[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 251955
SWODY1
SPC AC 251954

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0254 PM CDT TUE JUL 25 2006

VALID 252000Z - 261200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE UPPER
MIDWEST....

...SYNOPSIS...
LATEST WATER VAPOR IMAGERY DEPICTS VERY WELL MID/UPPER LEVEL
SHORTWAVE TROUGH MOVING SEWD ACROSS MANITOBA AND SERN SASKATCHEWAN. 
THIS WILL CONTINUE TO MOVE SEWD THE REMAINDER OF THE PERIOD AS
STRONG MID/UPPER LEVEL RIDGE COVERS THE SWRN QUARTER OF THE U.S.  IN
ADDITION...MID/UPPER LEVEL TROUGH WILL CONTINUE TO MOVE NWD FROM THE
NERN MEXICAN COAST INTO THE MIDDLE TX COAST REGION.

...UPPER MIDWEST...

LATEST SURFACE ANALYSIS SHOWS WEAK COLD FRONTAL BOUNDARY EXTENDING
FROM EXTREME NWRN MN TO A LOW OVER THE CENTRAL ND/SD BORDER...THEN
NWWD THRU SERN AND N CENTRAL MT.  THIS IS DEVELOPING INTO SOMEWHAT
OF A COMPLEX SITUATION AS THERE HAVE BEEN SHOWERS/ISOLATED
THUNDERSTORMS OVER PARTS OF THE MIDDLE MO VALLEY THUS FAR AND
CONVECTION HAS FIRED ALONG THE FRONTAL BOUNDARY OVER NWRN MN INTO
EAST CENTRAL ND.  THIS ACTIVITY WILL BE MOVING INTO AN AXIS WITH
VERY UNSTABLE AIR WHERE MLCAPES RANGE BETWEEN 2000 AND 2500 J/KG
FROM NERN SD SEWD INTO SWRN WI AND NRN IL.

IT LOOKS LIKE THERE ARE TWO SITUATIONS WHERE SEVERE WEATHER CAN
DEVELOP THRU EARLY TONIGHT ACROSS THE UPPER MIDWEST.  FIRST...EXPECT
FRONTAL BOUNDARY DEVELOPMENT TO CONTINUE AND INTENSIFY AS IT MOVES
SEWD FEEDING ON THE THERMODYNAMICS FROM SD INTO IL.  SECOND WILL BE
THE BOUNDARIES IN THE VICINITY OF ELEVATED CONVECTION OVER SERN
SD/ERN NEB/WRN IA.  STORMS COULD REINTENSIFY OVER IA WHERE MLCAPE
HAS REACHED 3000 J/KG ALLOWING BOUNDARIES TO BE PRESENT AHEAD OF
APPROACHING COLD FRONT LATER THIS EVENING AND TONIGHT.

THUS...WITH BOTH SCENARIOS LOOKS LIKE MAIN THREAT WILL BE STRONG
DAMAGING WINDS AND SOME HAIL ACROSS THE REGION.

...LOWER GREAT LAKES...

LAKE BREEZE THUNDERSTORMS HAVE DEVELOPED FROM SWRN NY STATE SWWD
INTO NERN OH.  ACTIVITY IS WITHIN AREA WHERE MLCAPES ARE AROUND 1000
J/KG AHEAD OF WEAK VORTICITY MAX MOVING EWD OVER EXTREME SERN
ONTARIO JUST ALONG THE NERN SHORES OF LAKE ERIE.  MID LEVEL LAPSE
RATES ARE AROUND 7C/KM WHICH WOULD BE SUPPORTIVE OF GUSTY WINDS WITH
THUNDERSTORM ACTIVITY. WOULD ANTICIPATE MORE SCATTERED STRONG
THUNDERSTORMS TO DEVELOP IN CU FIELD THAT IS EXTENDING NEWD TOWARDS
NRN VERMONT AGAIN WITH THE THREAT BEING MAINLY GUSTY WINDS.

...PARTS OF THE DESERT SOUTHWEST...

SEE MESOSCALE DISCUSSION 1624 FOR THE LATEST INFORMATION ON SEVERE
THUNDERSTORM POTENTIAL.

..MCCARTHY.. 07/25/2006