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WWUS20 KWNS 292041

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IAZ000-NEZ000-SDZ000-300400-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 381

NWS Storm Prediction Center Norman OK

340 PM CDT Thu Jun 29 2017



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Western Iowa

  Central and eastern Nebraska

  Southeast South Dakota



* Effective this Thursday afternoon and evening from 340 PM until

  1100 PM 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

  A tornado or two possible



SUMMARY...Storms will continue to increase and intensify across the

region this afternoon near a weak surface low and multiple surface

boundaries. Relatively strong shear and ample buoyancy will support

a large hail risk. A tornado cannot be ruled out, particularly near

a boundary that extends roughly west/east across northeast Nebraska

into western Iowa. Over time, storms will likely merge and move

east-southeastward across east-central/northeast Nebraska and

western Iowa through this evening.



The severe thunderstorm watch area is approximately along and 85

statute miles north and south of a line from 20 miles west of

Burwell NE to 35 miles east northeast of Denison IA. For a complete

depiction of the watch see the associated watch outline update

(WOUS64 KWNS WOU1).



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 380...



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 500. Mean storm motion vector

27025.



...Guyer

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