[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 240059
SWODY1
SPC AC 240057

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0757 PM CDT TUE MAY 23 2006

VALID 240100Z - 241200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF NRN/CENTRAL
PLAINS EWD INTO WRN MN/WRN-CENTRAL IA AND NWRN MO...

...NRN/CENTRAL PLAINS INTO NWRN MO/WRN-CENTRAL IA/SWRN MN...
UPPER TROUGH...CURRENTLY LOCATED OVER THE WRN DAKOTAS...WILL BEGIN
TO MAKE A MORE EWD MOVEMENT ACROSS ND/SD THE REST OF THIS FORECAST
PERIOD.  BAND OF 50 KT SWLY MID LEVEL WINDS ACCOMPANYING THIS STORM
SYSTEM AND NOW EXTENDING FROM WRN KS ACROSS NEB TO ERN SD WILL
CONTINUE TO TRANSLATE EWD ATOP SOMEWHAT NARROW/MOIST WARM SECTOR
OVER THE ERN PLAINS TO WRN MN/WRN IA/WRN MO.  THIS MID LEVEL FLOW
COMBINED WITH STRENGTHENING NOCTURNAL SLY LLJ TO 50 KT FROM ERN KS
TO ERN NEB/WRN IA WILL RESULT IN INCREASING DEEP LAYER SHEAR FOR
CONTINUATION OF ORGANIZED STORMS ALONG COLD FRONT ADVANCING EWD
THROUGH SD/NEB/KS OVERNIGHT.  SHEAR VECTORS ORIENTED PARALLEL TO
MUCH OF THE ONGOING LINE OF STORMS FROM ERN SD SWD INTO ERN NEB
EXPECTED TO MAINTAIN LINEAR CONVECTIVE MODE WITH DAMAGING WINDS AND
HAIL THE PRIMARY THREATS...THOUGH EMBEDDED SUPERCELLS WILL BE
POSSIBLE.  TORNADO POTENTIAL...EXPECTED MAINLY DURING THIS
EVENING...SHOULD EXTEND FROM PARTS OF ERN NEB INTO WRN IA AND SWD
INTO NERN KS WHERE LOW LEVEL DIRECTIONAL SHEAR WILL BE GREATEST
ALONG INCREASING LLJ AND BENEATH SWLY FLOW ALOFT.  ALSO...DEEP LAYER
SHEAR INCREASING IN MAGNITUDE IS EXPECTED TO REMAIN MORE NORMAL TO
THE COLD FRONT/PRE-FRONTAL DRY LINE FAVORING ADDITIONAL THREAT FOR
DISCRETE STORMS.

LLJ WILL BE MAINTAINED AND SHOULD VEER TO SWLY OVERNIGHT IN RESPONSE
TO 60-90 METER 500 MB HEIGHT FALLS SPREADING EWD TOWARD THE UPPER MS
VALLEY AHEAD OF THE UPPER TROUGH.  PRIND SUGGEST UPSCALE GROWTH OF
ONGOING ACTIVITY INTO AN MCS WITH STRONG WIND GUSTS AND HAIL
BECOMING THE PRIMARY THREAT...WITH ACTIVITY POTENTIALLY TURNING
TOWARD THE SE ACROSS IA INTO NRN MO/ERN KS.

...NWRN MN WWD THROUGH ND TO NERN MT...
AIR MASS IS MODERATELY UNSTABLE ACROSS NWRN MN WWD THROUGH NRN ND
INTO NERN MT.  ASCENT AHEAD OF THE UPPER TROUGH IS EXPECTED TO
SUPPORT ADDITIONAL THUNDERSTORMS THROUGH THE EVENING/OVERNIGHT
ACROSS MAINLY ND INTO NWRN MN...WITH A DECREASING TREND OVER ERN MT.
 ONGOING STORMS OVER PARTS OF WEST CENTRAL MN/SERN ND AND MORE
RECENT STORMS WWD ALONG VICINITY OF ND/SD BORDER WILL CONTINUE TO
TRACK NNEWD INTO THE INSTABILITY AXIS SUPPORTING SOME THREAT FOR
HAIL AND STRONG WIND GUSTS.

...NERN ORE/ERN WA/NRN ID...
ASCENT AHEAD OF A SHORT WAVE TROUGH MOVING NNEWD ACROSS ORE/WA AT
THIS TIME WILL AID IN ADDITIONAL THUNDERSTORM DEVELOPMENT THIS
EVENING.  STEEP LAPSE RATES...MARGINAL INSTABILITY AND 25-30 KT OF
DEEP LAYER SHEAR PER 00Z RAOB AT SPOKANE SUGGESTS A CONTINUED
POTENTIAL FOR AN ISOLATED SEVERE THREAT OF HAIL/STRONG WIND GUSTS.

..PETERS.. 05/24/2006