

379 

WWUS20 KWNS 171833

SEL1

SPC WW 171833

MTZ000-NDZ000-SDZ000-WYZ000-180200-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 311

NWS STORM PREDICTION CENTER NORMAN OK

1235 PM MDT TUE JUN 17 2014



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* TORNADO WATCH FOR PORTIONS OF

  EASTERN MONTANA

  WESTERN NORTH DAKOTA

  WESTERN SOUTH DAKOTA

  NORTHEAST WYOMING



* EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 1235 PM UNTIL

  800 PM MDT.



* PRIMARY THREATS INCLUDE...

  A FEW TORNADOES LIKELY

  SCATTERED LARGE HAIL AND ISOLATED VERY LARGE HAIL EVENTS TO 3

    INCHES IN DIAMETER POSSIBLE

  ISOLATED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE

MILES EAST AND WEST OF A LINE FROM 55 MILES WEST NORTHWEST OF

SIDNEY MONTANA TO 25 MILES EAST SOUTHEAST OF RAPID CITY SOUTH

DAKOTA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



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.



&&



DISCUSSION...A MOIST AND MODERATELY UNSTABLE UPSLOPE FLOW REGIME

WILL ALIGN WITH STRENGTHENING DEEP-LAYER SHEAR TO SUPPORT AN

ENVIRONMENT VERY FAVORABLE FOR SUPERCELLS CAPABLE OF TORNADOES AND

VERY LARGE HAIL THIS AFTERNOON INTO EVENING.



AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

550. MEAN STORM MOTION VECTOR 22020.





...MEAD

