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384 

WWUS20 KWNS 192149

SEL2

SPC WW 192149

IAZ000-NEZ000-SDZ000-200500-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 422

NWS Storm Prediction Center Norman OK

450 PM CDT Wed Jul 19 2017



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Northwest Iowa

  Northern Nebraska

  Southeast South Dakota



* Effective this Wednesday afternoon from 450 PM until Midnight

  CDT.



* Primary threats include...

  Scattered large hail and isolated very large hail events to 2.5

    inches in diameter possible

  Scattered damaging wind gusts to 70 mph possible



SUMMARY...A cluster of storms along the South Dakota and Nebraska

border vicinity will likely continue to spread generally eastward

along an effective boundary, aided by a very hot/moist air mass near

and south of this boundary. Sporadic large hail will be possible

aside from damaging winds.



The severe thunderstorm watch area is approximately along and 50

statute miles north and south of a line from 30 miles west northwest

of Ainsworth NE to 40 miles northeast of Sioux City IA. For a

complete depiction of the watch see the associated watch outline

update (WOUS64 KWNS WOU2).



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 420...WW 421...



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

2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A

few cumulonimbi with maximum tops to 600. Mean storm motion vector

28025.



...Guyer

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