SPC 0100Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0800 PM CDT FRI APR 27 2012 VALID 280100Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS LOWER MO VALLEY TO OZARKS AND SERN KS... ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS SC AND NERN GA... ...SYNOPSIS... PROGRESSIVE UPPER-AIR PATTERN FEATURES TWO RATHER HIGHLY AMPLIFIED TROUGHS...FIRST OVER NEW ENGLAND AND NEXT OVER MT/WY. 500-MB LOW IS EMBEDDED IN WRN TROUGH OVER CENTRAL MT...AND SHOULD MOVE SEWD TO BLACK HILLS REGION BY END OF PERIOD. AS THAT OCCURS...COMPACT SHORTWAVE TROUGH -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY AND VWP/PROFILER DATA OVER SRN NEB AND NRN KS -- SHOULD TRANSLATE NEWD AND WEAKEN CONSIDERABLY. BY 12Z...REMAINS OF THIS FEATURE WILL BE MANIFEST AS ZONAL OR WNW-ESE ALIGNED BAND OF MID-UPPER VORTICITY FROM SERN SD ACROSS MN/IA BORDER REGION. 23Z SFC MAP SHOWED SFC LOW BETWEEN SLN-CNK...WHICH IS FCST TO MOVE NEWD TO SRN IA AND FILL THROUGH TONIGHT. WARM FRONT WAS ANALYZED FROM LOW SEWD ACROSS CNU/JLN AREAS THEN OVER N-CENTRAL AR. THIS BOUNDARY SHOULD MOVE NEWD ACROSS WRN/SRN MO OVERNIGHT...REACHING FROM LOW SEWD ACROSS ERN MO AND SRN IL BY DAYBREAK. DRYLINE WAS ANALYZED FROM LOW SSEWD OVER OSAGE COUNTY OK THEN SWWD NEAR SNL AND DUC TO NEAR BWD. DRYLINE SHOULD RETREAT NWWD ACROSS OK AND STALL ACROSS SERN KS BEFORE BEING OVERTAKEN BY COLD FRONT. COLD FRONT SWWD ACROSS NERN OK AND EXTREME NRN PANHANDLE OF TX...AND SHOULD REACH CENTRAL MO...CENTRAL OK AND NW TX BY 12Z. NRN AR FRONTAL ZONE EXTENDS ESEWD ACROSS NRN PORTIONS AL/GA/SC. SC SEGMENT OF FRONT EFFECTIVELY WILL BE SHUNTED SWD TEMPORARILY BY CONVECTIVE OUTFLOW...OTHERWISE SERN CONUS PORTION OF THIS BOUNDARY WILL MOVE NWD OVER TN VALLEY REGION. ...LOWER MO VALLEY TO OZARKS AND SERN KS... BAND OF STG-SVR TSTMS CONTINUES TO MOVE NEWD ACROSS PORTIONS NERN KS AND SERN NEB...WITH SVR THREAT TRANSITIONING TO HAIL AND ISOLATED GUSTS. TORNADO THREAT SHOULD DIMINISH WITH EXISTING TSTMS AS THEY CONTINUE TO OUTPACE PROGRESS OF SFC WARM FRONT...AND IN DOING SO...MOVE ATOP PROGRESSIVELY MORE STABLE BOUNDARY LAYER. HOWEVER...POTENTIAL FOR SVR HAIL WILL REMAIN. THREAT REMAINS FOR DEVELOPMENT OVER SERN KS/SWRN MO IN NARROW WARM-SECTOR CORRIDOR BETWEEN DRYLINE AND COLD FRONT...BUT WILL DIMINISH LATER THIS EVENING AS STRONGEST DEEP-LAYER ASCENT PASSES FARTHER N OF AREA. REF REMAINDER WWS 194...196...AND RELATED MESOSCALE DISCUSSIONS FOR NEAR-TERM FCST DETAILS. ...SERN CONUS... SCATTERED MULTICELLULAR TSTMS IN CLUSTERS WILL CONTINUE TO MOVE ESEWD ACROSS NERN GA AND PARTS OF SC THROUGH EVENING. POTENTIAL LINGERS FOR OCNL DAMAGING GUSTS AND MRGL SVR HAIL...BUT WILL DIMINISH CONSIDERABLY AFTER ABOUT 03Z DUE TO COMBINATION OF DIABATIC SFC COOLING AND STABILIZATION BY OUTFLOWS. REF SPC WW 195 AND RELATED MESOSCALE DISCUSSIONS. ..EDWARDS.. 04/28/2012
via SPC Forecast Products http://www.spc.noaa.gov/products/outlook/day1otlk_0100.html
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