SPC 1200Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1243 AM CDT SAT MAR 30 2013 VALID 301200Z - 311200Z ...THERE IS A SLGT RISK OF SVR TSTMS FOR PARTS OF THE CNTRL/SRN PLAINS... ...SYNOPSIS... AS AN UPPER-LEVEL LOW PERSISTS OFF THE WEST COAST...A GENERAL W/NWLY MID-LEVEL FLOW REGIME WILL CONTINUE E OF THE ROCKIES. A SERIES OF LOW-AMPLITUDE SHORTWAVE IMPULSES WILL EJECT E/SEWD ACROSS THE N-CNTRL CONUS. A WEAK MID-LEVEL IMPULSE APPROACHING THE SRN CA/NRN BAJA CA COAST SHOULD GRADUALLY PROGRESS EWD...UNDERCUTTING THE SOUTHWEST RIDGE. AT THE SURFACE...A WEAK COLD FRONT SHOULD PUSH ACROSS THE CNTRL PLAINS AND REACH THE LOWER MO VALLEY DURING THE AFTERNOON. TRAILING PORTION OF THIS BOUNDARY WILL LIKELY ACCELERATE SWD ACROSS THE SRN HIGH PLAINS SAT NIGHT. QUASI-STATIONARY FRONT IN THE SRN PLAINS WILL ATTEMPT TO ADVANCE NEWD ACROSS THE OZARK PLATEAU. ...LOWER MO VALLEY TO THE SRN HIGH PLAINS... LOW CONFIDENCE EXISTS BUT A RISK FOR ISOLATED LARGE HAIL COULD DEVELOP NEAR THE LOWER MO VALLEY/OZARK PLATEAU THIS AFTERNOON/EARLY EVENING AND W/SWWD TOWARDS THE SRN HIGH PLAINS IN THE EVENING/OVERNIGHT. A COUPLE OF MCS/S WILL LIKELY BE ONGOING AT 12Z/SAT FROM PARTS OF TEXARKANA/OZARK PLATEAU NWD TOWARDS THE LOWER MO VALLEY. ALTHOUGH SOME STRONGER CORES ARE POSSIBLE WITHIN THESE COMPLEXES...SUBSTANTIALLY WEAKER DOWNSTREAM INSTABILITY SHOULD MITIGATE ROBUST DIURNAL INTENSIFICATION. HOWEVER...PERSISTENT LOW-LEVEL WAA MAY YIELD MARGINAL HAIL/WIND POTENTIAL WITH ANY REDEVELOPMENT ALONG THE WRN FLANK. OUTFLOW FROM THIS ACTIVITY SHOULD SERVE TO REINFORCE THE QUASI-STATIONARY/WARM FRONT WHICH WILL PROBABLY YIELD A PRONOUNCED ZONE OF DIFFERENTIAL HEATING BY AFTERNOON. CONVERGENCE ALONG THE NE/SW-ORIENTED COLD FRONT APPROACHING FROM THE CNTRL PLAINS SHOULD GENERALLY REMAIN WEAK. BUT SOME ENHANCEMENT TO LARGE-SCALE ASCENT ASSOCIATED WITH THE N-CNTRL CONUS SHORTWAVE IMPULSES MAY SUPPORT ISOLATED TSTMS FORMING LATE DAY IN SERN KS/NERN OK. MODERATE DEEP-LAYER SPEED SHEAR AND STEEP MID-LEVEL LAPSE RATES WOULD FAVOR LARGE HAIL AS THE PRIMARY THREAT. LOW-LEVEL FLOW WILL LARGELY REMAIN WEAK AND DIVERGENT WITH SRN EXTENT TOWARDS S-CNTRL OK...BREEDING SUBSTANTIAL UNCERTAINTY OVER THE DEVELOPMENT OF ANY TSTMS ALONG THE RED RIVER DESPITE PRESENCE OF MLCAPE AROUND 2000 J/KG WITH MINIMAL MLCIN BY LATE DAY. STILL...A TSTM OR TWO COULD FORM ALONG ANY REMNANT OUTFLOW BOUNDARY AND WOULD POSE A RISK FOR LARGE HAIL. A MORE PROBABLE SCENARIO FOR TSTM DEVELOPMENT SHOULD BE ACROSS PARTS OF THE SRN HIGH PLAINS /CENTERED OVER THE TX PANHANDLE/ TONIGHT. CONVERGENCE ALONG THE FRONT/DRYLINE WILL STRENGTHEN...PERHAPS IN RESPONSE TO IMPULSES APPROACHING FROM AZ/NM AND THE CNTRL HIGH PLAINS. ON THE WRN FRINGE OF THE BUOYANCY AXIS...A FEW TSTMS WITH SEVERE HAIL MAY DEVELOP BY LATE EVENING INTO THE OVERNIGHT. ..GRAMS/DEAN.. 03/30/2013
via SPC Forecast Products http://www.spc.noaa.gov/products/outlook/day1otlk_1200.html
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