Thursday, September 13, 2007

DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 131238
SWODY1
SPC AC 131236

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0736 AM CDT THU SEP 13 2007

VALID 131300Z - 141200Z

..THERE IS A SLGT RISK OF SVR TSTMS ...

..SYNOPSIS...
NEXT IN A SERIES OF STRONG SHORTWAVE IMPULSES MOVING ALONG SRN
FRINGE OF BROAD CNTRL/ERN CANADIAN TROUGH WILL AMPLIFY E/SE FROM
MB/ND INTO CNTRL ONTARIO AND THE UPR GRT LKS THROUGH EARLY FRIDAY.
AS THIS OCCURS...WEAKER SRN STREAM DISTURBANCE NOW OVER W TX SHOULD
ACCELERATE E/SE TOWARD THE ARKLATEX AS REMNANTS OF HRCN HUMBERTO
LIFT NE INTO MS.

STRONG COLD FRONT WITH NRN PLNS SYSTEM SHOULD SURGE S ACROSS THE
PLNS AND E/SE INTO THE UPR GRT LKS/MID MS VLY. THE FRONT SHOULD
OVERTAKE LEE TROUGH OVER THE CNTRL HI PLNS AND REACH THE SRN PLNS
EARLY FRIDAY.

..LA/MS...
REMNANTS OF HRCN HUMBERTO EXPECTED TO MOVE STEADILY N/NE ACROSS
CNTRL LA TODAY AND INTO MS TONIGHT. THE RAIN SHIELD IN NE QUADRANT
OF SYSTEM HAS ALREADY SPREAD BEYOND WEAK SYNOPTIC FRONT ORIENTED
ROUGHLY WSW-ENE ACROSS FAR SRN LA AND MS. AS THE FRONT CONTINUES
SLOWLY NWD THROUGH THE DAY AND MODEST SFC HEATING SLIGHTLY
DESTABILIZES INFLOW ENVIRONMENT...EXPECT ISOLATED TORNADO THREAT TO
EXPAND SLOWLY ENE FROM S CNTRL LA INTO SE LA AND PERHAPS PARTS OF
SRN MS /REF MCD 1964/.

LATER TONIGHT...POTENTIAL WILL EXIST FOR REINTENSIFICATION OF
REMNANT TROPICAL CIRCULATION AS SYSTEM BEGINS TO INTERACT WITH
STRENGTHENING SWLY MID/UPR LVL FLOW OVERSPREADING THE LWR MS VLY.
ASSOCIATED INTENSIFICATION OF VERY MOIST LLJ COULD FOSTER
DEVELOPMENT OF LOW LVL ROTATION WITH EMBEDDED STORMS/SHOWERS IN ERN
QUADRANT OF SYSTEM. ANY SUSTAINED ACTIVITY IN SUCH AN ENVIRONMENT
COULD POSE A RENEWED THREAT FOR AN ISOLATED TORNADO OR TWO INTO
EARLY FRIDAY.

..WRN/CNTRL KS INTO OK PANHANDLE...
COLD FRONT SHOULD EXTEND FROM WRN WI...SW INTO SE NEB AND CNTRL KS
BY MID AFTERNOON. STRONG SFC HEATING SHOULD LEAD TO AN AXIS OF
STEEP LOW LVL LAPSE RATES BETWEEN THE FRONT AND AFOREMENTIONED LEE
TROUGH OVER CNTRL/SW KS. ENHANCED ASCENT ALONG THE LEE TROUGH
/ASSOCIATED WITH TEMPORAL STRENGTHENING AND VEERING LOW TO MID LVL
FLOW/ MAY SUPPORT DEVELOPMENT OF SCTD SFC OR NEAR SFC-BASED STORMS
ALONG THE TROUGH BY LATE IN THE DAY.

FAIRLY LIMITED MOISTURE SHOULD KEEP MLCAPE AOB 1000 J/KG.
NEVERTHELESS...STEEP LOW TO MID LVL LAPSE RATES COUPLED WITH 25-30
KT DEEP NW SHEAR SUGGEST POTENTIAL FOR A FEW STRONG STORMS. GIVEN
FOCUSED ASCENT ALONG THE TROUGH...THESE COULD MERGE INTO A SMALL
CLUSTER OR TWO AND YIELD LOCALLY DAMAGING WIND OR MARGINALLY SVR
HAIL THROUGH EARLY TONIGHT.

..NW KS/NE CO/SW NEB EARLY FRIDAY...
LATE TONIGHT AND EARLY FRIDAY...A FEW ELEVATED STORMS MAY FORM IN
POST-FRONTAL ENVIRONMENT ACROSS NW KS...NE CO AND SW NEB. HERE...
ISENTROPIC ASCENT WILL INCREASE ON SW FRINGE OF AMPLIFYING UPR
TROUGH. DEPENDING UPON THE ALTITUDE AND QUALITY OF THE PACIFIC
MOISTURE FEEDING THIS ACTIVITY...SUFFICIENT ELEVATED CAPE MAY EVOLVE
TO YIELD A SPOT OR TWO OF HAIL.

.CORFIDI/GUYER.. 09/13/2007

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@PO.UIUC.EDU with
"unsub wx-storm" in the body of your message. For more information write chris@lib.siu.edu.

No comments: