TORNADO WATCH NUMBER 355

URGENT - IMMEDIATE BROADCAST REQUESTED
   TORNADO WATCH NUMBER 355
   NWS STORM PREDICTION CENTER NORMAN OK
   550 PM MDT MON JUN 4 2012
   
   THE NWS STORM PREDICTION CENTER HAS ISSUED A
   TORNADO WATCH FOR PORTIONS OF 
   
          NORTH CENTRAL MONTANA
   
   EFFECTIVE THIS MONDAY AFTERNOON AND TUESDAY MORNING FROM 550 PM
   UNTIL 100 AM MDT.
   
   TORNADOES...HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND
   GUSTS TO 75 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
   AREAS.
   
   THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 110 STATUTE
   MILES EAST AND WEST OF A LINE FROM 45 MILES NORTHWEST OF HAVRE
   MONTANA TO 55 MILES SOUTH OF GREAT FALLS MONTANA.  FOR A COMPLETE
   DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE
   (WOUS64 KWNS WOU5).
   
   REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
   TORNADOES AND 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.
   
   OTHER WATCH INFORMATION...CONTINUE...WW 352...WW 353...WW 354...
   
   DISCUSSION...SUPERCELLS MENTIONED IN SVR WW 354 ARE EXPECTED TO
   STRENGTHEN AND DEVELOP LWR BASES AS THEY ENCOUNTER INCREASINGLY
   MOIST LOW LVL ESELY FLOW ACROSS N CNTRL MT.  GREAT FALLS MT VWP
   SAMPLES THE 25 KT ELY CURRENT VERY WELL.  WITH THE LOW LVL ELY FLOW
   LIKELY TO STRENGTHEN AS THE CA/ORE UPR TROUGH ASSUMES MORE OF A
   NEGATIVE TILT/ACCELERATES NNEWD...AND AS TEMP-DEW POINT SPREADS
   DECREASE LATER THIS EVE...ENVIRONMENT WILL BECOME MORE FAVORABLE FOR
   LOW LVL MESOCYCLONES/POSSIBLE TORNADOES.  A CONDITIONAL RISK WILL
   EXIST FOR ONE OR TWO STRONG TORNADOES.
   
   AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
   SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE
   WIND GUSTS TO 65 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
   500. MEAN STORM MOTION VECTOR 21035.