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589 

WWUS20 KWNS 182113

SEL1

SPC WW 182113

MTZ000-190400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 271

NWS STORM PREDICTION CENTER NORMAN OK

315 PM MDT SAT JUN 18 2016



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  CENTRAL AND NORTHEAST MONTANA



* EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 315 PM UNTIL

  1000 PM MDT.



* PRIMARY THREATS INCLUDE...

  SCATTERED DAMAGING WINDS AND ISOLATED SIGNIFICANT GUSTS TO 80

    MPH POSSIBLE

  SCATTERED LARGE HAIL AND ISOLATED VERY LARGE HAIL EVENTS TO 3

    INCHES IN DIAMETER POSSIBLE

  A TORNADO OR TWO POSSIBLE



SUMMARY...SEVERE THUNDERSTORMS WILL CONTINUE TO INCREASE IN COVERAGE

AND INTENSITY AS THEY SPREAD EAST-NORTHEASTWARD ACROSS

CENTRAL/NORTH-CENTRAL MONTANA TOWARD NORTHEAST MONTANA THIS EVENING.

INCREASING LOW-LEVEL MOISTURE...STEEP LAPSE RATES AND A HIGHLY

SHEARED ENVIRONMENT WILL SUPPORT INITIAL SUPERCELLS CAPABLE OF LARGE

HAIL...DAMAGING WINDS...AND POSSIBLY A TORNADO OR TWO. THERE IS SOME

POSSIBILITY THAT PARTS OF NORTHEAST MONTANA COULD WARRANT A TORNADO

WATCH UPGRADE THIS EVENING.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 60

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 45 MILES NORTH OF

GREAT FALLS MONTANA TO 35 MILES NORTH NORTHEAST OF SIDNEY

MONTANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).



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 270...



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 25030.





...GUYER

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