[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 261210
SWODY1
SPC AC 261209

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0709 AM CDT THU OCT 26 2006

VALID 261300Z - 271200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE S CENTRAL
U.S. INTO AR/LA....

...SYNOPSIS...
STRONG MID/UPPER LEVEL LOW CURRENTLY OVER THE SRN UT/CO BORDER WILL
MOVE EWD OVER THE NWRN TX PANHANDLE BY LATER THIS AFTERNOON INTO
NERN OK BY THE END OF THE PERIOD.  SURFACE LOW CONTINUES TO DEEPEN
OVER SERN CO AT THIS TIME AND WILL BE OVER NWRN OK BY 21Z INTO SWRN
MO/NWRN AR BY FRI MORNING.  A DRYLINE EXTENDS FROM JUST SW OF ICT
THIS MORNING SWWD JUST W OF MAF WITH A WARM FRONTAL BOUNDARY FROM S
CENTRAL KS SEWD THROUGH SERN OK INTO SERN LA.  ALSO...A COLD FRONT
EXTENDS FROM THE SERN CO LOW SWD AND SWWD THROUGH SERN AND S CENTRAL
NM AND W CENTRAL AZ.  THIS FRONTAL SYSTEM WILL MOVE EWD AS WELL
THROUGH TONIGHT ENHANCING UPWARD ASCENT AND THUNDERSTORMS ACROSS
PARTS OF KS...CENTRAL AND ERN OK AND TX INTO PARTS OF MO AND AR AND
THE LOWER MS VALLEY DURING THE PERIOD.

...SERN KS/NERN OK INTO SWRN MO/NWRN AR...

VERY STRONG RIBBON OF UPPER LEVEL WINDS OF 130-150 KT WILL EXTEND
FROM CENTRAL AZ INTO CENTRAL OK AND NRN TX THROUGH THIS
EVENING...THEN INTO SRN MO/NRN AR BY FRIDAY MORNING.  CLOSE ANALYSIS
OF THESE WINDS SHOW THAT THE NRN BRANCH OF THIS JET WILL BE FROM
SERN AZ INTO SERN KS BY THIS AFTERNOON...WHILE THE SRN BRANCH
EXTENDS FROM THE BAJA SPUR INTO CENTRAL TX.  THUS...THERE WILL BE
SOME UPPER LEVEL DIVERGENCE FROM CENTRAL OK SWD INTO CENTRAL TX TO
ENHANCE UPWARD ASCENT ASSOCIATED WITH COLD FRONT/DRYLINE COMBINATION
DURING THE AFTERNOON INTO TONIGHT.  WINDS AT 500 MB REFLECT THIS
STRUCTURE AS WELL WITH A 100 KT JET STREAK FROM SERN NM NEWD INTO S
CENTRAL KS FOR THE NRN BRANCH AS THE SRN BRANCH OF 60-80 KT EXTENDS
FROM THE TX BIG BEND INTO NERN TX.  LOW LEVEL JET AXIS IS ANALYZED
FARTHER E OUT AHEAD OF THE APPROACHING SYSTEM AS 40-50 KT WINDS ARE
FORECAST FROM SWRN LA INTO WRN KY BY LATER THIS AFTERNOON. 
BUT...STRONG WLY FLOW AT LOW LEVELS INCREASE TONIGHT WHICH WILL AID
IN LOW LEVEL FRONTAL FORCING ACROSS ERN KS INTO ERN TX.

THIS TYPE OF KINEMATIC STRUCTURE LOOKS TO SET UP MORE OF A BIMODAL
TYPE SITUATION OVER THE PLAINS LATER TODAY.  MODELS INDICATE THAT
MID LEVEL LAPSE RATES OVER SERN KS INTO THE NERN QUARTER OF OK WILL
BE AROUND 7 C/KM WITH MLCAPE VALUES OF 1200-1600 J/KG THIS
EVENING...AND DEEP LAYER SHEAR OF 50-70 KT.  THUS...THIS AREA WILL
BE ONE AREA TO CONSIDER FOR HAIL AND DAMAGING WINDS AS THE FRONTAL
BOUNDARY/ASSOCIATED SQUALL LINE DEVELOPS ALONG/JUST AHEAD OF THE
FRONT. ISOLATED TORNADOES WOULD ALSO NEED TO BE CONSIDERED ACROSS
THIS AREA WITH THAT MUCH DEEP LAYER SHEAR AND WITH LCL/LFC LEVELS
BEING AT/JUST BELOW 850 MB.

...SERN OK INTO NERN AND E CENTRAL TX...

THIS WILL BE THE SECOND AREA IN THIS SITUATION AS THE SUBTLE SRN
STREAM EXTENDS EWD ACROSS THIS REGION LATE THIS AFTERNOON AND EARLY
TONIGHT.  THERE COULD BE A FEW DISCRETE SUPERCELLS DEVELOP AHEAD OF
THE COLD FRONT OVER PARTS OF SERN OK INTO NERN AND E CENTRAL TX
WHERE FORECAST SOUNDINGS SHOW A BIT MORE INSTABILITY WITH MLCAPE
NEAR 2000 J/KG AND CLOSER LCL/LFC LEVELS JUST BELOW 850 MB.  THIS
AREA WILL ALSO BE IN A MORE FAVORABLE EXIT REGION OF THE UPPER LEVEL
JET STREAK TO ENHANCE ASCENT WITH DEEP LAYER SHEAR INCREASING TO
AROUND 50 KT BY EARLY TONIGHT. AGAIN LARGE HAIL AND DAMAGING WINDS
WILL BE THE MAIN THREATS...BUT A FEW TORNADOES COULD OCCUR LATER
THIS AFTERNOON/EARLY TONIGHT WHERE THERE IS BETTER COUPLING OF
LOW/MID LEVEL WINDS.

MAIN THREAT OF DAMAGING WINDS WILL BECOME MORE LIKELY AFTER EARLY
THIS EVENING AS MAIN VORTEX MOVES THROUGH OK AND THERE IS AN
INCREASE IN WLY LOW LEVEL FLOW BEHIND THE MAIN FRONTAL PUSH THAT
MOVES INTO SWRN MO INTO CENTRAL AR LATER TONIGHT.

..MCCARTHY/GRAMS.. 10/26/2006