SWODY1
SPC AC 051245
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0745 AM CDT FRI SEP 05 2008
VALID 051300Z - 061200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE TX PANHANDLE AND WRN
OK...
...THERE IS A SLGT RISK OF SVR TSTMS OVER THE ERN CAROLINAS AND SERN
VA...
...SYNOPSIS...
BROAD UPPER TROUGH EXTENDS FROM THE NRN/CENTRAL ROCKIES EWD INTO THE
MID/UPPER MS VALLEY. A SERIES OF SHORTWAVE TROUGHS ARE ROTATING
THROUGH THIS LARGER SCALE TROUGH...WITH ONE OF THESE SYSTEMS AIDING
CONVECTION ACROSS WRN KS THIS MORNING. AT THE SURFACE...A WEAK
SURFACE TROUGH EXTENDED FROM NWRN MN SEWD TO A LOW PRESSURE CENTER
IN NERN NM. WHILE THE SURFACE TROUGH WILL WEAKEN AS IT SHIFTS EWD
INTO THE MS VALLEY...SURFACE LOW PRESSURE OVER ERN NM WILL RESULT IN
A STRONGER PRESSURE GRADIENT AND PRONOUNCED BAROCLINIC BOUNDARY TO
EXTEND FROM EAST CENTRAL NM NEWD INTO NWRN OK BY LATE AFTERNOON. IN
THE SERN STATES...THE LATEST NATIONAL HURRICANE CENTER FORECAST
SHIFTS TROPICAL STORM HANNA NWD INTO THE FAR ERN CAROLINAS LATE
TONIGHT.
...TX PANHANDLE/WRN OK...
LOW LEVEL JET MAY SUSTAIN LINE OF CONVECTION FROM SWRN KS INTO NWRN
OK THIS MORNING...BUT UPPER SHORTWAVE TROUGH PASSING NORTH OF AREA
SHOULD RESULT IN WEAKENING LOW LEVEL JET AND STORMS BY MID MORNING.
THEREAFTER...IT IS DIFFICULT TO TIME THE NEXT SHORTWAVE
TROUGH...THOUGH DIURNAL HEATING ALONG CONVERGENT BOUNDARY IS
EXPECTED TO PROVIDE SUFFICIENT LIFT FOR THUNDERSTORM DEVELOPMENT
LATE THIS AFTERNOON AND EVENING. COMBINATION OF SURFACE HEATING...
STEEP MID LEVEL LAPSE RATES/PER AMA 12Z SOUNDING...AND DEWPOINTS IN
THE MID/UPPER 50S SHOULD RESULT IN MODERATE INSTABILITY. ESELY
BOUNDARY LAYER WINDS...VEERING TO WLY AT 30 KT IN THE MID LEVELS
WILL YIELD DEEP LAYER SHEAR AT 40-50 KT. THIS AMOUNT OF SHEAR AND
INSTABILITY WILL BE SUPPORTIVE OF SUPERCELLS...WITH HAIL THE PRIMARY
THREAT. DESPITE RELATIVELY HIGH LCL/S...STRONGLY CURVED HODOGRAPHS
IN THE LOWEST 1 KM AND SEWD MOVING STORMS MAY PROVIDE SUFFICIENT
SRH...150 TO 250 M2/S2...FOR AN ISOLATED TORNADO OR TWO LATE THIS
AFTERNOON.
...ERN CAROLINAS/FAR SE VA...
BEFORE HANNA REACHES THE COAST LATE TONIGHT...CONVECTIVE RAIN BANDS
WILL SPREAD INTO THE REGION THROUGHOUT THE DAY. WIND FIELDS IN THE
LOWER 1-2 KM HAVE ALREADY INCREASED ACROSS ERN SC...WITH 30 KT OF
SHEAR INDICATED IN THE LOWEST KM ON THE CHS 12Z SOUNDING. WINDS
THROUGHOUT THE TROPOSPHERE WILL CONTINUE TO STRENGTHEN THROUGH THE
DAY AND BE FAVORABLE FOR ROTATING STORMS. THIS INCREASED
SHEAR...ALONG WITH A MORE MOIST BOUNDARY LAYER SPREADING
INLAND...WILL INCREASE THE POTENTIAL FOR A FEW TORNADOES WITHIN THE
NRN OUTER BANDS OF HANNA THIS AFTERNOON AND OVERNIGHT.
..IMY/SMITH.. 09/05/2008
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.
No comments:
Post a Comment