SPC AC 150528
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1228 AM CDT SUN JUL 15 2007
VALID 161200Z - 171200Z
...THERE IS A SLGT RISK OF SVR TSTMS FROM IA TO NWRN OH...
...MID MS VALLEY TO LOWER GREAT LAKES...
ALTHOUGH MODELS AGREE IN OVERALL LARGE SCALE FEATURES OVER THE NEXT
FEW DAYS...DISCREPANCIES EXIST IN REGARDS TO INDIVIDUAL SHORTWAVE
TROUGHS AS THEY ROTATE INTO THE BASE OF THE GREAT LAKES TROUGH. OF
PARTICULAR CONCERN IS THE DIFFERENCE IN INTENSITY OF SHORTWAVE
DIGGING SEWD ACROSS MN/WI EARLY IN THE PERIOD. BOTH 00Z NAM AND GFS
SOLUTIONS DROP THIS FEATURE INTO LOWER MI...ALTHOUGH GFS IS WEAKER
AND FASTER WITH TROUGH AXIS EAST OF LAKE MI BY 18Z.
IN ALL LIKELIHOOD AN EXPANSIVE CLUSTER OF THUNDERSTORMS WILL BE
ONGOING AT THE START OF THE PERIOD AHEAD OF THE AFOREMENTIONED
SHORTWAVE. SEWD MOVEMENT/EXPANSION ACROSS WI INTO LOWER MI SEEMS
REASONABLE GIVEN THE LARGE SCALE PATTERN. THE MAIN QUESTION FOR
DAY2 WILL BE THE POTENTIAL FOR RENEWED CONVECTIVE DEVELOPMENT ALONG
OUTFLOW/COLD FRONT AS IT SAGS SWD INTO IA/NRN IL/NRN IND/NWRN OH
LATER IN THE AFTERNOON. DEEPENING WLY FLOW ACROSS THE CNTRL
PLAINS/MID MS VALLEY WILL ALLOW STEEPER LAPSE RATE PLUME TO SPREAD
ACROSS THIS REGION AHEAD OF WIND SHIFT. ALTHOUGH LARGE SCALE ASCENT
WILL WANE IN THE WAKE OF TROUGH AXIS...STRONG DIURNAL HEATING ACROSS
IA SHOULD REMOVE INHIBITION FOR PARCELS TO REACH THEIR LFC WITH ANY
EXCUSE FOR CONVERGENCE. LATEST THINKING IS SCATTERED THUNDERSTORMS
WILL EVOLVE ALONG ADVANCING WIND SHIFT ACROSS THE SLIGHT RISK REGION
IN ADDITION TO MAIN MCS AS IT PROPAGATES DOWNSTREAM IN ASSOCIATION
WITH STRONGER ASCENT AHEAD OF SHORTWAVE. LARGE HAIL AND DAMAGING
WINDS ARE THE PRIMARY SEVERE THREATS WITH THIS ACTIVITY. EWD EXTENT
OF SEVERE THREAT WILL BE LIMITED BY WEAKER INSTABILITY TO THE LEE OF
LAKE ERIE...DESPITE LARGE SCALE BACKGROUND SUPPORT FOR ORGANIZED
THUNDERSTORMS.
..DARROW.. 07/15/2007
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z
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