422 

WHUS53 KLOT 180106
SMWLOT
LMZ740-741-777-779-180300-
/O.NEW.KLOT.MA.W.0027.260418T0106Z-260418T0300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Chicago/Romeoville
806 PM CDT Fri Apr 17 2026

The National Weather Service in Chicago has issued a

* Special Marine Warning for...

  Nearshore Waters from Winthrop Harbor to Northerly Island...
  Open Waters from Winthrop Harbor to Michigan City out to Mid
Lake...

* Until 1000 PM CDT.

* At 806 PM CDT, severe thunderstorms capable of producing
  waterspouts were located along a line extending from 7 nm northwest
  of Kenosha to near McHenry to 16 nm west of Elgin, moving east at
  30 knots.

  HAZARD...Waterspouts and wind gusts in excess of 65 knots.

  SOURCE...Radar.

  IMPACT...Waterspouts can easily overturn boats and create locally
           hazardous seas. Boats could suffer significant structural
           damage in high winds. Small craft could capsize in
           suddenly higher waves.

* Locations impacted include...
  Harrison-Dever Crib, Wilmette Harbor, Winthrop Harbor, Montrose
  Harbor, Monroe Harbor, Waukegan Harbor, Belmont Harbor, Diversy
  Harbor, and DuSable Harbor.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1100 PM CDT for northeastern
Illinois...and the adjacent waters of Lake Michigan.

Move to safe harbor immediately as gusty winds and high waves are
expected.

Thunderstorms can produce sudden waterspouts. Waterspouts can easily
overturn boats and create locally hazardous seas. Seek safe harbor
immediately.

&&

LAT...LON 4246 8702 4209 8696 4209 8697 4186 8738
      4188 8762 4189 8762 4189 8760 4190 8762
      4206 8767 4214 8775 4227 8783 4233 8783
      4239 8780 4248 8780
TIME...MOT...LOC 0106Z 279DEG 28KT 4266 8800 4238 8825 4202 8865

WATERSPOUT...POSSIBLE
HAIL...0.00IN
WIND...65KTS

$$

Yack






786 

WHUS53 KGRR 180150
SMWGRR
LMZ844>847-872-874-876-878-180445-
/O.NEW.KGRR.MA.W.0019.260418T0150Z-260418T0445Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Grand Rapids MI
950 PM EDT Fri Apr 17 2026

The National Weather Service in Grand Rapids has issued a

* Special Marine Warning for...
  Nearshore and Open Waters from St Joseph to Whitehall MI...

* Until 1245 AM EDT.

* At 950 PM EDT, strong thunderstorms were located along a line
  extending from 20 nm east of North Pt. Lt. to 10 nm east of
  Winthrop Harbor to 8 nm east of Wilmette Harbor, moving east at 30
  knots.

  HAZARD...Wind gusts to 40 knots and small hail.

  SOURCE...Radar.

  IMPACT...Small craft could be damaged in briefly higher winds and
           suddenly higher waves.

* Locations impacted include...
  South Haven Light, St. Joseph Light, White Lake Pier Heads, Mona
  Lake Channel, Holland Light, The White Lake Pierheads, Muskegon
  Light, and St. Joseph.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor until hazardous weather passes.

&&

LAT...LON 4213 8656 4212 8696 4337 8714 4340 8643
      4312 8627 4277 8621 4248 8625 4225 8635
      4211 8649
TIME...MOT...LOC 0150Z 262DEG 31KT 4308 8740 4247 8757 4208 8749

HAIL...<.75IN
WIND...40KTS

$$

NJJ