[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 212005
SWODY1
SPC AC 212003

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0303 PM CDT WED JUN 21 2006

VALID 212000Z - 221200Z

...THERE IS A MDT RISK OF SVR TSTMS FROM NRN IL TO WRN LAKE ERIE...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM
THE EAST SLOPES OF THE CNTRL/SRN ROCKIES TO WRN NY...

...NRN IL TO LAKE ERIE...

MOST NOTABLE CHANGE OVER THE LAST FEW HOURS ACROSS THE MDT RISK AREA
 IS THE RAPID DESTABILIZATION FROM IND INTO WRN OH/SRN LOWER MI. 
THIS AIRMASS RECOVERY IS THE RESULT OF NW-SE ORIENTED WARM FRONT
GRADUALLY RETREATING AHEAD OF SHORTWAVE TROUGH.  SATELLITE IMAGERY
SUGGESTS CU FIELD IS EXPANDING/DEEPENING ALONG THE IND/OH BORDER
INTO SRN LOWER MI WHICH SHOULD EVOLVE INTO THUNDERSTORM ACTIVITY AS
LOW LEVEL CONVERGENCE REMAINS SUSTAINED IN THIS REGION.  SHEAR
PROFILES ARE STRONG...WITH SFC-6KM VALUES IN EXCESS OF 50-60KT. 
DISCRETE SUPERCELLS MAY INITIATE OVER THE NEXT 1-2 HOURS WHERE
EXTREME INSTABILITY IS PRESSING EWD ALONG ZONE OF SUSTAINED WARM
ADVECTION.  IF DISCRETE STORMS CAN INDEED DEVELOP...TORNADOES ARE
CERTAINLY A POSSIBILITY PRIOR TO MORE ORGANIZED MCS ACTIVITY LATER
TONIGHT.  ADDITIONALLY...VERY LARGE HAIL MAY ALSO OCCUR.

UPSTREAM...WEAK MVC REMAINS EVIDENT IN SATELLITE IMAGERY OVER NERN
IA.  THUNDERSTORMS ARE GRADUALLY ORGANIZING ALONG WIND SHIFT
ASSOCIATED WITH THIS FEATURE...TRAILING SWWD TO NEAR THE MO BORDER. 
DEEP WSWLY FLOW HAS SLOWED THE UPWARD GROWTH OF THIS ACTIVITY...BUT
WITH TIME A FORWARD PROPAGATING MCS...AND POSSIBLE DERECHO MAY
EVOLVE AS CONVECTION SPREADS EWD ACROSS NRN IL TOWARD NRN IND/SRN
LOWER MI LATER TONIGHT.  DAMAGING WINDS ARE THE PRIMARY SEVERE
THREAT IF THIS EVOLUTION OCCURS.

...CENTRAL/SRN HIGH PLAINS...

THUNDERSTORMS ARE GRADUALLY INCREASING IN INTENSITY ALONG THE
CNTRL/SRN FRONT RANGE OF CO AS NELY BOUNDARY LAYER FLOW INCREASES. 
THIS ACTIVITY WILL SPREAD ACROSS THE LOWER ELEVATIONS WHERE
MOISTENING CONTINUES...AND LLJ SHOULD INCREASE LATER TONIGHT.  IT
APPEARS MULTIPLE SUPERCELL CLUSTERS/MERGERS WILL EVOLVE OVER ERN
CO/WRN KS LATER TONIGHT.  ADDITIONALLY...VEERED LEE TROUGH/DRY LINE
ORIENTATION FROM THE WRN TX PANHANDLE...NEWD INTO THE ERN OK
PANHANDLE WILL BECOME A FOCUS FOR POTENTIAL SEVERE THUNDERSTORM
DEVELOPMENT LATER THIS AFTERNOON.  VERY WARM TEMPERATURES HAVE
DEVELOPED ALONG THIS TROUGH WITH READINGS NOW APPROACHING 100F. 
THUNDERSTORMS WILL INITIALLY BE HIGH BASED BUT MAY ROOT INTO MOIST
BOUNDARY LAYER IN PLACE JUST EAST OF THE DRY LINE...IF SO VERY LARGE
HAIL COULD ACCOMPANY THE OTHERWISE GUSTY DOWNDRAFT ENVIRONMENT IN
PLACE.

..DARROW.. 06/21/2006