SWODY1
SPC AC 161932
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0232 PM CDT TUE OCT 16 2007
VALID 162000Z - 171200Z
..THERE IS A SLGT RISK OF SVR TSTMS TONIGHT ACROSS PARTS OF THE SRN
HIGH PLAINS....
..UPPER MS VLY/GREAT LAKES REGION...
AN OCCLUDED SURFACE FRONT IS BECOMING THE FOCUS FOR WEAK
DESTABILIZATION THIS AFTERNOON....AS A MID-LEVEL THERMAL TROUGH
OVERSPREADS A NARROW TONGUE OF LOW-LEVEL MOISTURE ORIENTED ALONG THE
BOUNDARY. WEAK THUNDERSTORM ACTIVITY HAS BEEN OCCURRING ACROSS
PARTS OF WESTERN WISCONSIN...NEAR A NEW DEVELOPING MID-LEVEL
CIRCULATION CENTER. AND...A WINDOW OF OPPORTUNITY STILL EXISTS FOR
SCATTERED ADDITIONAL STORMS SOUTHEASTWARD ALONG THE INSTABILITY
AXIS...ACROSS CENTRAL WISCONSIN INTO SOUTHWEST LOWER
MICHIGAN/NORTHERN INDIANA LATE THIS AFTERNOON. DEEP LAYER SHEAR IS
WEAK...BUT 25-30 KT MEAN SOUTHERLY FLOW FIELDS AND COOL
THERMODYNAMIC PROFILES COULD SUPPORT A FEW STORMS WITH SMALL
HAIL/GUSTY WINDS. THIS SHOULD GENERALLY BE CONFINED TO THE 20-23Z
TIME FRAME...WITH CONVECTION WEAKENING THEREAFTER DUE TO
STABILIZATION ASSOCIATED WITH THE LOSS OF DAYTIME HEATING.
..SOUTHERN/CENTRAL HIGH PLAINS...
WEAK DESTABILIZATION IS ONGOING ACROSS WESTERN TEXAS...AS LOW-LEVEL
MOISTURE BEGINS TO RETURN NORTHWARD...IN ADVANCE OF A LEAD UPPER
IMPULSE ASSOCIATED WITH THE STRONG UPPER JET NOSING INTO THE
SOUTHWESTERN STATES. DEEP LAYER SHEAR BENEATH 40+ KT CYCLONIC
SOUTHWESTERLY MID-LEVEL FLOW IS ALREADY MODERATELY STRONG. AND...
IT APPEARS POSSIBLE THAT AN ISOLATED BOUNDARY LAYER BASED
THUNDERSTORM OR TWO COULD FORM LATE THIS AFTERNOON OR EARLY EVENING.
IF THIS OCCURS...CAPE OF 500-1000 J/KG IN THE PRESENCE OF FAVORABLE
SHEAR FOR UPDRAFT ROTATION COULD SUPPORT A LIMITED SEVERE
THREAT...WITH THE RISK FOR LARGE HAIL/DAMAGING WIND GUSTS.
HOWEVER...PRIMARY CONVECTIVE DEVELOPMENT IS EXPECTED TO AWAIT
STRENGTHENING LARGE-SCALE FORCING WITH THE APPROACH OF THE UPPER
SYSTEM LATER THIS EVENING/OVERNIGHT. ACTIVITY LIKELY WILL BE
ELEVATED IN THE STRONGER LOWER/MID TROPOSPHERIC WARM ADVECTION
REGIME FROM THE TEXAS SOUTH PLAINS INTO PARTS OF THE EASTERN
PANHANDLE/WESTERN OKLAHOMA. BUT...INSTABILITY MAY BE ENOUGH FOR AT
LEAST A CONTINUING RISK OF LARGE HAIL.
.KERR.. 10/16/2007
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