SPC AC 270045
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0745 PM CDT WED SEP 26 2007
VALID 270100Z - 271200Z
...NO SVR TSTM AREAS FORECAST...
...OH VALLEY THROUGH NERN STATES...
EARLY THIS EVENING A QUASISTATIONARY FRONT EXTENDS FROM THE LOWER
GREAT LAKES REGION SWWD THROUGH THE OH AND LOWER MS VALLEYS. WIDELY
SCATTERED STORMS PERSIST FROM SERN OH THROUGH SERN MAINE WHERE THE
PRE-FRONTAL WARM SECTOR IS CHARACTERIZED BY WEAK MID LEVEL LAPSE
RATES AND MARGINAL INSTABILITY. A VORTICITY MAXIMUM WAS INDICATED
MOVING NEWD THROUGH OH. MODERATE SWLY MID-UPPER FLOW DOWNSTREAM FROM
THIS FEATURE IS CONTRIBUTING TO 30 TO 35 KT SWLY EFFECTIVE SHEAR
SUFFICIENT FOR SOME STORMS TO DEVELOP MID LEVEL UPDRAFT ROTATION.
STORMS OVER N CNTRL PA AND SWRN NY HAVE ALSO EXHIBITED BOWING
STRUCTURES. ISOLATED DAMAGING GUSTS AND MARGINALLY SEVERE HAIL WILL
REMAIN THE PRIMARY THREATS THIS EVENING. OVERALL TREND SHOULD BE FOR
STORMS TO GRADUALLY DECREASE IN INTENSITY AS THE BOUNDARY LAYER
STABILIZES.
...SRN HIGH PLAINS...
WRN EXTENTION OF STATIONARY FRONT EXTENDS THROUGH SRN AND WRN OK.
DRYLINE EXTENDS FROM E CNTRL NM NEWD INTO THE TX PANHANDLE. WIDELY
SCATTERED STORMS THAT DEVELOPED IN THE VICINITY OF THESE BOUNDARIES
CONTINUE FROM WRN TX NEWD INTO WRN OK. STORMS OVER WRN TX HAVE
BECOME OUTFLOW DOMINANT...WHILE STORMS OVER WRN OK AND THE NERN TX
PANHANDLE APPEAR TO BE A LITTLE MORE ORGANIZED AS SUPERCELLS WHERE
MID-UPPER FLOW AND EFFECTIVE SHEAR IS SOMEWHAT STRONGER WITH LEFT
SPLITS OBSERVED DURING THE PAST HOUR. ISOLATED LARGE HAIL AND STRONG
WIND GUSTS WILL REMAIN THE PRIMARY THREATS. ACTIVITY APPEARS TO BE
MOSTLY DIURNALLY DRIVEN...AND A GRADUAL DECREASE IN INTENSITY IS
EXPECTED AS THE BOUNDARY LAYER STABILIZES.
..DIAL.. 09/27/2007
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z
|
