SWODY1
SPC AC 140044
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0744 PM CDT SUN SEP 13 2009
VALID 140100Z - 141200Z
...THERE IS A SLGT RISK OF SVR TSTMS TONIGHT OVER PART OF ERN MT...
...THERE IS A SLGT RISK OF SVR TSTMS TONIGHT OVER PORTIONS OF THE
CNTRL GULF STATES...
...ERN MT...
WIDELY SCATTERED TSTMS /INCLUDING SUPERCELLS/ HAVE DEVELOPED THIS
AFTERNOON AND EVENING WITHIN ZONE OF DEEP ASCENT ASSOCIATED WITH
UPPER LOW LIFTING NWD THROUGH THE REGION. 00Z GGW SOUNDING APPEARS
TO BE A REPRESENTATIVE PROXY FOR ONGOING STORMS...FEATURING STEEP
LAPSE RATES AND SBCAPE OF 1000-1500 J/KG AFTER MODIFYING SURFACE
DEWPOINT TO LOWER 50S. WHEN COUPLED WITH THE STRONG DYNAMIC FORCING
ATTENDANT TO UPPER SYSTEM AND SUFFICIENT VERTICAL SHEAR...
ENVIRONMENT OVER NERN MT IS EXPECTED TO REMAIN SUPPORTIVE OF SEVERE
STORMS FOR THE NEXT SEVERAL HOURS.
SEVERE THREAT SHOULD TEND TO DIMINISH FROM S-N TONIGHT AS STORMS
EITHER MOVE INTO SASKATCHEWAN OR WEAKEN WITH THE ONSET OF
RADIATIONAL COOLING. HAIL WILL REMAIN THE PRIMARY HAZARD WITH THE
MOST INTENSE STORMS.
...CNTRL GULF STATES...
EVENING MESOANALYSIS INDICATES PRIMARY WARM FRONT EXTENDING FROM
SURFACE LOW NEAR UTS NEWD THROUGH THE MS DELTA INTO NRN AL. A
MARINE OR SECONDARY WARM FRONT WAS ALSO ANALYZED FROM VICINITY OF
SURFACE LOW EWD INTO CNTRL LA AND THEN SEWD THROUGH SERN LA. AIR
MASS ALONG AND S OF THESE BOUNDARIES IS QUITE MOIST AND MODERATELY
UNSTABLE WITH 00Z LCH/LIX/JAN SOUNDINGS OBSERVING PW VALUES AOA 2
INCHES...CONTRIBUTING TO MLCAPE OF 1000-2000 J/KG.
CURRENT WATER VAPOR IMAGERY SUGGESTS THAT A VORTICITY MAXIMUM IS
LIFTING NWD THROUGH THE SABINE RIVER VALLEY. SUBTLE DARKENING OVER
THE NWRN GULF OF MEXICO MAY SUGGEST THE PRESENCE OF AN ADDITIONAL
IMPULSE/JET STREAK THAT COULD IMPACT THE REGION TONIGHT. THIS IS
GENERALLY CONSISTENT WITH LATEST RUC/GFS GUIDANCE WHICH INDUCE A
30-35 KT SLY LLJ OVER THE LOWER MS VALLEY IN RESPONSE TO THE ARRIVAL
OF THIS NEXT SYSTEM. 00Z LIX/LCH SOUNDINGS DO SHOW MODEST /30-35
KT/ MIDLEVEL FLOW...AND GIVEN THE ANTICIPATED INCREASE IN LOW-LEVEL
WINDS...WARM SECTOR HODOGRAPHS WILL BE FAVORABLE FOR ROTATING STORMS
CAPABLE OF A TORNADO OR TWO OVERNIGHT.
..MEAD.. 09/14/2009
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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