SPC 0100Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0802 PM CDT WED MAY 30 2012 VALID 310100Z - 311200Z ...THERE IS A MDT RISK OF SVR TSTMS PORTIONS NRN/ERN/CENTRAL OK...SRN KS...EXTREME WRN AR...EXTREME SWRN MO... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING MDT RISK FROM SRN MO TO CENTRAL TX...ERN TX PANHANDLE AND SWRN KS.... ...SYNOPSIS... UPPER-AIR PATTERN WILL REMAIN CHARACTERIZED BY TROUGHING FROM WRN QUE SWWD ACROSS CENTRAL PLAINS TO NWRN MEX. MOST SUBSTANTIAL/INFLUENTIAL SHORTWAVE PERTURBATION FOR REMAINDER PERIOD IS EVIDENT IN MOISTURE CHANNEL IMAGERY AND VWP/PROFILER DATA OVER ERN PORTIONS DAKOTAS...EXTENDING SSWWD ACROSS WRN KS TO TX/NM BORDER REGION. THIS TROUGH SHOULD MOVE SEWD TO UPPER MS VALLEY...NERN KS...AND NWRN/W-CENTRAL TX BY END OF PERIOD. AT SFC...COMPLEX 123Z ANALYSIS IS BEST SUMMARIZED BY SYNOPTIC WARM FRONT OVER CENTRAL/SRN MO EXTENDING WNWWD OVER NERN KS INTO ONGOING CONVECTIVE COMPLEX...AND DRIFTING NWD. COLD FRONT OVER NWRN KS AND ERN CO WILL CONTINUE MOVING SEWD TO SWRN MO...SERN OK...AND NW TX BY END OF PERIOD...PRECEDED BY EXTENSIVE COLD-POOL RELATED CONVECTIVE OUTFLOW. EARLIEST OUTFLOW BOUNDARY FROM PRIOR OVERNIGHT/MORNING CONVECTION HAS BECOME DIFFUSE...BUT STILL IS EVIDENT FROM NW TX SEWD NEAR MWL...ACT...LFK...BECOMING SHARPER/FRESHER WITH EWD EXTENT TO LEADING EDGE OF MS MCS. DRYLINE NOW RETREATING WWD ACROSS TX PANHANDLE AND SOUTH-PLAINS REGION WILL BE OVERTAKEN BY COLD FRONT OVERNIGHT. THIS OUTLOOK WILL BE SEGMENTED BY CONVECTIVE REGIME MORE THAN GEOGRAPHY...SINCE THERE IS SOME SPATIAL OVERLAP. ...CENTRAL PLAINS TO OK/AR/MO MCS WIND RISK... EXTENSIVE BAND OF SCATTERED-NUMEROUS TSTMS HAS FORMED OVER KS FROM NEAR MHK TO HUT TO BETWEEN GLD-GCK...AND SHOULD CONTINUE TO BECOME BETTER ORGANIZED AND MOVE SEWD. SVR WIND/DERECHO IS MAIN THREAT...WITH LARGE HAIL MOST PROBABLE FROM ANY EMBEDDED SUPERCELLS...AND CONDITIONAL/ISOLATED THREAT FOR TORNADOES MAINLY WITH EMBEDDED MESOCIRCULATIONS. DISCRETE SUPERCELLS AHEAD OF THIS ACTIVITY WILL POSE SVR HAIL/GUST THREAT. REF SPC WWS 323/325/326 AND RELATED MESOSCALE DISCUSSIONS FOR NEAR-TERM DETAILS. THIS COMPLEX MAY CONTINUE TO GROW LATERALLY -- I.E. BOTH ON ERN AND WRN SIDES -- AS UNSTABLE AIR MASS OVER THOSE PORTIONS OF KS IS USED...AND DEVELOP PROGRESSIVELY DEEPER/STRONGER AGGREGATE COLD POOL. THIS WILL DRIVE INCREASING THREAT FOR DAMAGING WIND AND POSSIBLE DERECHO LATER THIS EVENING AND OVERNIGHT. PATH OF GREATEST MAGNITUDE OF THIS EVENT STILL IS SOMEWHAT UNCERTAIN...AS MCS IS IN ITS EARLY STAGES AND RELATIVELY SMALL STORM-SCALE EFFECTS ARE DOMINATING PROCESSES RIGHT NOW IN ITS TWO PRIMARY NODES OF ORGANIZATION OVER CENTRAL/WRN KS. CONSENSUS OF PROGS OF FORWARD-PROPAGATIONAL MCS MOTION VECTORS SUGGEST MOST PROBABLE SWATH OVER S-CENTRAL/SERN KS...PORTIONS NRN/ERN OK...AND PERHAPS EXTENDING/EXPANDING INTO WRN OZARKS REGION AND PORTIONS CENTRAL/S-CENTRAL OK. AIR MASS AHEAD OF THIS ACTIVITY AND ESPECIALLY OVER CENTRAL/WRN OK...HAS BEEN DRIED BY CONVECTIVE PROCESSES FROM PREVIOUS DAY...WHICH REDUCES SFC THETAE...BUT ALSO...SUPPLIES SUBCLOUD DRYING TO AID DOWNDRAFT ACCELERATION. MOISTURE FOR THIS ACTIVITY WILL BE SUPPLIED LARGELY ABOVE SFC...IN FIELD OF 25-35 KT SLY TO SWLY WINDS IN 800-900 MB LAYER. ...NW/W-CENTRAL TX SUPERCELLS... TORNADO THREAT FCST TO CONTINUE FOR ANOTHER 2-3 HOURS WITH SUPERCELLS E SJT AND SW-SE CDS...EACH OF WHICH ALSO MAY FOSTER MESO-BETA-SCALE COLD POOLS WITH CORRESPONDINGLY ENHANCED WIND-DAMAGE THREAT. LARGE/DAMAGING HAIL ALSO REMAINS LIKELY AS LONG AS ACTIVITY MAINTAINS DISTINCTIVE SUPERCELLULAR CHARACTER. REF WWS 322...324...AND ACCOMPANYING MESOSCALE DISCUSSIONS FOR NEAR-TERM DETAILS. CONVECTION WILL BE AIDED...AND NOCTURNAL/DIABATIC INCREASE IN CINH SLOWED BY...TRIANGULAR CORRIDOR OF RELATIVELY RICH LOW-LEVEL MOISTURE EVIDENT AHEAD OF THIS ACTIVITY. SFC DEW POINTS MID-UPPER 60S F EXIST EITHER SIDE OF MOIST AXIS FROM NW TX SUPERCELL SSEWD OVER ERN EDWARDS PLATEAU AND WRN HILL COUNTRY...E OF DRYLINE AND SW OF OLDEST OUTFLOW BOUNDARY...AND BENEATH FAVORABLY STG DEEP SHEAR. ..SRN PORTIONS MS/AL...SERN LA... STG-SVR TSTMS REMAIN POSSIBLE OVER THIS REGION...AMIDST LINGERING SFC-BASED BUOYANCY PER MODIFIED LIX/BMX RAOBS...WITH STEEP LOW-MIDDLE LEVEL LAPSE RATES AND WELL-MIXED SUBCLOUD LAYER SUPPORTING GUST POTENTIAL. HOWEVER...OVERALL ORGANIZATION OF CONVECTION HAS DIMINISHED MARKEDLY WITH LOSS OF DIABATIC SFC HEATING. DAMAGING-WIND POTENTIAL THEREFORE HAS BECOME ISOLATED...AND SHOULD GENERALLY WEAKEN THROUGH REMAINDER EVENING DUE TO COMBINED STABILIZING EFFECTS OF OUTFLOW AND DIABATIC SFC COOLING. ..EDWARDS.. 05/31/2012
via SPC Forecast Products http://www.spc.noaa.gov/products/outlook/day1otlk_0100.html
Be First to Comment