WWUS20 KWNS 182346

SEL7  

SPC WW 182346

IAZ000-MNZ000-190500-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 597

NWS Storm Prediction Center Norman OK

650 PM CDT Tue Aug 18 2026



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of 

  Northern Iowa

  Far Southwest Minnesota



* Effective this Tuesday night from 650 PM until Midnight CDT.



* Primary threats include...

  Scattered large hail and isolated very large hail events to 2

    inches in diameter possible

  Scattered damaging wind gusts to 70 mph possible



SUMMARY...Supercells should further develop and track southeastward

this evening from far southwest Minnesota into parts of northern

Iowa along and ahead of a cold front. Large hail up to 2 inches in

diameter should be the main threat with this activity, but

occasional severe/damaging winds may also occur.



The severe thunderstorm watch area is approximately along and 40

statute miles north and south of a line from 35 miles southwest of

Worthington MN to 15 miles east northeast of Waterloo IA. 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 595...WW 596...



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 500. Mean storm motion vector

31025.



...Gleason