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URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 415

NWS STORM PREDICTION CENTER NORMAN OK

250 PM MDT MON JUL 15 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* TORNADO WATCH FOR PORTIONS OF

  EASTERN MONTANA

  WESTERN AND NORTHERN NORTH DAKOTA



* EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 250 PM UNTIL

  1100 PM MDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL TORNADOES WITH A FEW INTENSE TORNADOES POSSIBLE

  SEVERAL VERY LARGE HAIL EVENTS TO 4 INCHES IN DIAMETER POSSIBLE

  SEVERAL DAMAGING WIND GUSTS WITH A FEW SIGNIFICANT GUSTS TO 75

    MPH POSSIBLE



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 100 STATUTE

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

WILLISTON NORTH DAKOTA TO 50 MILES SOUTH SOUTHEAST OF BAKER

MONTANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU5).



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...SFC-BASED TSTMS EXPECTED TO FORM IN THE NEXT HOUR OR SO

ALONG LEE TROUGH IN ERN MT...AND POSSIBLY ALONG COLD FRONT IN THE NE

PART OF THE STATE. DEVELOPMENT WILL BE FOSTERED BY CONTINUED SFC

HEATING...LOW-LVL MOISTURE INFLOW...ASCENT ASSOCIATED BOTH MAIN UPR

IMPULSE MOVING ENE FROM SRN AB...AND BY UPLIFT WITH WEAKER

DISTURBANCE MOVING ENE FROM SW MT/NW WY.

DEEP EML ATOP FAIRLY RICH LOW-LVL MOISTURE /PW AROUND 1 INCH/ IN

MODERATELY TO STRONGLY SHEARED ENVIRONMENT COULD YIELD STORMS WITH

VERY LARGE HAIL AND BOWING SEGMENTS WITH HIGH WIND. SOME RISK ALSO

WILL EXIST FOR TORNADOES...ESPECIALLY IN NERN MT AND NW ND...WHERE

LOW-LVL WINDS ARE LIKELY TO REMAIN SOMEWHAT BACKED...TEMP-DEW POINT

SPREADS WILL BE SMALLEST...AND DEEP SHEAR GREATEST. ACTIVITY MAY

EVOLVE INTO A SQLN WITH EMBEDDED LEWPS CONTINUING A RISK FOR SVR

WIND/HAIL AND ISOLD TORNADOES FARTHER E INTO ND TNGT.



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

SURFACE AND ALOFT TO 4 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 65 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

550. MEAN STORM MOTION VECTOR 26020.





...CORFIDI

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