SPC MESOSCALE DISCUSSION 0739 FOR NERN WI...U.P. OF MI/WRN LOWER MI
CONCERNING...SEVERE THUNDERSTORM POTENTIAL...

VALID 150325Z - 150500Z

THUNDERSTORMS SHOULD CONTINUE TO DEVELOP OVER EXTREME NERN WI AND
THE U.P. OF MI...WITH SEWD MOVEMENT EXPECTED INTO WRN LOWER MI. 
SHEAR PROFILES FAVOR STORM ROTATION...HOWEVER ACTIVITY WILL REMAIN
ELEVATED AND SEVERE THREAT WILL BE LIMITED TO LARGE HAIL.

LLJ IS INCREASING FROM NRN IA INTO CENTRAL WI LATE THIS EVENING AS
LOW LEVEL WARM ADVECTION PATTERN REMAINS FIRMLY ESTABLISHED ACROSS
THE UPPER GREAT LAKES REGION.  INCREASE IN LLJ APPEARS TO BE
NOCTURNAL IN NATURE...BUT LIKELY SUFFICIENT TO MAINTAIN GENERATING
CELLS UPSTREAM OVER NERN WI AND U.P. OF MI.  00Z SOUNDINGS ACROSS
UPPER MS VALLEY REGION INDICATE PRESENCE OF VERY STEEP MID LEVEL
LAPSE RATES...ON THE ORDER OF 8.5 C/KM...AND FAVORABLE WLY
TRAJECTORIES THAT WILL SUPPORT INCREASING MID LEVEL INSTABILITY
ACROSS ERN WI INTO WRN LOWER MI WITH TIME.  MODIFICATION OF GRB
SOUNDING WITH PARCEL LIFT AROUND 850 MB YIELDS CAPE VALUES FROM
1000-1500 J/KG.  STRONG VEERING WITHIN THE CLOUD LAYER SHOULD
SUPPORT STORM ROTATION AND ENHANCE UPDRAFT STRENGTH AND HAIL
POTENTIAL.  WITH ACTIVITY EXPECTED TO CONTINUE DEVELOPING OVER NERN
WI...SEWD MOVEMENT WILL CREATING ECHO TRAINING AND THREAT OF HEAVY
RAIN.

..DARROW.. 05/15/01