000 ACUS01 KWNS 040535 SWODY1 SPC AC 040533 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 1233 AM CDT SAT JUL 04 2009 VALID 041200Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE LWR OH/MID-MS VLY WWD INTO THE SRN PLNS... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CNTRL/NRN HIGH PLAINS... CORRECTED FOR DAY OF WEEK ...SYNOPSIS... QSTNRY UPR LOW OVER ONT/QUE WILL PERSIST INTO SATURDAY AS AN ASSOCD UPR TROUGH WEAKENS ALONG THE ERN SEABOARD. IN ITS WAKE...WNWLY UPR FLOW REGIME WILL EXIST FROM THE NRN GRT BASIN TO THE MID-ATLC CST...ALONG THE PERIPHERY OF A SUBTROPICAL HIGH. AT THE SFC...A LOW WILL MOVE FROM ERN KS INTO THE LWR OH VLY BY SATURDAY NIGHT. A TRAILING CDFNT WILL SETTLE SWD INTO THE MID-SOUTH AND PARTS OF THE SRN PLNS WHILE A WRMFNT DEVELOPS NEWD THROUGH THE UPR OH VLY. ...MO/AR OZARKS EWD INTO THE LWR OH VLY... SVRL TSTM CLUSTERS...MOSTLY ELEVATED AND SUB-SVR...WILL BE ONGOING AT 12Z SATURDAY FROM PARTS OF ERN KS INTO CNTRL IL. STORMS WILL BE ENHANCED BY CONSIDERABLE LOW/MID-LVL THETA-E ADVECTION ALONG/N OF THE SFC LOW/WRMFNT. ACTIVITY WILL CONTINUE EWD INTO THE MIDWEST THROUGH THE DAY. PRIMARY SVR THREATS SHOULD EVOLVE SATURDAY AFTN FROM THE LWR OH VLY WWD INTO THE MO/AR OZARKS. MODELS ARE IN EXCELLENT AGREEMENT TRACKING THE CNTRL ROCKIES MID-LVL SHORTWAVE TROUGH TO THE MID-MS VLY BY LATE AFTN. INFLUENCE OF THIS WAVE/ASCENT AND STRONG HEATING ALONG/S OF OUTFLOW BOUNDARIES/CDFNT WILL CONTRIBUTE TO STRENGTHENING STORMS. DEEP LAYER SHEAR OF 45-50 KTS WILL AID IN STORM ORGANIZATION/SUPERCELLS WITH LARGE HAIL AND DMGG WIND GUSTS. ISOLD TORNADOES MAY ALSO OCCUR...PRIMARILY FROM SERN MO INTO SRN IL NEAR THE TRACK OF THE SFC LOW. ACTIVITY SHOULD EVOLVE INTO SMALL SCALE BOWS AND WEAKEN AS THEY TRACK INTO CNTRL KY/MIDDLE TN AFTER ABOUT 03Z SUNDAY. ...SRN PLNS... STRONG HEATING IS EXPECTED ALONG/S OF ADVANCING CDFNT AND OUTFLOW BOUNDARIES SATURDAY AFTN. SFC DEW POINTS UPR 60S/LWR 70S COMBINED WITH VERY HOT TEMPERATURES WILL PRODUCE MLCAPES 2000 J/KG FROM THE TX S PLNS EWD INTO OK. SUSTAINED LLVL CONVERGENCE INVOF THE BOUNDARIES WILL YIELD WDLY SCT ROBUST TSTM DEVELOPMENT...INITIALLY ALONG OUTFLOW BOUNDARIES IN CNTRL/ERN OK...THEN ALONG THE CDFNT FROM WRN OK/TX S PLNS LATER. THOUGH DEEP LAYER SHEAR WILL BE COMPARATIVELY LESS ACROSS THE REGION THAN AT POINTS FARTHER NE...INVERTED-V SUB-CLOUD THERMODYNAMIC PROFILES AND MID-LVL DRY AIR WILL AUGMENT DOWNDRAFTS RESULTING IN DMGG WIND GUSTS. THE STRONGEST OF STORMS MAY ALSO PRODUCE LARGE HAIL...THOUGH TROPOSPHERIC TEMPERATURES WILL BE RATHER WARM. SVR THREATS WILL CONTINUE SWD INVOF BOUNDARIES DURING THE EVENING. ...ERN CO/WY... AFTER EARLY DAY LOW CLOUDS...DIURNAL UPSLOPE WILL COMMENCE SATURDAY AFTN AMIDST INCREASING HEATING/MAINTENANCE OF LLVL MOISTURE. WEAK PV-ANAMOLY OVER NRN CA IS EXPECTED TO AID IN HIGHER TERRAIN STORMS BY LATE SATURDAY AFTN FROM ERN CO NWD INTO WY. REGION WILL REMAIN WITHIN A MODEST BELT OF WLYS WITH DEEP LAYER SHEAR SUFFICIENT FOR SUPERCELLS WITH LARGE HAIL. STORM MOTION IS EXPECTED TO BE SLOW SSEWD WITH THE ADJACENT HIGH PLNS SVR THREATS /SVR HAIL-WIND GUSTS/ INCREASING DURING THE EVENING. ..RACY.. 07/04/2009