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188 

WWUS20 KWNS 170055

SEL0

SPC WW 170055

IAZ000-ILZ000-INZ000-NEZ000-170800-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 170

NWS Storm Prediction Center Norman OK

755 PM CDT Thu May 16 2019



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Iowa

  Northern Illinois

  Northwest Indiana

  Eastern Nebraska



* Effective this Thursday night and Friday morning from 755 PM

  until 300 AM CDT.



* Primary threats include...

  Scattered large hail likely with isolated very large hail events

    to 2 inches in diameter possible

  Isolated damaging wind gusts to 70 mph possible



SUMMARY...Widely scattered thunderstorms will continue to increase

across the region this evening. A very unstable environment,

accentuated by very steep mid-level lapse rates, will support storms

capable of large hail as the primary hazard. Storms could eventually

organize with some potential for damaging winds as well.



The severe thunderstorm watch area is approximately along and 45

statute miles north and south of a line from 15 miles south

southwest of Sioux City IA to 75 miles east southeast of Marseilles

IL. For a complete depiction of the watch see the associated watch

outline update (WOUS64 KWNS WOU0).



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.



&&



AVIATION...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 550. Mean storm motion vector

28020.



...Guyer

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