WWUS20 KWNS 072203
SEL6
SPC WW 072203
IDZ000-MTZ000-WYZ000-080500-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 396
NWS STORM PREDICTION CENTER NORMAN OK
400 PM MDT SUN JUL 7 2013

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF 
  PARTS OF EASTERN IDAHO
  MUCH OF CENTRAL AND SOUTHERN MONTANA
  NORTHERN WYOMING

* EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 400 PM UNTIL
  1100 PM MDT.

* PRIMARY THREATS INCLUDE...
  SEVERAL LARGE HAIL EVENTS WITH A FEW VERY LARGE HAIL EVENTS TO 2
    INCHES IN DIAMETER POSSIBLE
  SEVERAL DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 115
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 40 MILES SOUTH OF
HELENA MONTANA TO 65 MILES EAST SOUTHEAST OF BROADUS MONTANA. 
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU6).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 394...WW 395...

DISCUSSION...STORMS CONTINUE TO DEVELOP AND MOVE EWD THIS AFTERNOON
ACROSS THE EASTERN IDAHO/MONTANA/WYOMING VICINITY...AHEAD OF A WEAK
MID-LEVEL SHORT-WAVE TROUGH MOVING ACROSS THE AREA.  WITH AMPLE
INSTABILITY DEVELOPING THROUGH THE PEAK HEATING HOURS AND MODERATE
ENELY MID-LEVEL FLOW YIELDING DEEP-LAYER SHEAR SUFFICIENT FOR AT
LEAST ISOLATED SEVERE STORMS...EXPECT LOCALLY DAMAGING WINDS AND
LARGE HAIL WITH STRONGER CELLS AS CONVECTION SHIFTS EWD TOWARD THE
NRN HIGH PLAINS THROUGH THE EVENING HOURS.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 26035.


...GOSS