

184 

WWUS20 KWNS 200219

SEL0

SPC WW 200219

MTZ000-201000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 330

NWS STORM PREDICTION CENTER NORMAN OK

820 PM MDT WED JUN 19 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  NORTHEAST MONTANA



* EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 820 PM

  UNTIL 400 AM MDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL DAMAGING WIND GUSTS WITH A FEW SIGNIFICANT GUSTS TO 80

    MPH POSSIBLE

  SEVERAL LARGE HAIL EVENTS WITH A FEW VERY LARGE HAIL EVENTS TO 2

    INCHES IN DIAMETER POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 125

STATUTE MILES EAST AND WEST OF A LINE FROM 60 MILES NORTH

NORTHWEST OF GLASGOW MONTANA TO 90 MILES SOUTH OF GLASGOW

MONTANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).



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 328...



DISCUSSION...POWERFUL MID/UPPER TROUGH AND ASSOCIATED 50-60KT MID

LEVEL JET STREAK WILL EJECT NEWD ACROSS MUCH OF ERN MT THROUGH THE

NIGHT. AS THIS UPPER SYSTEM HAS CONTRIBUTED TO SFC CYCLONE

DEVELOPMENT TO THE LEE OF THE ROCKIES...A WARM AND MOIST AIRMASS HAS

BEEN TRANSPORTED WWD ACROSS MUCH OF ERN MT AHEAD OF THE DEVELOPING

SFC LOW AND WARM FRONT. DEEP-LAYER ASCENT WILL CONTINUE TO ACT ON

THIS AIRMASS TO RESULT IN ROBUST CONVECTION IN THE FORM OF ORGANIZED

CLUSTERS AND LINE SEGMENTS. DEEP SHEAR AND LAPSE RATES WILL BE

SUFFICIENT FOR LARGE HAIL PRODUCTION AS WELL AS HIGH WINDS

ASSOCIATED WITH BOWING SEGMENTS OF CONVECTION SPREADING NEWD THROUGH

LATE TONIGHT.



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

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70

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

MOTION VECTOR 25035.





...CARBIN

