SPC AC 030511
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1211 AM CDT FRI SEP 03 2010
VALID 031200Z - 041200Z
...NO SVR TSTM AREAS FORECAST...
...SYNOPSIS...
PROGRESSIVE NRN-STREAM PATTERN FCST TO CONTINUE ALOFT THROUGH
PERIOD...LED BY STG SHORTWAVE TROUGH NOW ANALYZED SWD FROM LOW OVER
NRN MN. ASSOCIATED MID-UPPER CYCLONE IS FCST TO DEEPEN
SOMEWHAT...ENLARGE...AND MOVE EWD TO ENEWD ACROSS NRN ONT THROUGH
PERIOD. MEANWHILE TRAILING TROUGH SHOULD SHIFT EWD TO POSITION OVER
LH...CENTRAL OH...AND EXTREME WRN NC BY 4/12Z. AS THIS
OCCURS...RELATED STG COLD FRONT -- ANALYZED ATTM FROM WRN LOWER MI
ACROSS SRN IL...NRN AR...SERN OK...W-CENTRAL TX -- WILL MOVE EWD
THROUGH OH VALLEY...AND SEWD OVER CENTRAL/SRN APPALACHIANS...LOWER
MS VALLEY AND S TX.
...NRN APPALACHIANS TO S TX...
WIDELY SCATTERED TSTMS IN CLUSTERS AND SMALL BANDS ARE EXPECTED TO
FORM INVOF FRONTAL ZONE...PRIMARILY DURING AFTERNOON INTO EARLY
EVENING. NARROW CORRIDOR OF FAVORABLE MOISTURE/BUOYANCY IS EXPECTED
TO DEVELOP DURING PERIOD OF STRONGEST HEATING ALONG/AHEAD OF FRONT
FROM UPPER OH VALLEY REGION SWWD ACROSS LOWER MS VALLEY...WITH
RELATIVELY WEAK MID-UPPER LEVEL LAPSE RATES LIMITING BOTH DEPTH AND
MAGNITUDE OF BUOYANCY. THEREFORE...DURATION OF THUNDER POTENTIAL
WILL BE RELATIVELY BRIEF IN THAT CORRIDOR.
FARTHER SW ACROSS W GULF COASTAL PLAIN TO RIO GRANDE
VALLEY...SOMEWHAT STEEPER LAPSE RATES AND STRONGER SFC HEATING AND
SFC DEW POINTS LOW-MID 70S F WILL BOOST MLCAPE TO 1500-2000 J/KG
RANGE IN PREFRONTAL AIR MASS. CONVECTION MAY DEVELOP EITHER IN
FRONTAL ZONE OR ALONG PREFRONTAL SEA BREEZE/OUTFLOW BOUNDARIES.
MAIN LIMITING FACTOR WILL BE LIGHT...ENELY-NELY WINDS AHEAD OF FRONT
WHICH WILL ACT TO LIMIT BOTH CONVERGENCE AND VERTICAL SHEAR. WHILE
A FEW TSTMS MAY PRODUCE STG GUSTS OR SUB-SVR HAIL...SVR POTENTIAL
ATTM APPEARS TOO WEAK AND CONDITIONAL TO DRAW AREA OF AOA 5%
UNCONDITIONAL PROBABILITIES.
..EDWARDS/STOPPKOTTE.. 09/03/2010
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
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