SPC AC 260106
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0806 PM CDT FRI AUG 25 2006
VALID 260100Z - 261200Z
...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE SCNTRL
PLAINS...
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS ERN UT AND NWRN CO...
...THERE IS A SLGT RISK OF SVR TSTMS OVER SWRN NY AND NWRN PA...
...SCNTRL PLAINS...
QUASI-STATIONARY FRONTAL ZONE BISECTS THE SCNTRL PLAINS FROM THE TX
PNHDL NEWD ACROSS KS...TO NRN MO. WIDESPREAD DEEP CONVECTION HAS
DEVELOPED IN VARIOUS REGIMES ACROSS THIS REGION...FROM HOT AND
DEEPLY MIXED BOUNDARY LAYER AIR MASS AHEAD OF THE FRONT...OVER NRN
OK/SRN KS...TO STRONGLY UNSTABLE POST-FRONTAL AIR MASS...ALONG THE
NEB/KS BORDER. MOST INTENSE AND LONG-LIVED STORMS HAVE BEEN ON OR
NEAR THE FRONTAL WIND SHIFT FROM SWRN KS TO NWRN MO. LARGE SCALE
MID/UPPER LEVEL DIFFLUENCE ATOP ABUNDANTLY MOIST/UNSTABLE AIR MASS
ACROSS THE BOUNDARY SHOULD SUSTAIN VIGOROUS STORMS WITH HAIL AND
HIGH WINDS WELL INTO THE NIGHT. GENERALLY WEAK LOW LEVEL FLOW TOPPED
BY 30KT MID LEVEL FLOW WAS RESULTING IN SUFFICIENT BULK SHEAR FOR
UPDRAFT PERSISTENCE AND ROTATION. MAGNITUDE OF LOW LEVEL CAPE AND
ENHANCED SHEAR NEAR AND NORTH OF THE SURFACE FRONT/WIND SHIFT COULD
SUPPORT A BRIEF TORNADO OR TWO FROM CELLS TRACKING NEAR/ALONG THE
FRONT.
...ERN UT/NWRN CO...
UPPER TROUGH OVER THE NRN GREAT BASIN WILL CONTINUE TO DIG SEWD
TONIGHT AND INDUCE WIDESPREAD ASCENT ACROSS THE NCNTRL ROCKIES.
NUMEROUS HIGH-BASED STORMS IN LOW-CAPE BUT MODESTLY SHEARED
ENVIRONMENT WILL CONTINUE TO POSE A THREAT OF MARGINALLY SEVERE HAIL
AND DAMAGING DOWNBURSTS. THIS ACTIVITY WILL GRADUALLY WANE THROUGH
LATE EVENING AS LOW LEVELS STABILIZE AND BOUNDARY LAYER LAPSE RATES
WEAKEN.
...WRN NY/NWRN PA...
TSTMS HAVE RECENTLY INCREASED AHEAD OF LOW-AMPLITUDE SHORT WAVE
IMPULSE TRACKING SEWD ACROSS LAKES ERIE/ONTARIO. THIS IMPULSE WAS
LIKELY AIDING DEEP LAYER ASCENT AND DESTABILIZATION IN A NARROW ZONE
FROM NWRN PA INTO WRN NY WHERE DIAGNOSTIC DATA AND EVENING SOUNDINGS
SUGGEST STRONG DEEP LAYER SHEAR EXISTS. SOUNDINGS ALSO DEPICT
RELATIVELY WEAK MID LEVEL LAPSE RATES BUT MAY NOT BE TRULY SAMPLING
THE SMALL SCALE ENVIRONMENT BETWEEN PIT AND BUF WHERE CONVECTION IS
EXPECTED TO PERSIST. GIVEN LATEST TRENDS IN REFLECTIVITY...AND MODEL
GUIDANCE SUGGESTING AN INCREASE IN CONVECTION ACROSS THE NY/PA
BORDER THROUGH LATE TONIGHT...A SMALL SLGT RISK WILL BE MAINTAINED.
MARGINALLY SEVERE HAIL APPEARS TO BE THE PRIMARY HAZARD AT THIS TIME
BUT A BRIEF SEVERE WIND GUST OR TORNADO COULD OCCUR IF A ROBUST CELL
CAN TRACK PREFERENTIALLY ALONG THE SURFACE BOUNDARY SITUATED ACROSS
NWRN PA/WRN NY.
...UPPER MIDWEST...
DESPITE STRONG INSTABILITY AND FOCUSED LOW LEVEL FORCING ALONG THE
FRONT...AND NEAR WEAK FRONTAL WAVE OVER ERN IA/NRN IL...TSTMS ACROSS
THESE AREAS HAVE REMAINED POORLY ORGANIZED SINCE EARLY EVENING. WEAK
LARGE SCALE SUPPORT /SHORT WAVE RIDGING ALOFT/ AND SLOW DIURNAL
DECREASE IN INSTABILITY SHOULD INHIBIT A MORE WIDESPREAD SEVERE
THREAT. AN ISOLATED HAIL AND/OR WIND EVENT REMAINS POSSIBLE GIVEN
FRONTAL LIFT OCCURRING IN MOIST AND UNSTABLE ENVIRONMENT. HOWEVER...
OVERALL PROBABILITY DOES NOT WARRANT CONTINUING A SLGT RISK IN THIS
AREA.
..CARBIN.. 08/26/2006
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z
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