[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 221248
SWODY1
SPC AC 221246

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0746 AM CDT FRI SEP 22 2006

VALID 221300Z - 231200Z

...THERE IS A MDT RISK OF SVR TSTMS FROM ERN OK AND MUCH OF AR INTO
PARTS OF MO AND IL...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA
FROM N TX INTO THE OH VLY...

...SYNOPSIS...
UNSEASONABLY STRONG CLOSED LOW NOW NEARING FSD EXPECTED TO DRIFT N
OR NNW THROUGH THE PERIOD AS UPSTREAM DISTURBANCE IN BROAD CYCLONIC
FLOW MOVES FROM NRN UT TO ERN CO TODAY...AND THEN TURNS E/NE INTO
KS/NEB TONIGHT/EARLY SATURDAY. THIS PATTERN WILL MAINTAIN AND LATER
STRENGTHEN BELT OF FAST WSW FLOW IN PLACE ACROSS THE CENTRAL U.S.

AT LOWER LEVELS...SURFACE LOW IN NW IA SHOULD LIFT SLOWLY N AND
FURTHER OCCLUDE.  ASSOCIATED COLD FRONT WILL CONTINUE SE ACROSS KS
TODAY AND INTO NRN/WRN OK EARLY SATURDAY.  DIFFUSE WARM FRONT NOW
EXTENDING SE ACROSS IA INTO WRN KY SHOULD REDEVELOP N AS NOCTURNAL
BOUNDARY LAYER MIXES OUT AND ELEVATED WARM/MOIST LAYER MIXES
DOWNWARD.  COMPLICATING THE PICTURE WILL BE PRESENCE OF OUTFLOW LEFT
BY OVERNIGHT STORMS IN THE LWR MS VLY/OZARKS.  LOW LEVEL
DESTABILIZATION EXPECTED TO SPREAD MOST RAPIDLY NEWD ALONG WRN SIDE
THE OUTFLOW INTO CNTRL/SRN MO AND WRN IL.

FARTHER W...DRY LINE NOW EXTENDING FROM CNTRL MO THROUGH NE OK TO
CNTRL TX MAY MIX SLIGHTLY E TODAY BEFORE BECOMING STATIONARY AND
RETROGRESSING WWD TONIGHT AS UT/CO IMPULSE CONTINUES E...AND
ASSOCIATED SURFACE WAVE STRENGTHENS OVER THE TX PANHANDLE.


...ERN OK/OZARKS INTO MID MS VLY...
...SIGNIFICANT SEVERE THREAT EXPECTED TODAY THROUGH EARLY
SATURDAY...
PERSISTENT AREA OF OVERNIGHT STORMS LIKELY WILL DELAY LOW LEVEL
DESTABILIZATION OVER PARTS OF THE LWR TN...LWR OH AND MID MS VLYS
TODAY AS ASSOCIATED VORT LOBE NOW ROUNDING SE QUADRANT OF SD UPR LOW
CONTINUES NEWD.

REGIONAL VWP/PROFILER DATA...AND SATELLITE/GPS MOISTURE DATA
NEVERTHELESS INDICATE THAT SUBSTANTIAL MOISTENING HAS OCCURRED
OVERNIGHT IN THE 925-850 MB LAYER OVER AR/WRN TN AND PARTS OF MO IN
RESPONSE TO PERSISTENT 40+ KT SWLY LLJ.  THIS MOISTURE LIKELY WILL
CONTINUE TO SPREAD NEWD THROUGH THE PERIOD...AND SHOULD MIX TO THE
SURFACE BY THIS AFTERNOON ACROSS THE SE HALF OF MO AND CNTRL/SRN IL.
BY TONIGHT AND EARLY SATURDAY...EXPECT THAT LOW LEVEL MOISTURE WILL
ALSO SPREAD NE INTO ERN OK AS NEW LLJ DEVELOPS DOWNSTREAM FROM
APPROACHING UT/CO DISTURBANCE.

COMBINATION OF MODERATE TO STRONG HEATING ON WRN/SRN EDGE OF
CONVECTIVE OUTFLOW/DEBRIS...AND CONVERGENCE ALONG ASSOCIATED OUTFLOW
BOUNDARIES/DRY LINE...LIKELY TO RESULT IN SUFFICIENT
DESTABILIZATION/LIFT TO SUPPORT STORM DEVELOPMENT IN WEAKLY CAPPED
ENVIRONMENT BY EARLY TO MID AFTERNOON FROM ERN OK/WRN AR NEWD INTO
MO/IL. WHILE SOME MID LEVEL WARMING MAY OCCUR IN WAKE OF
AFOREMENTIONED VORT LOBE...MLCAPE SHOULD REACH 1500-2000 J/KG OVER
AR AND SRN MO...AND 1000 TO PERHAPS 1500 J/KG ACROSS THE REMAINDER
OF MO INTO CENTRAL IL.

OVERALL SETUP WITH INCREASINGLY BROAD...MOIST...AND WEAKLY
CONVERGENT WARM SECTOR SURMOUNTED BY STRONG SWLY MID LEVEL FLOW
SUGGESTS PROBABLE DEVELOPMENT OF MULTIPLE BANDS OF STORMS.  LONG
HODOGRAPHS WITH SUBSTANTIAL LOW LEVEL VEERING /40+ KT SSWLY LOW
LEVEL JET BENEATH 50-70 KT WSWLY MID LEVEL FLOW/ SHOULD SUPPORT
SCATTERED PERSISTENT SUPERCELLS WITH STRONG LOW LEVEL ROTATION. 
COUPLED WITH LOW LCL HEIGHTS AND BETTER THAN AVERAGE LIKELIHOOD FOR
DISCRETE STORMS AND/OR EMBEDDED SUPERCELLS WITHIN SHORT LINE
SEGMENTS...A THREAT WILL EXIST FOR A FEW STRONG AND POSSIBLY
LONG-TRACKED TORNADOES.  OTHER ACTIVITY MAY YIELD LOCALLY DAMAGING
WIND AND...MAINLY IN THE WRN HALF OF THE MODERATE RISK AREA...SEVERE
HAIL.

THE STORMS SHOULD SPREAD NE THROUGH THE EVENING ACROSS THE MID MS
AND LWR OH VLYS.  OTHER SEVERE STORMS MAY FORM LATER TONIGHT THROUGH
EARLY SATURDAY INVOF RETROGRESSING DRY LINE AND ACCELERATING COLD
FRONT IN SE KS/ERN OK AND PERHAPS N TX.  THESE STORMS MAY REMAIN
SEVERE AS THEY MOVE/DEVELOP NE INTO PARTS OF MO AND WRN AR SATURDAY
MORNING.

..CORFIDI/GRAMS.. 09/22/2006