[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 270100
SWODY1
SPC AC 270058

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0758 PM CDT THU OCT 26 2006

VALID 270100Z - 271200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF SERN KS...ERN
OK...ERN TX INTO THE LOWER MS VALLEY...

...SRN KS THROUGH ERN OK AND NERN TX...

SURFACE ANALYSIS SHOWS A PACIFIC FRONT EXTENDING FROM A SURFACE LOW
IN N CNTRL OK SSWWD THROUGH N CNTRL AND SWRN TX ALONG WITH AN E-W
BOUNDARY ACROSS EXTREME NRN OK. A PRE-FRONTAL TROUGH EXTENDS FROM N
CNTRL TX NWD INTO SERN OK. A WARM FRONT SEPARATING RICHER LOW LEVEL
GULF MOISTURE FROM MODIFIED CP AIR EXTENDS FROM LA NWWD INTO NERN
TX.

THE SURFACE LOW WILL MOVE EWD THROUGH NRN OK OVERNIGHT WITHIN ZONE
OF ASCENT ASSOCIATED WITH EWD ADVANCING SHORTWAVE TROUGH AND ITS
ATTENDANT UPPER JET. TORNADIC STORMS THAT DEVELOPED EARLIER THIS
EVENING ACROSS SWRN KS ALONG THE E-W BOUNDARY HAVE WEAKENED. OTHER
STORMS ARE DEVELOPING FARTHER E ALONG/N OF THIS BOUNDARY ACROSS SERN
KS.  SOME POTENTIAL FOR AN ISOLATED TORNADO MAY EXIST NEXT COUPLE
HOURS AS STORMS DEVELOP ON THIS BOUNDARY. HOWEVER...SWLY ORIENTATION
OF THE STEERING FLOW RELATIVE TO THE SLIGHT SWD MOTION OF THE
BOUNDARY HAS RESULTED IN STORMS BEING UNDERCUT AND BECOMING ELEVATED
AS THEY CROSS ONTO THE COOL SIDE. THUS PRIMARY THREAT APPEARS TO BE
TRANSITIONING TO HAIL...BUT EVEN THE HAIL THREAT IS SOMEWHAT LIMITED
BY MODEST INSTABILITY.

SOME POTENTIAL STILL EXISTS FOR OTHER STORMS TO DEVELOP ACROSS ERN
OK. THE  NEAR SURFACE FLOW IS STILL BACKED TO SELY IN THIS REGION E
OF THE SURFACE LOW. WITH PRIMARY LOW LEVEL JET EXPECTED TO REMAIN SE
OF THIS AREA...LOW LEVEL HODOGRAPHS WILL NOT BE PARTICULARLY LARGE.
HOWEVER...SUFFICIENT VEERING...LOW LEVEL AND DEEP LAYER SHEAR EXIST
FOR A THREAT OF SUPERCELLS WITH HAIL AND LOW LEVEL
MESOCYCLONES...BUT CONDITIONAL UPON THE INITIATION OF SURFACE BASED
STORMS. THE INSTABILITY AXIS IN THIS REGION IS NARROW...AND AS THE
BOUNDARY LAYER CONTINUES TO COOL IT APPEARS MANY OF THE STORMS MAY
BE INITIATED WITHIN WEAK WARM ADVECTION REGIME ABOVE THE COOLER
BOUNDARY LAYER ACROSS EXTREME ERN OK INTO AR.

FARTHER S ACROSS NERN TX...OTHER STORMS ARE DEVELOPING WITHIN ZONE
OF ASCENT ALONG AND JUST E OF PRE-FRONTAL TROUGH WHERE THE
ATMOSPHERE REMAINS MODERATELY UNSTABLE WITH MLCAPE FROM 1000 TO 1500
J/KG. LOW LEVEL SHEAR IS WEAKER IN THIS REGION THAN FARTHER NORTH.
HOWEVER...EFFECTIVE SHEAR IN EXCESS OF 50 KT IS MORE THAN SUFFICIENT
FOR SUPERCELLS. SOME STORMS MAY ALSO EVOLVE INTO BOWING SEGMENTS.
PRIMARY THREAT APPEARS TO BE DAMAGING WIND...THOUGH SOME HAIL IS
POSSIBLE WITH THE STRONGER STORMS. OVERALL HAIL THREAT IS SOMEWHAT
LIMITED BY WEAK MID LEVEL LAPSE RATES.

...SERN TX THROUGH LA AND SRN MS...

STORMS ARE EXPECTED TO CONTINUE DEVELOPING WITHIN PLUME OF DEEP
MOISTURE FROM SERN TX INTO LA AND SRN MS OVERNIGHT. SWLY LOW LEVEL
JET IS FORECAST TO STRENGTHEN TO IN EXCESS OF 50 KT FROM SERN TX
INTO THE LOWER MS VALLEY. THIS WILL HELP TO ADVECT BOUNDARY LAYER
DEWPOINTS NEAR 70 FARTHER INLAND ACROSS LA IN WAKE OF RETREATING
WARM FRONT. THE INCREASING LOW LEVEL JET WILL RESULT IN FAVORABLE
0-1 KM HODOGRAPHS FOR A THREAT OF ISOLATED TORNADOES GIVEN INLAND
ADVECTION OF RICHER LOW LEVEL MOISTURE AS STORMS TRAIN FROM SW-NE
ALONG WARM CONVEYOR BELT. PRIMARY LIMITING FACTOR ARE THE WEAK LAPSE
RATES AND MARGINAL INSTABILITY.

..DIAL.. 10/27/2006