SPC AC 111300
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0800 AM CDT FRI JUN 11 2010
VALID 111300Z - 121200Z
...THERE IS A SLGT RISK OF SVR TSTMS THROUGH TONIGHT FROM SE CO TO
WI AND WRN LOWER MI...
...WI/NRN IL/ERN IA THROUGH LATE AFTERNOON...
THE REMNANTS OF A LARGE OVERNIGHT MCS...WITH ASSOCIATED MCV/S OVER
SW MN AND W CENTRAL IA...WILL CONTINUE ENEWD TODAY TO WI...WITH
GRADUAL WEAKENING OF THE STORM COMPLEX EXPECTED BY MIDDAY. THERE
WILL...HOWEVER...BE SOME POTENTIAL FOR STRONG/SEVERE STORMS TO
DEVELOP THIS AFTERNOON ALONG THE REMNANT OUTFLOW AND/OR WARM FRONT
ACROSS SRN/CENTRAL WI...PRIOR TO THE PRIMARY MCV MOVING NE OF THE
UNSTABLE WARM SECTOR. DEEP-LAYER VERTICAL SHEAR WILL BE AT LEAST
MARGINALLY FAVORABLE FOR ORGANIZED STORMS /INCLUDING
SUPERCELLS/...ESPECIALLY IN PROXIMITY TO THE WARM FRONT WHERE
LOW-LEVEL SHEAR WILL BE STRONGER. A FEW DAMAGING GUSTS...AND
PERHAPS A TORNADO...WILL BE POSSIBLE ACROSS CENTRAL/SRN WI THIS
AFTERNOON. ISOLATED LARGE HAIL WILL ALSO BE POSSIBLE.
...NRN KS AREA THIS AFTERNOON INTO EARLY TONIGHT...
THE OUTFLOW BOUNDARY TRAILING THE MCS HAS MOVED SEWD INTO NW MO AND
SWD INTO NRN KS. THIS BOUNDARY MAY PERSIST INTO THE AFTERNOON AND
ACT AS THE EFFECTIVE FRONT...PROVIDING A FOCUS FOR NEW THUNDERSTORM
DEVELOPMENT. A FEED OF LOW-MID 70S BOUNDARY LAYER DEWPOINTS FROM OK
INTO ERN KS...BENEATH THE NE EXTENSION OF THE EML PLUME...WILL
MAINTAIN STRONG INSTABILITY IN THE WARM SECTOR. THUNDERSTORM
DEVELOPMENT WILL LIKELY BE DELAYED UNTIL LATE AFTERNOON ALONG THE
REMNANT BOUNDARY BY THE SUBSTANTIAL CAP NOTED IN THE 12Z DDC/TOP
SOUNDINGS. RATHER MODEST DEEP-LAYER VERTICAL SHEAR IS SUGGESTIVE OF
MULTICELL CLUSTERS AND ONLY BRIEF SUPERCELL STRUCTURES ACROSS NRN
KS...WHILE THE CONVECTION SHOULD EXPAND ON CONVECTIVE OUTFLOWS
THROUGH THE EARLY OVERNIGHT HOURS AS THE SLY LLJ STRENGTHENS.
DAMAGING WINDS AND LARGE HAIL WILL BE THE MAIN THREATS.
...E/SE CO THIS AFTERNOON INTO W/NW KS TONIGHT...
ERN CO WILL BE ALONG THE ERN EXTENT OF THE BELT OF 35-50 KT SSWLY
MIDLEVEL FLOW DOWNSTREAM FROM THE DEVELOPING SRN GREAT BASIN CLOSED
LOW. IN THE LOW LEVELS...A DEVELOPING UPSLOPE FLOW REGIME WITH
BOUNDARY LAYER DEWPOINTS IN THE 50S WILL COMBINE WITH DAYTIME
HEATING IN CLOUD BREAKS TO SUPPORT MODERATE INSTABILITY IMMEDIATELY
E OF FRONT RANGE FROM ROUGHLY COLORADO SPRINGS SWD INTO S/SE CO.
THE NET RESULT WILL BE SUFFICIENT DEEP-LAYER AND LOW-LEVEL SHEAR FOR
SUPERCELLS E OF THE MOUNTAINS THIS AFTERNOON/EVENING. THE INITIAL
STORMS WILL BE CAPABLE OF PRODUCING LARGE HAIL AND A TORNADO OR TWO.
STORMS SHOULD THEN GROW UPSCALE INTO ONE OR MORE CLUSTERS BY EARLY
TONIGHT WITH AN ATTENDANT RISK FOR DAMAGING WINDS.
..THOMPSON/SMITH.. 06/11/2010
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
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