[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 210557
SWODY1
SPC AC 210556

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1256 AM CDT THU SEP 21 2006

VALID 211200Z - 221200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE
CNTRL/SRN PLAINS AND OZARKS...

...CNTRL-SRN PLAINS AND OZARKS...
POTENT UPPER LOW CURRENTLY MOVING INTO THE SRN ROCKIES WILL SPIN EWD
TO KS BY FRI AFTN...THEN DEAMPLIFY AS IT SWINGS NEWD INTO THE MO VLY
BY 12Z SATURDAY.  SFC LOW DEVELOPING OVER SERN CO WILL DEVELOP INTO
KS ON FRI WITH A DRYLINE/FRONT SWEEPING EWD ACROSS ERN KS...CNTRL/
ERN OK AND CNTRL TX DURING THE AFTN/EVE.  A WARM FRONT...MARKING THE
LEADING EDGE OF MORE QUALITY BOUNDARY LAYER MOISTURE...WILL BEGIN TO
LIFT NWD THROUGH ERN TX AND THE LWR MS VLY FRI AND FRI NIGHT.  

CONVECTION AND CLOUDS ASSOCD WITH A WARM CONVEYOR WILL BE ONGOING
FROM N TX NWD INTO KS AND NEB AT THE START OF THE PERIOD.  THIS
CONVEYOR SHOULD SHIFT EWD INTO THE OZARKS BY AFTN...WITH POTENTIAL
FOR CLEARING TO DEVELOP UPSTREAM AHEAD OF THE APPROACHING DRYLINE/
FRONT. 

MODIFIED GULF MOISTURE CHARACTERIZED BY SFC DEW POINTS IN THE 50S
WILL ADVECT OR BE MAINTAINED ACROSS CNTRL AND ERN SECTIONS OF KS/OK
THROUGH FRI AFTN.  MORE ROBUST MOISTURE /DEW POINTS IN THE 60S TO
LWR 70S/ WILL ARRIVE ACROSS NERN TX...SERN OK AND SWRN AR LATE FRI
AFTN/EVE. 

STRONGEST LARGE SCALE FORCING FOR ASCENT ASSOCD WITH THE APPROACHING
SYSTEM /SWLY H5 JET 75+ KTS/ WILL TRANSLATE ACROSS KS/NRN OK WHERE
INSTABILITY WILL BE TEMPERED BY MODEST MOISTURE.  MAGNITUDE OF
FORCING...HOWEVER...MAY COMPENSATE AND TSTMS WILL LIKELY INITIATE
EARLY FRI AFTN FROM CNTRL KS SWD INTO CNTRL OK.  VERTICAL SHEAR WILL
BE SUFFICIENT FOR SUPERCELLS.  THE STRONG FORCING WILL LIKELY RESULT
IN SHORT LINE SEGMENTS WITH LARGE HAIL AND DAMAGING WINDS THE
PRIMARY THREAT AS THE STORMS MOVE INTO ERN KS AND NERN OK BY FRI
EVE.  THIS ACTIVITY WILL PROBABLY WEAKEN AS IT MOVES INTO MO...BUT
STRONG LLJ AND STRONG MID-LEVEL FLOW MAY MAINTAIN AT LEAST AN ISOLD
SEVERE THREAT OVERNIGHT INTO CNTRL/ERN MO.

FARTHER S...00Z MODELS SUGGEST THAT THE SRN EXTENT OF AFTN TSTM
DEVELOPMENT MAY GROW UPSCALE INTO A SMALL MCS FRI NIGHT FROM SERN OK
AND NERN TX INTO AR.  THIS REGION WILL BE ALONG SRN PERIPHERY OF
STRONGER HEIGHT FALLS AND NRN EDGE OF RETURNING TROPICAL MOISTURE
REGIME.  FORECAST KINEMATIC PROFILES ARE QUITE SUPPORTIVE FOR
SUPERCELLS AND ISOLD TORNADOES COULD OCCUR WITH THE MORE DISCRETE
CELLS ACROSS SERN OK...EXTREME NERN TX AND PARTS OF SWRN AR. 
OTHERWISE...LARGE HAIL AND DAMAGING WINDS WILL BE LIKELY.

..RACY/GRAMS.. 09/21/2006