[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 200109
SWODY1
SPC AC 200108

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0808 PM CDT WED JUL 19 2006

VALID 200100Z - 201200Z

...THERE IS A MDT RISK OF SVR TSTMS OVER A PORTION OF THE UPPER MS
VALLEY...

...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE MIDDLE AND
UPPER MS VALLEY...

...THERE IS A SLGT RISK OF SVR TSTMS OVER WRN LA THROUGH NERN TX...

...IA THROUGH SRN MN AND SRN THROUGH CNTRL WI...

SURFACE OBSERVATIONS SHOW A COLD FRONT FROM A WEAK SURFACE LOW IN
NERN NEB SWWD THROUGH CNTRL AND SWRN NEB. THIS BOUNDARY CONTINUES
NEWD FROM THE LOW THROUGH CNTRL AND NRN MN. FARTHER S AN OUTFLOW
BOUNDARY EXTENDS FROM SRN IL NWWD THROUGH NERN MO INTO W CNTRL AND
NWRN IA WHERE IT INTERSECTS THE FRONT. THE ATMOSPHERE REMAINS
EXTREMELY UNSTABLE IN THE PRE-FRONTAL WARM SECTOR ACROSS MUCH OF IA
WITH MLCAPE FROM 4000 TO 5000 J/KG. WITH THE EXCEPTION OF HIGH BASED
STORMS DEVELOPING WITHIN THE MORE DEEPLY MIXED PLUME JUST AHEAD OF
THE FRONT ACROSS NEB...SURFACE BASED INITIATION HAS YET TO OCCUR.
LACK OF CUMULUS WITHIN THE WARM SECTOR ACROSS IA SUGGESTS THE
BOUNDARY LAYER IS STILL CAPPED AND THIS LENDS UNCERTAINTY AS TO WHEN
THE STRONGER STORMS WILL INITIATE. THE MODERATE RISK THEREFORE
REMAINS CONDITIONAL. SWLY LOW LEVEL JET WILL STRENGTHEN THIS EVENING
OVER THE UPPER MS VALLEY AS NRN STREAM SHORTWAVE TROUGH MOVES ESEWD
THROUGH SRN CANADA AND NRN MN. THIS SUGGEST THAT STORMS WILL
INCREASE N OF THE OUTFLOW BOUNDARY WITHIN ZONE OF ISENTROPIC ASCENT
FROM NRN IA INTO SERN MN AND SRN WI. MANY OF THESE STORMS MAY
INITIALLY BE ELEVATED WITH A THREAT FOR MAINLY LARGE HAIL.
HOWEVER...THE 00Z DAVENPORT RAOB SHOWS THE BOUNDARY LAYER TO BE
SUFFICIENTLY DRY AND WARM TO SUPPORT A THREAT OF DAMAGING
WIND...ESPECIALLY IF STORMS BEGIN TO CONGEAL INTO AN MCS AND IF
STORMS CAN DEVELOP CLOSER TO THE STRONGER SURFACE BASED INSTABILITY
ACROSS IA. GIVEN THE MAGNITUDE OF INSTABILITY AND SUFFICIENT
VERTICAL SHEAR FOR SUPERCELL STRUCTURES...A FEW STORMS COULD PRODUCE
VERY LARGE HAIL...ESPECIALLY IN THE MODERATE RISK AREA. TORNADO
THREAT REMAINS CONDITIONAL UPON BEING ABLE TO INITIATE STORMS CLOSER
TO THE OUTFLOW BOUNDARY ACROSS PARTS OF NRN AND CNTRL IA.


...SRN IL THROUGH E CNTRL AND SERN MO...

THREAT FOR MAINLY DAMAGING WIND IS EXPECTED TO PERSIST FOR ANOTHER
FEW HOURS AS MCS CONTINUES SWD INTO PARTS OF SERN MO. THIS ACTIVITY
IS EXPECTED TO BEGIN AN OVERALL DECREASING TREND AS THE BOUNDARY
LAYER BEGINS TO STABILIZE LATER THIS EVENING.

...LA THROUGH ERN TX...

MCS WILL CONTINUE WSWWD INTO NERN TX NEXT FEW HOURS...BEFORE
BEGINNING AN OVERALL DECREASING TREND LATER THIS EVENING AS THE
BOUNDARY LAYER BEGINS TO STABILIZE. DAMAGING WIND WILL BE THE
PRIMARY THREAT WITH THIS ACTIVITY.

..DIAL.. 07/20/2006