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WWUS20 KWNS 160050

SEL7

SPC WW 160050

ILZ000-WIZ000-160700-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 217

NWS Storm Prediction Center Norman OK

755 PM CDT Mon May 15 2017



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Northern Illinois

  Southern Wisconsin



* Effective this Monday night and Tuesday morning from 755 PM

  until 200 AM CDT.



* Primary threats include...

  Isolated very large hail events to 2 inches in diameter possible

  Isolated damaging wind gusts to 70 mph possible

  A tornado or two possible



SUMMARY...A compact linear convective system will continue

east-southeastward this evening across southern Wisconsin and

northern Illinois, favoring a west/northeast-east/southeast-oriented

boundary across the region. Damaging winds and severe hail should be

the main concerns.



The severe thunderstorm watch area is approximately along and 40

statute miles north and south of a line from 70 miles west of

Janesville WI to 55 miles east of Rockford IL. 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 213...WW 214...WW

215...WW 216...



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

29040.



...Guyer

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