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WWUS20 KWNS 182149

SEL6

SPC WW 182149

IAZ000-MNZ000-190600-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 456

NWS Storm Prediction Center Norman OK

450 PM CDT Fri Aug 18 2017



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Northern and central Iowa

  Southern Minnesota



* Effective this Friday afternoon and Saturday morning from 450

  PM until 100 AM CDT.



* Primary threats include...

  Isolated damaging wind gusts to 70 mph possible

  Isolated large hail events to 1.5 inches in diameter possible



SUMMARY...A growing complex of strong to severe thunderstorms is

expected to move generally southeastward across the watch area

through this evening, offering occasional damaging gusts and

isolated severe hail.  Severe-storm potential becomes more uncertain

into central/southern Iowa later tonight; for now, the watch extends

to just south of the I-80 corridor.



The severe thunderstorm watch area is approximately along and 60

statute miles east and west of a line from 60 miles north northeast

of Worthington MN to 85 miles south southeast of Fort Dodge IA. For

a complete depiction of the watch see the associated watch outline

update (WOUS64 KWNS WOU6).



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 455...



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

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

few cumulonimbi with maximum tops to 450. Mean storm motion vector

32035.



...Edwards

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