SPC MESOSCALE DISCUSSION 1481 FOR THE NRN HIGH PLAINS
CONCERNING...SEVERE THUNDERSTORM POTENTIAL...

VALID 112013Z - 112200Z

THUNDERSTORMS WILL CONTINUE TO INCREASE OVER ERN MT/NERN WY DURING
THE NEXT 1-2 HOURS.  THE STRONGER STORMS WILL HAVE A POTENTIAL OF
PRODUCING DAMAGING WINDS/HAIL AND AN ISOLATED TORNADO.  WW MAY BE
NEEDED LATER THIS AFTERNOON.

VISIBLE SATELLITE IMAGERY/SURFACE OBSERVATIONS INDICATE A BOUNDARY
OVER EXTREME ERN MT INTO NERN WY.  TCU/CBS ARE DEVELOPING ALONG
THIS LOW-LEVEL CONVERGENCE ZONE WHERE SUFFICIENT HEATING/MOISTURE
IS RESULTING IN MLCAPE VALUES UP TO 1500 J/KG.  AREA VAD WINDS SHOW
WEAK DEEP LAYER SHEAR AND FLOW OVER THE AREA OF CONCERN...
SUGGESTING STORMS WILL CONTINUE TO INITIATE ALONG THE SURFACE
BOUNDARY.  HOWEVER...LOW-MID LEVEL VEERING WIND PROFILES ALONG AND
EAST OF THE BOUNDARY PER AREA VAD WINDS SHOULD SUPPORT ROTATING
UPDRAFTS.  ANY STORMS THAT ARE ABLE TO MOVE EAST INTO THE
INSTABILITY AXIS COULD BECOME SEVERE WITH THE POTENTIAL FOR
DAMAGING WINDS/LARGE HAIL.  IN ADDITION...A TORNADO OR TWO WILL BE
POSSIBLE GIVEN THE LOW-MID LEVEL VEERING AND BACKED SURFACE WINDS
IN THE VICINITY OF THE BOUNDARY.

..PETERS.. 07/11/01