

744 

WWUS20 KWNS 212301

SEL9

SPC WW 212301

MTZ000-WYZ000-220600-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 189

NWS STORM PREDICTION CENTER NORMAN OK

500 PM MDT SAT MAY 21 2016



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  SOUTHEASTERN MONTANA

  NORTHEASTERN WYOMING



* EFFECTIVE THIS SATURDAY AFTERNOON FROM 500 PM UNTIL MIDNIGHT

  MDT.



* PRIMARY THREATS INCLUDE...

  SCATTERED LARGE HAIL AND ISOLATED VERY LARGE HAIL EVENTS TO 2

    INCHES IN DIAMETER POSSIBLE

  ISOLATED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

  A TORNADO OR TWO POSSIBLE



SUMMARY...THUNDERSTORMS FIRING OFF THE BIGHORN MOUNTAINS ARE

EXPECTED TO SHIFT NORTHWARD TO NORTHEASTWARD ACROSS THE WATCH AREA

THROUGH THIS EVENING...OFFERING MAINLY LARGE HAIL AND DAMAGING

GUSTS.  REFER TO SPC MESOSCALE DISCUSSIONS 667 AND 669 FOR INITIAL

METEOROLOGICAL DETAILS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 40

STATUTE MILES EAST AND WEST OF A LINE FROM 55 MILES SOUTH

SOUTHWEST OF GILLETTE WYOMING TO 25 MILES EAST NORTHEAST OF MILES

CITY MONTANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



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 186...WW 187...WW 188...



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 20035.





...EDWARDS

