[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 170055
SWODY1
SPC AC 170053

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0753 PM CDT SUN JUL 16 2006

VALID 170100Z - 171200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF ERN SD EWD
TO THE UPPER GRTLKS...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE DESERT
SW...

...ERN SD EWD TO THE UPPER GRTLKS...
LATEST SFC MESOANALYSIS PLACES A WEAK TROUGH FROM NEAR LAKE OF THE
WOODS SWWD INTO CNTRL SD...ASSOCIATED WITH A SUBTROPICAL IMPULSE
MIGRATING EWD THROUGH SD.  A STRONGER NRN STREAM IMPULSE WAS DIGGING
SEWD THROUGH THE CANADIAN PRAIRIES WITH A MORE SIGNIFICANT COLD
FRONT ARCING FROM LAKE WINNIPEG SWWD INTO NCNTRL MT.

HIGH-BASED TSTMS ROOTED INTO THE VERY UNSTABLE BOUNDARY LAYER ACROSS
THE MN ARROWHEAD EARLY THIS EVE...PRESUMABLY WHERE LOW-LEVEL WARM
ADVECTION WAS MAXIMIZED JUST NE OF THE PRIMARY THERMAL RIDGE OVER
THE PLAINS.  THESE TSTMS HAVE WEAKENED...BUT NEW STORMS MAY FORM
OVERNIGHT...BOTH ALONG THE LLJ AXIS FROM LK SUP EWD INTO UPPER
MI...NWRN-SRN ONT...AND AHEAD OF THE NRN STREAM JETLET ACROSS NRN
MN.  SUFFICIENT EFFECTIVE SHEAR WILL EXIST FOR SUPERCELLS...WITH
LARGE HAIL AND DAMAGING WINDS POSSIBLE.

A SECONDARY AREA OF TSTM DEVELOPMENT APPEARS PROBABLE ACROSS EXTREME
ERN SD EWD INTO CNTRL/SRN MN THIS EVE AHEAD OF THE SUBTROPICAL
DISTURBANCE.  THESE STORMS...INITIALLY HIGH-BASED...COULD TAP INTO
MORE UNSTABLE PARCELS EMANATING FROM THE HIGHER THETA-E AXIS ACROSS
THE CORN BELT. IF THIS OCCURS...WHETHER STORMS REMAIN ELEVATED OR
BECOME SFC BASED...LARGE HAIL AND/OR DAMAGING WINDS WILL BE RISKS. 
THESE STORMS COULD MOVE INTO PARTS OF THE UPPER MS VLY REGION BY 12Z
MON.

...DESERT SW...
ENHANCED LOW/MID-TROPOSPHERIC ELY FLOW DOMINATED THE DIURNAL CYCLE
AGAIN OVER SERN AZ...CONTRIBUTING TO DOWNSLOPE AND SUBSEQUENT DRYING
OF THE BOUNDARY LAYER...LIMITING INSTABILITY.  FARTHER NW...TSTMS
HAVE BEEN WIDELY SCATTERED AND FAVORING AREAS THAT DID NOT SEE
ROBUST CONVECTION YESTERDAY.  MOST UNSTABLE AIR MASS THIS EVENING
REMAINS OVER THE LOWER DESERTS FROM WRN PIMA COUNTY NWD TO MOHAVE
COUNTY.  TSTMS THAT DEVELOP/MOVE WITHIN/INTO THIS INSTABILITY AXIS
WILL BE CAPABLE OF PRODUCING DAMAGING WIND GUSTS/HAIL. 
BUT...OVERALL...THE SEVERE THREATS SEEM TO BE LOWER THAN PREVIOUSLY
ANTICIPATED.

..RACY.. 07/17/2006