DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 120556
SWODY1
SPC AC 120554

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1254 AM CDT SAT OCT 12 2013

VALID 121200Z - 131200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
BROAD LARGE-SCALE CYCLONIC FLOW ALOFT WILL ENCOMPASS MUCH OF THE
CENTRAL/WRN CONUS. AN EMBEDDED SHORTWAVE UPPER TROUGH WILL SHIFT OUT
OF THE NRN PLAINS AND INTO THE UPPER GREAT LAKES WHILE ACQUIRING A
NEGATIVE TILT...WITH GRADUAL MIDLEVEL HEIGHT RISES OCCURRING
UPSTREAM ACROSS THE GREAT PLAINS. ANOTHER SHORTWAVE UPPER TROUGH
INITIALLY OVER THE PAC NW WILL DIG SWD TOWARDS THE WRN GREAT BASIN.
AT THE SFC...SRN EXTENSION OF A CENTRAL CONUS COLD FRONT WILL BECOME
QUASI-STATIONARY OVER THE SRN PLAINS...WITH RICH GULF MOISTURE
ADVECTING NWD ACROSS TX AND THE LOWER MS VALLEY.

...SOUTHERN PLAINS AND THE ARKLATEX...
SCATTERED TSTMS SHOULD BE ONGOING AT THE START OF THE PERIOD ACROSS
PARTS OF THE ARKLATEX FROM OVERNIGHT CONVECTION THAT FORMED IN
ASSOCIATION WITH A CNTRL CONUS SHORTWAVE UPPER TROUGH. IN IT/S
WAKE...A SLOW-MOVING COLD FRONT/OUTFLOW BOUNDARY WILL LIKELY BE
POSITIONED ACROSS SERN MO AND CNTRL AR...WITH THE FRONTAL SEGMENT
NEAR THE RED RIVER BECOMING QUASI-STATIONARY BY THE AFTERNOON. A
VERY MOIST AIR MASS WILL BE PRESENT S OF THE BOUNDARY WITH SFC
DEWPOINTS IN THE UPPER 60S TO LOWER 70S F. UNCERTAINTY EXISTS ABOUT
THE COVERAGE OF CLOUDINESS INVOF THE FRONT...BUT WITHIN POCKETS OF
STRONGER HEATING THE AIR MASS MAY BECOME MODERATELY UNSTABLE
/ESPECIALLY ACROSS N TX/ SHOULD SFC TEMPERATURES REACH THE MID-UPPER
80S F.

TSTM INITIATION REMAINS UNCERTAIN DURING THE AFTERNOON DUE TO
MIDLEVEL HEIGHT RISES IN THE WAKE OF THE AFOREMENTIONED SHORTWAVE
TROUGH...WEAK LOW-LEVEL CONVERGENCE FORECAST ALONG THE FRONT...AND
THE DEGREE OF DESTABILIZATION THAT OCCURS. EVEN IF TSTM DEVELOPMENT
OCCURS DURING THE AFTERNOON...COVERAGE SHOULD REMAIN FAIRLY ISOLATED
GIVEN THE AFOREMENTIONED LIMITING FACTORS...WHICH IS THE SCENARIO
ALSO PORTRAYED BY MOST RECENT HIGH-RESOLUTION MODEL GUIDANCE.
STILL...AN ISOLATED SVR THREAT COULD ACCOMPANY ANY ORGANIZED
MULTICELL STORMS THAT CAN DEVELOP GIVEN EFFECTIVE SHEAR VALUES NEAR
30 KT AND AN ANOMALOUSLY MOIST AIR MASS.

..ROGERS/GARNER.. 10/12/2013

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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.