[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 260531
SWODY1
SPC AC 260530

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1130 PM CST SAT NOV 25 2006

VALID 261200Z - 271200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
LARGE SCALE UPPER TROUGH LOCATED WEST OF THE ROCKIES IS EXPECTED TO
AMPLIFY THIS FORECAST PERIOD AS VORTEX OVER BRITISH COLUMBIA MOVES
SWD TOWARD PACIFIC NW AND DEEPENS.  AS THIS PROCESS OCCURS...PACIFIC
SHORT WAVE TROUGH...CURRENTLY LOCATED NEAR 49N 139W PER WATER VAPOR
IMAGERY...WILL DIG SSEWD REACHING SRN CA/GREAT BASIN BY 12Z MONDAY.
DOWNSTREAM SHORT WAVE TROUGH TRACKING NEWD FROM FOUR CORNERS REGION
TO THE CENTRAL PLAINS AND MID MO VALLEY WILL LIKELY DE-AMPLIFY AS IT
APPROACHES REGION OF HEIGHT RISES/RIDGING ACROSS THE CENTRAL STATES.

...PACIFIC NW COAST SWD ALONG THE NRN CA COAST...
STRONG HEIGHT FALLS ARE EXPECTED ACROSS THIS REGION AS UPPER VORTEX
DEEPENS DURING THE FORECAST PERIOD.  INITIAL THREAT FOR TSTMS SHOULD
BE AS ASCENT ASSOCIATED WITH PACIFIC SHORT WAVE TROUGH/SURFACE FRONT
SPREADS INLAND ALONG THE ORE TO NRN CA COAST THIS MORNING AND
AFTERNOON.  ADDITIONAL TSTMS WILL BE LIKELY OFFSHORE TO ALONG THE
PAC NW COAST BY THIS EVENING WITHIN MOIST...POST-FRONTAL ONSHORE
FLOW REGIME LOCATED BENEATH VERY COLD MID LEVEL TEMPERATURES /-30 TO
-34 C AT 500 MB/.

...IA/FAR SRN MN/SWRN WI SWWD TO ERN NEB/NERN KS...
IN THE LOW LEVELS...SURFACE BOUNDARY EXPECTED TO EXTEND FROM NRN KS
ENEWD INTO SRN IA AND SRN WI SHOULD REMAIN NEARLY STATIONARY
TODAY...AS A COLD FRONT...INITIALLY EXTENDING FROM NRN NEB TO NRN
WI...MOVES SWD MERGING WITH THE SRN BOUNDARY.  LOW LEVEL MOISTURE
WILL CONTINUE TO SPREAD NNEWD WITH SURFACE DEWPOINTS IN THE LOWER
50S REACHING SERN NEB TO SRN IA/SRN WI BY LATE THIS AFTERNOON.

ALTHOUGH THE FOUR CORNERS TROUGH WILL BE DE-AMPLIFYING AS IT
APPROACHES THE CENTRAL PLAINS TO MID MO VALLEY TONIGHT...PLUME OF
STEEP MID LEVEL LAPSE RATES /7+ C/KM/ WILL BE ADVECTED DOWNSTREAM
AHEAD OF THIS TROUGH AND ATOP NRN EXTENT OF MOISTURE RETURN.  THIS
WILL AID IN WEAK DESTABILIZATION.  DESPITE WEAK UPPER FORCING THIS
EVENING AND OVERNIGHT WITH THE DAMPENING TROUGH...INCREASING LOW
LEVEL WAA SHOULD SUPPORT AN AREA OF TSTMS FROM ERN NEB/NERN KS
ACROSS IA/FAR SRN MN AND POTENTIALLY SWRN WI.  SMALL HAIL COULD
ACCOMPANY THE STRONGER STORMS...THOUGH THE MARGINAL INSTABILITY
SHOULD PRECLUDE ANY SEVERE THREAT.

..PETERS/TAYLOR.. 11/26/2006