[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 042000
SWODY1
SPC AC 041959

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0259 PM CDT MON SEP 04 2006

VALID 042000Z - 051200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF NRN IL...

...ERN IA THROUGH NRN IL AND SRN WI...

ZONES OF ASCENT ACCOMPANYING VORTICITY MAXIMA ROTATING THROUGH UPPER
LOW CENTERED OVER ERN IA ARE CONTRIBUTING TO THE DEVELOPMENT OF
SCATTERED THUNDERSTORMS. POCKETS OF SURFACE HEATING BENEATH 500 MB
TEMPERATURES OF -16C TO -18C HAVE RESULTED IN MARGINAL INSTABILITY
WITH MLCAPE  NEAR 500 J/KG. STORMS SHOULD CONTINUE DEVELOPING THE
REMAINDER OF THE AFTERNOON. STRONGEST STORMS ARE EXPECTED OVER NRN
IL INTO EXTREME SRN WI. SURFACE HEATING IS CO-LOCATED WITH SLIGHTLY
HIGHER LOW LEVEL MOISTURE IN THIS REGION...AND ASCENT IS MORE
FOCUSED ON SURFACE BOUNDARY ALONG ERN PERIPHERY OF EWD ADVANCING
VORT MAX. THE THERMODYNAMIC ENVIRONMENT WITH MODERATELY STEEP LAPSE
RATES AND COLD MID LEVEL TEMPERATURES IS SUFFICIENT FOR A THREAT OF
MARGINALLY SEVERE HAIL WITH THE STRONGER STORMS. OVERALL THREAT WILL
REMAIN LIMITED BY MODEST INSTABILITY.

...S CNTRL CO...

MUCH OF THE ASCENT ASSOCIATED WITH A VORT MAX MOVING SWD THROUGH THE
NRN AND CNTRL HIGH PLAINS IS EXPECTED TO REMAIN N OF MOST OF CO THIS
AFTERNOON. IN THE MEANTIME...WV IMAGERY AND FORECAST RUC SOUNDINGS
SUGGEST THE ATMOSPHERE IN CNTRL AND SRN CO IS UNDER THE INFLUENCE OF
LARGE SCALE SUBSIDENCE. THIS ALONG WITH LIMITED INSTABILITY IMPLIES
THUNDERSTORM COVERAGE SHOULD REMAIN SPARSE AT BEST. IF ISOLATED
STORMS DO MANAGE TO DEVELOP...STEEP LAPSE RATES AND DEEP LAYER SHEAR
AROUND 40 KT WOULD SUPPORT A MARGINAL THREAT FOR ISOLATED HAIL.

..DIAL.. 09/04/2006