[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 020535
SWODY1
SPC AC 020533

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1233 AM CDT MON OCT 02 2006

VALID 021200Z - 031200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE UPPER MS
VALLEY/UPPER GREAT LAKES REGION...

...SYNOPSIS...
A SERIES OF WEAK MID-LEVEL SHORT-WAVE TROUGHS ARE FORECAST TO MOVE
EWD ACROSS THE NRN PLAINS INTO THE UPPER MS VALLEY/UPPER GREAT LAKES
...THROUGH LARGE-SCALE MEAN RIDGE.  THIS FLAT RIDGE WILL PREVAIL
ACROSS THE MAJORITY OF THE CONUS THROUGH THE PERIOD...AS ERN TROUGH
MOVES INTO THE N ATLANTIC AND WRN TROUGH REMAINS OVER THE ERN
PACIFIC/WRN CONUS.

AT THE SURFACE...A COLD FRONT IS FORECAST TO MOVE SLOWLY SWD/SEWD
ACROSS THE N CENTRAL CONUS WHILE BECOMING ORIENTED INCREASINGLY E-W
WITH TIME...AS EWD-SURGE OF FRONT IS FORECAST FURTHER N ACROSS
ONTARIO.  MEANWHILE...A WEAK LOW IS FORECAST TO MOVE ENEWD ALONG
THIS FRONT INTO THE MID MO VALLEY REGION DURING THE LATTER HALF OF
THE PERIOD.

...UPPER MS VALLEY/UPPER GREAT LAKES REGION...
THUNDERSTORMS WILL LIKELY BE ONGOING AT THE START OF THE PERIOD
ACROSS PARTS OF THE UPPER GREAT LAKES REGION...IN ZONE OF WARM
ADVECTION NEAR THE NOSE OF A VEERING LOW-LEVEL JET.

AS THIS CONVECTION SHIFTS EWD/SEWD WITH TIME INTO LOWER
MI/IN...DESTABILIZATION SHOULD OCCUR OVER THE UPPER MS VALLEY AS
LOW-LEVEL MOISTURE ADVECTS NWD INTO THIS REGION AHEAD OF COLD
FRONT...AND BENEATH ELEVATED MIXED LAYER.  PRESUMING SOME HEATING
CAN OCCUR IN THE WAKE OF INITIAL CONVECTION...MODERATE AIRMASS
DESTABILIZATION SHOULD OCCUR -- THOUGH BOUNDARY LAYER WILL LIKELY
REMAIN CAPPED WELL INTO THE AFTERNOON.

AS COLD FRONT MOVES SEWD INTO THIS REGION DURING THE
AFTERNOON/EVENING...SCATTERED CONVECTIVE DEVELOPMENT IS FORECAST. 
STORMS ARE EXPECTED TO CONTINUE/SPREAD EWD INTO THE OVERNIGHT
HOURS...AS SURFACE LOW SHIFTS EWD TOWARD THE REGION IN CONJUNCTION
WITH AN UPPER IMPULSE MOVING EWD ACROSS THE PLAINS DURING THE LATTER
HALF OF THE PERIOD.

DEEP-LAYER SHEAR IS FORECAST TO REMAIN GENERALLY MARGINAL FOR
WELL-ORGANIZED STORMS...WITH FASTER WLY FLOW ALOFT REMAINING N OF
THE U.S./CANADA BORDER.  HOWEVER...GIVEN DEGREE OF INSTABILITY WHICH
WILL LIKELY EVOLVE...A FEW STRONGER MULTICELL CLUSTERS AND PERHAPS A
COUPLE SUPERCELL STORMS WILL BE POSSIBLE.  MAIN SEVERE THREAT SHOULD
BE HAIL...THOUGH LOCALLY-DAMAGING WINDS WILL ALSO BE POSSIBLE --
MAINLY DURING THE AFTERNOON AND EARLY EVENING.

..GOSS.. 10/02/2006