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WWUS20 KWNS 110544

SEL4

SPC WW 110544

IAZ000-MNZ000-111100-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 644

NWS Storm Prediction Center Norman OK

1245 AM CDT Wed Sep 11 2019



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Northern Iowa

  Southern Minnesota



* Effective this Wednesday morning from 1245 AM until 600 AM CDT.



* Primary threats include...

  Scattered damaging winds and isolated significant gusts to 75

    mph possible

  Isolated large hail events to 1 inch in diameter possible

  A tornado or two possible



SUMMARY...A complex of thunderstorms, having produced measured

severe winds and a brief tornado in the Sioux Falls area, is

expected to maintain some severe threat for a few more hours as it

moves astride a sharply defined front located very near the

Minnesota/Iowa border.  Damaging gusts will be the main concern,

though a tornado cannot be ruled out, and isolated hail also is

possible with cells ahead of the main complex.



The severe thunderstorm watch area is approximately along and 40

statute miles north and south of a line from 25 miles west southwest

of Fairmont MN to 45 miles northeast of Mason City IA. For a

complete depiction of the watch see the associated watch outline

update (WOUS64 KWNS WOU4).



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 643...



AVIATION...A few severe thunderstorms with hail surface and aloft to

1 inch. Extreme turbulence and surface wind gusts to 65 knots. A few

cumulonimbi with maximum tops to 500. Mean storm motion vector

26035.



...Edwards

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