

346 

WWUS20 KWNS 211948

SEL8

SPC WW 211948

NDZ000-220300-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 428

NWS STORM PREDICTION CENTER NORMAN OK

245 PM CDT SUN JUL 21 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* TORNADO WATCH FOR PORTIONS OF

  NORTHERN NORTH DAKOTA



* EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 245 PM UNTIL

  1000 PM CDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL TORNADOES POSSIBLE

  SEVERAL LARGE HAIL EVENTS LIKELY WITH A FEW VERY LARGE HAIL

    EVENTS TO 2 INCHES IN DIAMETER POSSIBLE

  SEVERAL DAMAGING WIND GUSTS TO 70 MPH POSSIBLE



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 100 STATUTE

MILES EAST AND WEST OF A LINE FROM 50 MILES NORTH OF MINOT NORTH

DAKOTA TO 55 MILES SOUTHEAST OF GARRISON NORTH DAKOTA.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU8).



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...FORCING FOR UPWARD VERTICAL MOTION ACCOMPANYING A

VIGOROUS SHORT WAVE IMPULSE...AND ASSOCIATED SURFACE

CYCLONE...PROGRESSING ACROSS SOUTHERN MANITOBA LATE THIS AFTERNOON

AND EVENING IS EXPECTED TO CONTRIBUTE TO STRONG/SEVERE STORM

DEVELOPMENT ACROSS NORTH CENTRAL NORTH DAKOTA.  ACTIVITY IS EXPECTED

TO INITIATE WEST NORTHWEST OF MINOT AFB DURING THE NEXT FEW

HOURS...WITH MORE WIDELY SCATTERED ADDITIONAL DEVELOPMENT CONTINUING

POSSIBLE SOUTHWARD ALONG/AHEAD OF A SURFACE TROUGH AXIS TOWARD THE

BISMARCK AREA.  STORMS...INCLUDING SUPERCELLS...ARE EXPECTED TO THEN

ADVANCE EASTWARD...WITH AN UPSCALE GROWING CONVECTIVE CLUSTER

POSSIBLE FROM NORTH CENTRAL INTO EASTERN NORTH DAKOTA LATER THIS

EVENING.



AVIATION...TORNADOES AND 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 28030.





...KERR

