AND 3500 J/KG COULD YIELD A FEW
SUSTAINED SUPERCELLS WITH VERY LARGE HAIL/HIGH WIND AND PERHAPS A
TORNADO OR TWO.
WHILE THE NM/SRN CO STORMS SHOULD DIMINISH WITH NIGHTFALL...THOSE
FARTHER N WILL LIKELY BE JOINED BY ADDITIONAL ACTIVITY FORMING ALONG
AFOREMENTIONED COLD FRONT. AS LLJ STRENGTHENS...THIS ACTIVITY MAY
EVOLVE INTO ONE OR TWO LARGE NOCTURNAL MCSS THAT EXTEND A THREAT FOR
HAIL/HIGH WIND INTO ERN PARTS OF NEB/SD.

...UPR OH VLY/CNTRL APLCNS...
SURFACE HEATING DOWNSTREAM FROM POTENT UPR GRT LKS SHORTWAVE
TROUGH...COUPLED WITH DEEP/COOL CYCLONIC FLOW...MAY SUPPORT
DEVELOPMENT OF A FEW BANDS OF STRONG DIURNAL STORMS OVER PARTS OF
OH/WV AND SW PA. LOW FREEZING LEVELS AND MODERATE FORCING FOR
ASCENT MAY YIELD A FEW STORMS WITH MARGINALLY SEVERE HAIL AND
POSSIBLY STRONG WINDS.
..CORFIDI/JEWELL.. 05/23/2005

...NOTICE...
THE STATION RELATIVE POINTS IN THIS PRODUCT ARE NOW AVAILABLE
SEPARATELY UNDER THE WMO HEADINGS WUUS01 PTSDY1...
WUUS02 PTSDY2...WUUS03 PTSDY3. THE INCLUSION OF POINTS
IN THIS DISCUSSION WILL BE DISCONTINUED AFTER THE 2005
CONVECTIVE SEASON. A PUBLIC NOTIFICATION STATEMENT (PNS)
WILL PROVIDE DETAILS ON THE TRANSITION.