[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 110556
SWODY1
SPC AC 110555

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1255 AM CDT TUE APR 11 2006

VALID 111200Z - 121200Z

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT OVER
THE MID MO VALLEY...

...SYNOPSIS...

SHORT WAVE TROUGH NOW MOVING THROUGH THE LOWER CO VALLEY WILL
CONTINUE NEWD TODAY INTO THE CNTRL PLAINS...AND EVENTUALLY INTO THE
MIDWEST TONIGHT.  IN THE LOW-LEVELS...SURFACE LOW ASSOCIATED WITH
LEAD DISTURBANCE OVER THE DAKOTAS WILL DEVELOP NEWD INTO ONTARIO
WITH SECONDARY CYCLOGENESIS FORECAST ALONG TRAILING COLD FRONT OVER
NRN KS.  THIS SECONDARY LOW WILL THEN RAPIDLY DEVELOP NEWD INTO THE
WRN GREAT LAKES BY WEDNESDAY MORNING.

...MID MO VALLEY...

11/00Z REGIONAL SOUNDINGS INDICATED THAT LOW-LEVEL MOISTURE REMAINS
QUITE LIMITED NWD THROUGH THE GREAT PLAINS WITH THE PRESENCE OF A
WELL DEFINED ELEVATED MIXED LAYER /EML/ AND ASSOCIATED STRONG CAP
OVER THE LOWER PLAINS. PERSISTENT...STRONG SLY LOW-LEVEL FLOW AHEAD
OF THE SECONDARY LOW AND ASSOCIATED FRONT WILL ALLOW FOR SOME
INCREASE IN BOUNDARY-LAYER MOISTURE ACROSS THE SLIGHT RISK AREA WITH
AFTERNOON DEWPOINTS IN THE UPPER 40S TO AROUND 50 F. WHEN COUPLED
WITH DAYTIME HEATING...PRE-FRONTAL AIR MASS IS EXPECTED TO BECOME
WEAKLY TO MODERATELY UNSTABLE WITH SBCAPES OF 500-1000 J/KG.

STRONG CAPPING WILL LIKELY SUPPRESS SURFACE-BASED STORM DEVELOPMENT
ACROSS SLIGHT RISK AREA THROUGH MUCH OF THE AFTERNOON...WITH INITIAL
STORMS FORMING FARTHER TO THE N OVER MN.  HOWEVER...SUSTAINED
LOW-LEVEL CONVERGENCE COMBINED WITH INCREASING HEIGHT FALLS/FORCING
AHEAD OF APPROACHING SHORTWAVE TROUGH SHOULD SUPPORT SWWD
DEVELOPMENT INTO ERN NEB/WRN IA PERHAPS INTO N-CNTRL/NERN KS.

FORECAST SOUNDINGS INDICATE SOME LOW-LEVEL HODOGRAPH CURVATURE WITH
40-50 KTS OF WSWLY MID-LEVEL FLOW WHICH WILL BE SUPPORTIVE OF A FEW
ORGANIZED/ROTATING STORMS.  GIVEN THE PRESENCE OF THE EML AND
RESULTANT STEEP-LAPSE RATES...SEVERE HAIL APPEARS LIKELY WITH THE
STRONGEST STORMS...IN ADDITION TO ISOLATED STRONG WIND GUSTS.

STRENGTHENING LOW-LEVEL WAA SHOULD SUSTAIN STORM CLUSTERS OR A MCS
OVERNIGHT EWD ACROSS IA/SRN MN WITH A CONTINUING POTENTIAL FOR GUSTY
WINDS AND PERHAPS SOME MARGINALLY SEVERE HAIL.

..MEAD/CROSBIE.. 04/11/2006