SPC 2000Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0300 PM CDT SAT JUN 16 2012 VALID 162000Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM SOUTHEAST CO...ACROSS MUCH OF OK...THE MID/UPPER MS VALLEY...INTO LOWER MI...... ...IA/MO/IL/WI/MI... SCATTERED TSTMS CONTINUE TO INCREASE ACROSS SOUTHERN IA/NORTHERN MO INTO IL/INDIANA AT MID-AFTERNOON WITHIN AN UNSTABLE/WEAKLY CAPPED BOUNDARY LAYER AHEAD OF AN MCV NEAR NORTHWEST MO. ONLY OUTLOOK CHANGE WAS TO INTRODUCE A CORRIDOR OF SLIGHTLY HIGHER WIND PROBABILITIES PER SEVERE TSTM WATCHES 400/401. ...SOUTHEAST CO TO TX/OK PANHANDLES... LIMITED SPATIAL ADJUSTMENTS TO EXISTING SLIGHT RISK WERE MADE TO ACCOUNT FOR DEVELOPMENTAL TRENDS NEAR THE CO FRONT RANGE...BUT SCENARIO OTHERWISE REMAINS AS PREVIOUSLY FORECAST. ...OK... NO CHANGES...SEE PRIOR DISCUSSION BELOW. ...FAR EAST/NORTHEAST MN AND NORTHWEST WI... RELATIVELY LOW-TOPPED STORMS WILL CONTINUE TO DEVELOP/INCREASE IMMEDIATELY AHEAD OF A SHORTWAVE TROUGH ACROSS SOUTHERN MANITOBA/NORTHERN MN. A FEW STORMS MAY PRODUCE DAMAGING WINDS/SOME HAIL. ..GUYER.. 06/16/2012 .PREV DISCUSSION... /ISSUED 1129 AM CDT SAT JUN 16 2012/ ...IA/MO/IL/WI/MI... SATELLITE/RADAR IMAGERY SHOW A SERIES OF REMNANT MCVS OVER PARTS OF NEB/KS/OK. THESE FEATURES HAVE BEEN WEAKENING THROUGH THE MORNING...BUT ARE LIKELY TO PERSIST IN SUFFICIENT STRENGTH INTO THE AFTERNOON TO ENHANCE CONVECTIVE RE-DEVELOPMENT OVER PARTS OF IA/MO. THE AIR MASS OVER THIS REGION HAS BEEN RAPIDLY DESTABILIZING WITH DEWPOINTS IN THE MID 60S TO LOWER 70S AND MLCAPE VALUES OVER 2000 J/KG NOTED. EFFECTIVE DEEP-LAYER SHEAR IS NOT PARTICULARLY STRONG ACROSS THIS AREA...BUT THE HBR PROFILER NEAR ICT SHOWED A PRONOUNCED MID LEVEL REAR-INFLOW JET ASSOCIATED WITH THE MCV A FEW HOURS AGO. THIS MAY HELP TO ORGANIZE CONVECTION INTO A BOWING SEGMENT LATER TODAY. PRESENT INDICATIONS ARE THAT STORMS WILL FORM FIRST OVER NORTHERN MO/SOUTHERN IA AND TRACK EAST-NORTHEASTWARD THROUGH THE AFTERNOON AND EVENING INTO NORTHERN IL/SOUTHERN WI AND PERHAPS INTO LOWER MI TONIGHT. DAMAGING WINDS ARE LIKELY TO BE THE MAIN THREAT...AS WEAK MID LEVEL LAPSE RATES TEND TO WEAKEN UPDRAFTS AND LIMIT THE LARGE HAIL POTENTIAL. ...OK... THE REMNANT OUTFLOW BOUNDARY FROM OVERNIGHT CONVECTION NOW STRETCHES E-W ACROSS CENTRAL OK AND IS DISSIPATING. THIS REGION IS EXPECTED TO BECOME ONLY WEAKLY CAPPED BY MID/LATE AFTERNOON WITH SEVERAL MODEL SOLUTIONS INDICATING THUNDERSTORM DEVELOPMENT. VERTICAL SHEAR AND STEERING FLOW WILL BE WEAK...SUGGESTING SLOW MOVING MULTICELL STORMS. HOWEVER...HIGH CAPE VALUES AND PRESENCE OF BOUNDARY MAY BE SUFFICIENT FOR A FEW SEVERE STORMS CAPABLE OF DAMAGING WINDS AND HAIL. ...SOUTHEAST CO INTO TX/OK PANHANDLES... SOUTHEASTERLY LOW LEVEL WINDS HAVE DEVELOPED ON BACK SIDE OF OVERNIGHT MCS...HELPING TO TRANSPORT MOISTURE WESTWARD INTO SOUTHEAST CO. ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP IN THIS CORRIDOR LATER THIS AFTERNOON AND SPREAD SLOWLY SOUTHEASTWARD DURING THE EVENING. EASTERLY COMPONENT OF LOW LEVEL WINDS WILL COMBINE WITH WEAK WESTERLY FLOW ALOFT FOR SUFFICIENT EFFECTIVE SHEAR FOR OCCASIONAL SUPERCELL STRUCTURES. HAIL AND DAMAGING WINDS APPEAR POSSIBLE IN THE STRONGEST STORMS.
via SPC Forecast Products http://www.spc.noaa.gov/products/outlook/day1otlk_2000.html
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