SPC 0730Z Day 3 Outlook
DAY 3 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0135 AM CDT THU AUG 22 2013 VALID 241200Z - 251200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... AN UPPER-LEVEL RIDGE WILL GRADUALLY SHIFT EWD FROM THE NRN PLAINS INTO THE UPPER GREAT LAKES REGION DURING THE D3 PERIOD. BENEATH THIS FEATURE...A 30+ KT LOW-LEVEL SWLY JET WILL PERSIST DURING THE DAY INTO THE NIGHT FROM WRN KS INTO THE UPPER MS VALLEY. AT THE SURFACE...A LEE TROUGH WILL EXTEND SWD FROM THE NRN INTO THE CNTRL HIGH PLAINS. GUSTY SLY WINDS E OF THE TROUGH AND VIGOROUS BOUNDARY LAYER MIXING WILL PROMOTE HOT TEMPERATURES OVER MUCH OF THE GREAT PLAINS. ...NRN PLAINS INTO THE UPPER GREAT LAKES REGION... ELEVATED THUNDERSTORMS MAY BE ONGOING WITHIN THE EXIT REGION OF A SWLY LLJ DURING SATURDAY MORNING FROM ND INTO NRN MN. INITIATION OF ADDITIONAL ISOLATED STORMS WILL THEN BE POSSIBLE DURING THE AFTERNOON ALONG A SURFACE TROUGH EXTENDING SWD FROM ND INTO THE CNTRL HIGH PLAINS. DEWPOINTS IN THE MID 50S TO LOW 60S COMBINED WITH STRONG SURFACE HEATING AND STEEP MIDLEVEL LAPSE RATES WILL AID IN MLCAPE VALUES FROM 1500-2500 J/KG. VEERING WINDS WITH HEIGHT AND DEEP-LAYER SHEAR UPWARDS OF 35 KT COULD SUPPORT A FEW SUPERCELLS INITIALLY...WITH ACTIVITY POSSIBLY GROWING UPSCALE WITH TIME AS THE LLJ RESTRENGTHENS NEAR SUNSET. IT IS UNCERTAIN WHETHER A CONCENTRATED SEVERE THREAT WILL MATERIALIZE ATTM...BUT AN UPGRADE TO SLGT RISK IS NOT OUT OF THE QUESTION IN FUTURE OUTLOOKS. ..GARNER.. 08/22/2013
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