SPC AC 051237
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0737 AM CDT TUE SEP 05 2006
VALID 051300Z - 061200Z
...NO SVR TSTM AREAS FORECAST...
...SYNOPSIS...
MID/UPPER-LEVEL LOW OVER NRN IL IS FORECAST TO SHIFT ESEWD AND
GRADUALLY EVOLVE INTO A POSITIVELY TILTED OPEN WAVE FROM THE OH
VALLEY SWD INTO THE CENTRAL GULF STATES. PRIMARY BAROCLINIC
ZONE...SITUATED THIS MORNING FROM AL NEWD INTO SERN VA...WILL SHIFT
SEWD THIS AFTERNOON AND TONIGHT AS THE UPPER TROUGH APPROACHES FROM
THE WEST. MOISTURE TRAPPED UNDER UPPER RIDGE IN THE WEST WILL RESULT
IN SCATTERED THUNDERSTORMS...MAINLY DURING THE AFTERNOON AND OVER
THE HIGHER TERRAIN. ALTHOUGH THE SEVERE POTENTIAL WILL BE LOW ACROSS
THE CONUS DUE TO LIMITED INSTABILITY AND WEAK FORCING...A FEW
MARGINAL SEVERE WEATHER EVENTS ARE POSSIBLE ACROSS PORTIONS OF THE
OH VALLEY...GA NEWD INTO SRN VA AND IN FOOTHILLS OF SRN CO INTO NERN
NM.
...OH VALLEY...
SCATTERED THUNDERSTORMS CONTINUED EARLY THIS MORNING...EAST AND
SOUTH OF THE UPPER LOW. THIS CONVECTION WILL SPREAD SLOWLY EWD AND
INTENSIFY SLIGHTLY AS DIURNAL HEATING RESULTS IN SBCAPES UP TO 1000
J/KG. GIVEN COLD 500 MB TEMPERATURES FROM -14 TO -16C...MARGINALLY
SEVERE HAIL IS POSSIBLE WITH A FEW STORMS. HOWEVER...THE RELATIVELY
WEAK INSTABILITY AND MARGINAL VERTICAL SHEAR WILL LIMIT THE SEVERE
POTENTIAL.
...GA NEWD INTO SRN VA...
SURFACE ANALYSIS INDICATES THAT A WEAK WAVE WAS LOCATED ALONG THE
FRONT IN NRN GA. THE MODELS LIFT THIS FEATURE NEWD AND OFF THE SERN
VA COAST TONIGHT. THE SEWD PUSH OF THE FRONT COMBINED WITH 30-60M
HEIGHT FALLS SHOULD PROVIDE SUFFICIENT LIFT FOR NUMEROUS
THUNDERSTORMS TO DEVELOP ALONG AND EAST OF THE FRONT TODAY AND INTO
THE EVENING HOURS. ALTHOUGH THE BOUNDARY LAYER WILL REMAIN QUITE
MOIST EAST OF THE FRONT WITH DEWPOINTS IN THE LOWER 70S...WEAK LAPSE
RATES SHOULD LIMIT SBCAPES TO 1000-2000 J/KG. ALSO...THE STRONGER
MID AND HIGH-LEVEL WINDS ASSOCIATED WITH THE UPPER TROUGH WILL
REMAIN BEHIND THE COLD FRONT...WITH THE WARM SECTOR DEEP LAYER SHEAR
EXPECTED TO ONLY RANGE FROM 20-30 KT. UNIDIRECTIONAL SWLY WINDS
ABOVE THE BOUNDARY LAYER SUGGESTS SOME STORMS MAY DEVELOP INTO SMALL
LINES WITH THE POSSIBILITY OF ISOLATED STRONG/SEVERE WIND GUSTS.
HOWEVER...THE COMBINATION OF WEAK FORCING AND POOR LAPSE RATES
SHOULD LIMIT THE SEVERE POTENTIAL.
...EXTREME SOUTH CENTRAL CO AND NERN NM...
LOW-LEVEL ESELY UPSLOPE FLOW SHOULD MAINTAIN DEWPOINTS IN THE 40S TO
LOWER 50S...DESPITE STRONG MIXING. STRONG HEATING AND STEEP MID
LEVEL LAPSE RATES SHOULD YIELD AFTERNOON SBCAPES NEAR 500 J/KG. THE
ELEVATED HEAT SOURCE WILL AID IN LATE AFTERNOON INITIATION OVER THE
HIGHER TERRAIN OF FAR SRN CO AND NERN NM. ONCE STORMS FORM...STRONG
LOW-LEVEL VEERING BENEATH 20-30 KT NNWLY MID-LEVEL WINDS WILL RESULT
IN SUFFICIENT VERTICAL SHEAR FOR STORMS TO ROTATE. ALTHOUGH HAIL IS
POSSIBLE WITH A STORM OR TWO...THE MEAGER MOISTURE AND INSTABILITY
IS EXPECTED TO LIMIT THE NUMBER OF STORMS AND OVERALL SEVERE WEATHER
THREAT.
..IMY/JEWELL.. 09/05/2006
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
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