SPC AC 110535
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1235 AM CDT FRI JUN 11 2010
VALID 111200Z - 121200Z
...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN CO TO LOWER MI...
...MID/UPPER MS VALLEY...UPPER GREAT LAKES...
MCS IS SLOWLY ORGANIZING OVER NEB/SD EARLY THIS MORNING ALONG SRN
FRINGE OF STRONGER SWLY DEEP LAYER FLOW. THIS ACTIVITY IS EXPECTED
TO PROPAGATE INTO THE UPPER MS VALLEY REGION EARLY IN THE PERIOD
WITH A REMNANT CONVECTIVE VORT/SHORTWAVE TROUGH EXPECTED TO ENHANCE
THE THREAT FOR RENEWED DIURNAL ACTIVITY BY EARLY AFTERNOON NEAR THE
MN/IA BORDER. ADDITIONALLY...WARM ADVECTION WILL LIKELY DRIVE A FEW
ELEVATED THUNDERSTORM CLUSTERS ATOP COOLER AIRMASS FROM CNTRL
MN...EWD INTO NRN WI. IT/S NOT ENTIRELY CLEAR HOW MUCH SURFACE
BASED INSTABILITY WILL EXIST NEAR THE WARM FRONT PRIOR TO CONVECTIVE
DEVELOPMENT. EXTENSIVE CLOUD COVER AND THE PROSPECT FOR ONLY
MARGINAL LAPSE RATES SUGGEST SBCAPE WILL LIKELY REMAIN AOB 2000
J/KG. IF LEFTOVER CONVECTIVE DEBRIS FROM OVERNIGHT ACTIVITY DOES
NOT IMPEDE SFC HEATING THEN STRONGER INSTABILITY WILL EXIST FOR A
POTENTIALLY MORE ROBUST CONVECTIVE SCENARIO ACROSS THIS REGION.
OTHERWISE...MODEST DEEP LAYER SHEAR SHOULD SUPPORT ORGANIZED
MULTI-CELL CLUSTERS AND PERHAPS A FEW SUPERCELLS. HAIL AND LOCALLY
DAMAGING DOWNBURSTS ARE THE PRIMARY SEVERE RISKS.
...CENTRAL PLAINS...
CONVECTIVE OUTFLOW/SFC FRONT HAS SURGED ACROSS THE HIGH PLAINS OF WY
AND WILL SOON PLUNGE SOUTH INTO CO AS PRESSURES BEGIN TO RISE ACROSS
THE NRN HIGH PLAINS. NELY UPSLOPE FLOW WILL DEEPEN ACROSS CO DURING
THE DAY WITH BOUNDARY LAYER MOISTURE EXPECTED TO BE FORCED AGAINST
THE EAST SLOPES TO NEAR THE NM STATE LINE BY LATE AFTERNOON.
THUNDERSTORMS WILL DEVELOP BY MID AFTERNOON OVER THE HIGHER
ELEVATIONS BENEATH MODERATE SSWLY FLOW ALOFT FROM ERN UT INTO CNTRL
CO. BY 20-21Z IT APPEARS THUNDERSTORMS WILL LIKELY BEGIN TO DEVELOP
ALONG THE FRONT RANGE OF CNTRL/SRN CO BEFORE ORGANIZING WITHIN
FAVORABLY SHEARED ENVIRONMENT FOR SUPERCELLS. FORECAST SOUNDINGS
STRONGLY SUGGEST ANY STORMS THAT EVOLVE SOUTH OF THE PALMER DIVIDE
ACROSS ERN CO INTO SWRN KS COULD PRODUCE VERY LARGE HAIL...IN EXCESS
OF 2 INCHES. THIS ACTIVITY SHOULD SPREAD/DEVELOP NEWD ALONG FRONTAL
ZONE INTO KS DURING THE EVENING HOURS. AN MCS WILL LIKELY EVOLVE
ACROSS KS AS LLJ STRENGTHENS ACROSS THE SRN PLAINS INTO KS DURING
THE OVERNIGHT HOURS. LARGE HAIL WILL BE THE PRIMARY SEVERE THREAT
WITH MOST OF THIS ACTIVITY...THOUGH ISOLATED TORNADOES ARE CERTAINLY
POSSIBLE WITH SUPERCELLS ACROSS THE HIGH PLAINS THROUGH EARLY
EVENING.
..DARROW/GARNER.. 06/11/2010
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
|
