[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 261639
SWODY1
SPC AC 261637

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1137 AM CDT SAT AUG 26 2006

VALID 261630Z - 271200Z

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTN AND EVENING ACROSS
LOWER MI INTO NERN IL AND NRN IN....

...THERE IS A SLGT RISK OF SVR TSTMS THRU TONIGHT ACROSS PARTS OF
THE CENTRAL PLAINS....

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTN AND EARLY TONIGHT
ACROSS PARTS OF THE CENTRAL ROCKIES....

...SYNOPSIS...
MID/UPPER LEVEL LOW MOVG SEWD INTO THE CENTRAL INTERMOUNTAIN REGION
WILL TURN EWD LATER TODAY AND TONIGHT INTO WY/CO.  MID/UPPER LEVEL
SHORTWAVE TROUGH WILL BE SKIRTING EWD ACROSS ONTARIO AND THE NRN
GREAT LAKES AS MID/UPPER LEVEL RIDGING REMAINS OVER THE SERN QUARTER
OF THE U.S.

MORNING SURFACE ANALYSIS SHOWS WEAKENING LOW PRESSURE OVER SERN WI
WITH A COLD FRONT EXTENDING SWWD INTO NWRN MO...THEN BECOMING
QUASI-STATIONARY ACROSS NERN KS INTO THE TX PANHANDLE. SEVERAL OLD
CONVECTIVE BOUNDARIES ARE DRAPED ACROSS CENTRAL AR...THRU CENTRAL OK
INTO W CENTRAL TX.  ALSO...A WARM FRONT REMAINS FROM THE WI LOW EWD
THRU CENTRAL LOWER MI...THEN IS MORE QUASI-STATIONARY SEWD THRU NWRN
PA AND SRN NJ.

...LOWER MI SSWWD INTO PARTS OF IL AND IN...

SFC LOW OVER SERN WI IS FORECAST TO MOVE NEWD INTO NWRN LOWER MI
THRU LATE THIS AFTERNOON DRAGGING ASSOCIATED COLD FRONT THRU NERN IL
INTO CENTRAL MO.  STRONG THUNDERSTORMS ARE CURRENTLY MOVING ACROSS
NWRN SECTIONS OF LOWER MI IN AREA WITH DEEP LAYER SHEAR AT
APPROXIMATELY 40 KT.  CLOUD COVER IS LIMITING POTENTIAL INSTABILITY
AT THIS TIME WITH MLCAPES BETWEEN 500 AND 1000 J/KG.  PRESENCE OF
SUFFICIENT SHEAR MAY SUPPORT WEAK SUPERCELLS THROUGH THIS REGION
INTO EARLY THIS AFTERNOON.  THERE MAY BE ENOUGH HEATING/LOW LEVEL
WARM ADVECTION LATER OVER E CENTRAL LWR MI THAT MAY ALLOW MORE
THERMODYNAMICS THAT MAY AID IN HAIL AND DAMAGING WINDS.

...PARTS OF THE CENTRAL PLAINS...

AIR MASS ACROSS THIS AREA REMAINS QUITE WARM AND MOIST AS SURFACE
DEW POINTS ARE IN THE UPPER 60S/LOWER 70S.  THE PRESENCE OF OLD
CONVECTIVE OUTFLOWS FROM THE TX PANHANDLE INTO AR MAY A PLAY ROLE TO
ENHANCE LIFT AS DAYTIME HEATING WILL DESTABILIZE THE AIR MASS FOR
MLCAPES TO REACH TO 1500-2000 J/KG.  THE HEATING WILL ALSO STEEPEN
LOW-MID LEVEL LAPSE RATES ACROSS THIS REGION TO BETWEEN 7.0 TO
9.0C/KM.  THUS...WIDELY SCATTERED STRONG/SEVERE THUNDERSTORMS ARE
EXPECTED WITH THE MAIN THREAT BEING STRONG DOWNBURSTS POSSIBLY
ACCOMPANIED BY SOME HAIL.

...INTERMOUNTAIN REGION...

MID/UPPER LEVEL LOW WITH MID LEVEL TEMPERATURES AROUND -14 TO -16C
WILL TRANSLATE ESEWD ACROSS UT INTO WY/CO DURING THE PERIOD.  MOST
NOTABLE IN THE ANALYSIS OF THE LATEST RUC SOUNDINGS IS THE MID LEVEL
DRYING THAT WILL ACCOMPANY THE LOW.  STEEP MID LEVEL LAPSE RATES OF
7-8C/KM WILL BE ACROSS PARTS OF ERN UT INTO WRN CO SUFFICIENT TO
SUPPORT HAIL AND DAMAGING WINDS WITH THUNDERSTORM ACTIVITY THIS
AFTERNOON AND EARLY TONIGHT.

..MCCARTHY/GRAMS.. 08/26/2006