

510 

WWUS20 KWNS 112037

SEL8

SPC WW 112037

MIZ000-LHZ000-LMZ000-120300-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 428

NWS Storm Prediction Center Norman OK

440 PM EDT Wed Aug 11 2021



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Northern Lower Michigan

  Lake Huron

  Lake Michigan



* Effective this Wednesday afternoon and evening from 440 PM

  until 1100 PM EDT.



* Primary threats include...

  Scattered damaging wind gusts to 70 mph possible

  Isolated large hail events to 1.5 inches in diameter possible

  A tornado or two possible



SUMMARY...Severe storms will spread into northern Lower Michigan

from Lake Michigan over the next couple of hours.  Northern Lower

Michigan was not affected by earlier storms to the south, and the

storm environment remains favorable for a mix of supercells and

clusters/line segments capable of producing damaging winds to 70

mph, isolated large hail to 1.5 inch diameter, and an isolated

tornado or two through late evening.



The severe thunderstorm watch area is approximately along and 75

statute miles east and west of a line from 15 miles east northeast

of Pellston MI to 40 miles east of Manistee MI. For a complete

depiction of the watch see the associated watch outline update

(WOUS64 KWNS WOU8).



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 424...WW 425...WW

426...WW 427...



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 500. Mean storm motion vector

28035.



...Thompson

