SPC Day 1 Thunderstorm Outlook Issued 16Z 20030526


ZCZC SPCSWODY1 ALL
ACUS01 KWNS 261602
SPC AC 261601

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

VALID 261630Z - 271200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM
45 ESE GDV 25 SSW REJ 25 NW SNY 25 E LIC 50 N CAO 30 NW CAO
20 ESE RTN 20 WSW RTN 35 ESE ALS 50 WSW COS 30 NNE 4FC 35 SSW DGW
60 N CPR 35 NNE WRL 50 S BIL 10 N BIL 65 NNE BIL 60 SSW GGW
25 SW OLF 15 WSW SDY 45 ESE GDV.

THERE IS ALSO A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM
30 S CHS 40 NNW CHS 20 NNE FLO 30 NE FAY 30 ENE RWI 15 NE ECG.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 NE SSI 20 S AYS
30 SSE TLH ...CONT... 15 NE GLS 50 N PSX 15 W NIR 45 WNW MFE
...CONT... 40 SE ELP 25 NNE ELP 60 NW TCS 40 NNE GUP 20 NE GJT
20 NW RWL LND 35 SE JAC 20 NW BOI 15 ESE BKE 35 SSW LWS 40 NE PUW
85 NW FCA ...CONT... 75 NE DVL 25 SW JMS 20 E PHP 25 SW LBL
20 SE PVW 60 NNW ABI 20 WSW FTW 40 SSW ELD 40 NE MEI 10 SW ATL
30 SW AVL 30 SE TRI 10 WSW PSK 20 NNW LYH 30 SSW WAL.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 45 SSW STL
50 ENE COU 40 ESE UIN 20 NNW DEC 15 SE DNV IND 35 NNW SDF
30 NE OWB 25 N PAH 25 W MDH 45 SSW STL.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 25 NNW PBG 10 E ALB
POU 20 WNW TTN 35 WNW CXY 30 NNE PSB 20 N BUF.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 SSE SRQ
25 NNW MLB.



SATELLITE AND UPPER AIR ANALYSIS INDICATES STRONG BLOCKING PATTERN
ACROSS THE U.S.  THIS IS DOMINATED BY MID/UPPER LEVEL LOW OVER THE
ERN GREAT LAKES WITH ITS ASSOCIATED CIRCULATION COVERING THE
CENTRAL AND ERN PARTS OF THE U.S.  ALSO...HI AMPLITUDE RIDGE
EXTENDS FROM CA NEWD INTO THE WRN DAKOTAS LEAVING MODERATE FLOW
OVER THE NWRN U.S.  SURFACE RIDGING OVER SWRN ONTARIO NOW EXTENDS
SWD ACROSS THE UPPER MS VALLEY INTO THE CENTRAL PLAINS.  THIS HAS
LEFT A QUASISTATIONARY BOUNDARY FROM ERN NC WSWWD ACROSS SRN MS
INTO THE S PLAINS OF TX AND ALONG THE FRONT RANGE OF THE SRN AND
CENTRAL ROCKIES INTO ERN MT.

...CENTRAL AND ERN MT INTO THE FRONT RANGE OF CO...

SURFACE/LOW LEVEL MOISTURE HAS BEEN PUSHED UP AGAINST THE ROCKIES
THIS MORNING AS THE SURFACE RIDGE HAS EXTENDED SWD INTO THE PLAINS.

WATER VAPOR SATELLITE IMAGERY SHOWS CYCLONIC CIRCULATION ASSOCIATED
WITH GREAT LAKES LOW COMBINED WITH MODERATE MID LEVEL FLOW OVER THE
NWRN U.S. HAS DELINEATED A DEFORMATION ZONE OVER ERN MT SWD THROUGH
ERN WY.  00Z VERSION OF NSSL MM5 SHOWED THIS AREA TO BE THE BEST
FOR DEVELOPMENT OF CONVECTION...AND THE MORNING 40KM ETA ALSO
INDICATED THIS AS A SECONDARY LOW DEVELOPS OVER S CENTRAL MT
UNDERNEATH UPPER LEVEL JET EXIT REGION.  REMAINING AIR MASS ACROSS
THIS AREA IS MOIST WITH SURFACE DEW POINTS IN THE LOW/MID 50S...AND
WITH DAYTIME HEATING IS POTENTIALLY UNSTABLE WITH SBCAPE FORECAST
TO BE AROUND 1500 J/KG.  EXPECT THUNDERSTORMS TO REDEVELOP THIS
AFTERNOON WITH DAYTIME HEATING AS LOW DEVELOPS ENHANCING UVVS. 
ISOLATED SEVERE THUNDERSTORMS COULD PRODUCE DAMAGING WINDS AND HAIL
INTO EARLY TONIGHT.  AREA EXTENDS SWD INTO PARTS OF CO WHERE THERE
IS STILL SOME UPSLOPE FLOW ENHANCING CONVERGENCE ACROSS THE FRONT
RANGE.

...ERN NC AND SC...

MODELS INDICATE THAT FRONTAL BOUNDARY ACROSS AREA HAS LIMITED THE
ERN AREAS TO ANY SEVERE WEATHER THREAT THIS AFTERNOON AND THIS
EVENING.  LOW LEVEL FLOW IS WLY ACROSS THE AREA AS WEAK MID/UPPER
LEVEL SHORTWAVE TROUGH/ASSOCIATED VORTICITY MAX MOVES EWD ACROSS
NRN AL/NRN GA...JUST AHEAD OF COMPARATIVELY STRONGER FEATURE MOVING
SWD/SEWD OVER THE LOWER MO VALLEY.  SCATTERED THUNDERSTORMS ARE
EXPECTED IN MOIST AIR MASS WITH DEW POINTS IN THE MID 60S AND WHERE
MODELS SHOW SBCAPE TO APPROACH 2000 J/KG LATER TODAY.  SOME WET
MICROBURST POTENTIAL EXISTS WITH THE STORMS AS WELL AS SOME HAIL. 
 
..MCCARTHY/BANACOS.. 05/26/03

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