

352 

WWUS20 KWNS 212209

SEL7

SPC WW 212209

MNZ000-NDZ000-SDZ000-220400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 427

NWS STORM PREDICTION CENTER NORMAN OK

510 PM CDT MON JUL 21 2014



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  NORTHWEST MINNESOTA

  EASTERN NORTH DAKOTA

  EXTREME NORTH CENTRAL AND NORTHEAST SOUTH DAKOTA



* EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 510 PM UNTIL

  1100 PM CDT.



* PRIMARY THREATS INCLUDE...

  WIDESPREAD DAMAGING WINDS AND ISOLATED SIGNIFICANT GUSTS TO 80

    MPH LIKELY

  SCATTERED LARGE HAIL AND ISOLATED VERY LARGE HAIL EVENTS TO 2

    INCHES IN DIAMETER POSSIBLE

  A TORNADO OR TWO POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 90

STATUTE MILES EAST AND WEST OF A LINE FROM 15 MILES NORTH OF

HALLOCK MINNESOTA TO 90 MILES SOUTH OF JAMESTOWN NORTH DAKOTA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU7).



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 426...



DISCUSSION...MCS DEVELOPMENT IS UNDERWAY JUST W OF BIS AS CELLS

MERGE/GROW UPSCALE AND A COLD POOL EXPANDS.  EXPECT THIS MCS TO

ACCELERATE SOME TO THE E WHILE IT ENCOUNTERS A VERY UNSTABLE

ENVIRONMENT WITH BOTH STRONG UPDRAFT AND DOWNDRAFT POTENTIAL.

THUS...THE POTENTIAL EXISTS FOR WIDESPREAD DAMAGING WINDS...SOME OF

WHICH COULD BE SIGNIFICANT.  OTHERWISE...LARGE HAIL CAN BE EXPECTED

WITH THE STRONGER AND MORE CELLULAR STORMS...WHILE AN ISOLATED

TORNADO CANNOT BE RULED OUT WITH EMBEDDED CIRCULATIONS AND/OR CELL

INTERACTIONS.



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 600. MEAN STORM

MOTION VECTOR 26040.





...THOMPSON

