Special Marine Warning
Special Marine Warning
LMZ741-742-779-190415-
/O.NEW.KLOT.MA.W.0076.260819T0218Z-260819T0415Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Chicago/Romeoville
918 PM CDT Tue Aug 18 2026
The National Weather Service in Chicago has issued a
* Special Marine Warning for...
Nearshore Waters from Wilmette Harbor to Calumet Harbor...
Open Waters from Wilmette Harbor to Michigan City out to Mid
Lake...
* Until 1115 PM CDT.
* At 918 PM CDT, strong thunderstorms were located along a line
extending from near Waukegan Harbor to 12 nm southeast of McHenry
to near Elgin, moving southeast at 30 knots.
HAZARD...Wind gusts 34 knots or greater.
SOURCE...Radar.
IMPACT...Small craft could be damaged in briefly higher winds and
suddenly higher waves.
* Locations impacted include...
Harrison-Dever Crib, Calumet Harbor, Wilmette Harbor, 31st Street
Harbor, Montrose Harbor, Monroe Harbor, Belmont Harbor, Burnham
Harbor, 59th Street Marina, Jackson Park Harbor, Diversy Harbor,
and DuSable Harbor.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Move to safe harbor until hazardous weather passes.
&&
LAT...LON 4182 8697 4176 8741 4173 8753 4175 8753
4176 8756 4183 8760 4188 8762 4189 8760
4190 8762 4196 8764 4196 8763 4199 8766
4208 8768 4211 8760 4212 8696
TIME...MOT...LOC 0218Z 292DEG 32KT 4230 8790 4221 8807 4205 8824
HAIL...0.00IN
WIND...>34KTS
$$
Yack
Flood Warning
Flood Warning
National Weather Service Grand Rapids MI
812 PM EDT Tue Aug 18 2026
MIC121-190615-
/O.NEW.KGRR.FA.W.0009.260819T0012Z-260819T0615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Muskegon MI-
812 PM EDT Tue Aug 18 2026
...FLOOD WARNING IN EFFECT UNTIL 215 AM EDT WEDNESDAY...
* WHAT...Flooding caused by excessive rainfall is expected.
* WHERE...Southeastern Muskegon County in west central Michigan...
* WHEN...Until 215 AM EDT Wednesday.
* IMPACTS...Flooding of rivers, creeks, streams, and other low-lying
and flood-prone locations is imminent or occurring.
* ADDITIONAL DETAILS...
- At 812 PM EDT, Doppler radar and automated rain gauges indicated
heavy rain. Flooding is ongoing or expected to begin shortly in
the warned area.
- Some locations that will experience flooding include...
Muskegon, Muskegon Heights, Roosevelt Park, Fruitport, Norton
Shores, Sullivan, Wolf Lake, Cloverville and Moorland.
- http://www.weather.gov/safety/flood
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don`t drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 4329 8599 4329 8595 4313 8596 4313 8627
4322 8632 4322 8630 4326 8622 4330 8607
4330 8604 4329 8604
$$
Duke
Flood Advisory
Flood Advisory
National Weather Service Gaylord MI
913 PM EDT Tue Aug 18 2026
MIC055-165-190415-
/O.NEW.KAPX.FA.Y.0042.260819T0113Z-260819T0415Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Grand Traverse MI-Wexford MI-
913 PM EDT Tue Aug 18 2026
...FLOOD ADVISORY IN EFFECT UNTIL 1215 AM EDT WEDNESDAY...
* WHAT...Flooding caused by excessive rainfall is expected.
* WHERE...A portion of northern Michigan, including the following
counties, Grand Traverse and Wexford.
* WHEN...Until 1215 AM EDT.
* IMPACTS...Minor flooding in low-lying and poor drainage areas.
* ADDITIONAL DETAILS...
- At 913 PM EDT, Doppler radar indicated heavy rain due to
thunderstorms. Minor flooding is ongoing or expected to begin
shortly in the advisory area. Between 1 and 2 inches of rain
have fallen.
- Additional rainfall amounts up to 1 inch are expected over
the area. This additional rain will result in minor flooding.
- Some locations that will experience flooding include...
Buckley.
- http://www.weather.gov/safety/flood
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don`t drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 4453 8543 4439 8547 4444 8572 4445 8576
4448 8581 4457 8581
$$
JZ
Small Craft Advisory
URGENT - MARINE WEATHER MESSAGE
National Weather Service Gaylord MI
1031 PM EDT Tue Aug 18 2026
LHZ345-LMZ323-342-344>346-190345-
/O.CON.KAPX.SC.Y.0069.000000T0000Z-260819T0300Z/
Straits of Mackinac within 5 nm of Mackinac Bridge including
Mackinac Island-
Grand Traverse Bay south of a line Grand Traverse Light to
Norwood MI-
Norwood MI to 5NM West of Mackinac Bridge including Little
Traverse Bay-Sleeping Bear Point to Grand Traverse Light MI-
Point Betsie to Sleeping Bear Point MI-
Manistee to Point Betsie MI-
1031 PM EDT Tue Aug 18 2026
...SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 11 PM EDT THIS
EVENING...
* WHAT...Highest gusts up to 25 kts from the west and highest
waves around 4 feet.
* WHERE...Portions of Lake Huron and Lake Michigan.
* WHEN...Until 11 PM EDT this evening.
* IMPACTS...Conditions will be hazardous to small craft.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Inexperienced mariners, especially those operating smaller
vessels, should avoid navigating in hazardous conditions.
&&
$$
URGENT - MARINE WEATHER MESSAGE
National Weather Service Grand Rapids MI
1013 PM EDT Tue Aug 18 2026
LMZ846>849-190800-
/O.EXT.KGRR.SC.Y.0058.000000T0000Z-260819T0800Z/
Holland to Grand Haven MI-Grand Haven to Whitehall MI-
Whitehall to Pentwater MI-Pentwater to Manistee MI-
1013 PM EDT Tue Aug 18 2026
...SMALL CRAFT ADVISORY NOW IN EFFECT UNTIL 4 AM EDT WEDNESDAY...
* WHAT...Southwest winds 10 to 20 knots becoming northwest and
waves 2 to 5 feet.
* WHERE...Holland to Manistee.
* WHEN...Until 4 AM EDT Wednesday.
* IMPACTS...Conditions will be hazardous to small craft.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Inexperienced mariners, especially those operating smaller
vessels, should avoid navigating in hazardous conditions.
&&
$$
Marine Weather Statement
Marine Weather Statement
National Weather Service Chicago/Romeoville
932 PM CDT Tue Aug 18 2026
LMZ740-777-190242-
/O.EXP.KLOT.MA.W.0075.000000T0000Z-260819T0230Z/
932 PM CDT Tue Aug 18 2026
...THE SPECIAL MARINE WARNING EXPIRED AT 930 PM CDT...
The affected areas were...
Nearshore Waters from Winthrop Harbor to Wilmette Harbor...
Open Waters from Winthrop Harbor to Wilmette Harbor out to Mid
Lake...
The thunderstorms have moved out of the area and no longer pose a
significant threat to boaters.
&&
LAT...LON 4212 8696 4211 8760 4208 8768 4214 8775
4227 8783 4234 8782 4238 8701
TIME...MOT...LOC 0232Z 324DEG 28KT 4223 8720 4212 8746 4206 8794
$$
Yack
Marine Weather Statement
National Weather Service Northern Indiana
1007 PM EDT Tue Aug 18 2026
LMZ043-046-080-190400-
1007 PM EDT Tue Aug 18 2026
...STRONG THUNDERSTORMS APPROACHING THE WATERS...
The areas affected include...
Lake Michigan Michigan City IN to St. Joseph MI 5 NM offshore to
mid-line of lake....
Michigan City IN to New Buffalo MI...
New Buffalo MI to St Joseph MI...
At 1007 PM EDT, Doppler radar indicated strong thunderstorms, capable
of producing winds to around 30 knots. These thunderstorms were
located along a line extending from near Grand Haven Light to 9 nm
west of Saugatuck Pier Heads to 23 nm west of South Haven Light to 9
nm southeast of Waukegan Harbor, moving southeast at 25 knots.
Locations impacted include...
New Buffalo, Michigan City, and St. Joseph
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Mariners can expect gusty winds to around 30 knots, locally higher
waves, and lightning strikes. Boaters should seek safe harbor
immediately until these storms pass.
&&
LAT...LON 4179 8696 4179 8697 4212 8696 4213 8657
4211 8649 4194 8658 4189 8662 4180 8675
4179 8676 4172 8691
$$
MARSILI
Hazardous Weather Outlook
Hazardous Weather Outlook...UPDATED
National Weather Service Milwaukee/Sullivan WI
753 PM CDT Tue Aug 18 2026
LMZ080-261-362-364-366-563-565-567-669-671-673-675-777-779-868-
870-872-874-876-878-200100-
Lake Michigan Michigan City IN to St. Joseph MI 5 NM offshore to
mid-line of lake.-
Lake Michigan from Seul Choix Point to Rock Island Passage 5NM
offshore to Mid Lake-
Lake Michigan South of a line from Seul Choix Point to the
Mackinac Bridge and North of a line from Charlevoix MI to South
Fox Island 5NM offshore-
Lake Michigan from Charlevoix to Point Betsie MI 5NM Offshore to
mid lake-
Lake Michigan from Point Betsie to Manistee MI 5NM offshore to
Mid Lake-
Lake Michigan from Rock Island Passage to Sturgeon Bay WI 5NM
offshore to mid lake-
Lake Michigan from Sturgeon Bay to Two Rivers WI 5NM offshore to
Mid Lake-
Lake Michigan from Two Rivers to Sheboygan WI 5NM offshore to Mid
Lake-
Lake Michigan from Sheboygan to Port Washington WI 5NM offshore
to Mid Lake-
Lake Michigan from Port Washington to North Point Light WI 5NM
offshore to Mid Lake-
Lake Michigan from North Point Light to Wind Point WI 5NM
offshore to Mid Lake-
Lake Michigan from Wind Point WI to Winthrop Harbor IL 5NM
offshore to Mid Lake-
Lake Michigan from Winthrop Harbor to Wilmette Harbor IL 5NM
offshore to Mid Lake-
Lake Michigan from Wilmette Harbor to Michigan City in 5NM
offshore to Mid Lake-
Lake Michigan from Pentwater to Manistee MI 5NM offshore to Mid
Lake-
Lake Michigan from Whitehall to Pentwater MI 5NM offshore to Mid
Lake-
Lake Michigan from Grand Haven to Whitehall MI 5NM offshore to
Mid Lake-
Lake Michigan from Holland to Grand Haven MI 5NM offshore to Mid
Lake-
Lake Michigan from South Haven to Holland MI 5NM offshore to Mid
lake-
Lake Michigan from St Joseph to South Haven MI 5NM offshore to
Mid Lake-
753 PM CDT Tue Aug 18 2026
This Hazardous Weather Outlook is for the open waters of Lake Michigan.
.DAY ONE...Tonight
Scattered thunderstorms expected through around midnight.
.DAYS TWO THROUGH SEVEN...Wednesday through Tuesday
Chance of thunderstorms on Friday.
$$
MRC
www.weather.gov/mkx
Hazardous Weather Outlook
National Weather Service Detroit/Pontiac MI
333 AM EDT Tue Aug 18 2026
LCZ460-LEZ444-LHZ361>363-421-422-441>443-462>464-190745-
Lake St Clair-
Michigan Waters of Lake Erie from Detroit River to North Cape MI-
Lake Huron from 5NM east of Mackinac Bridge to Presque Isle Lt
beyond 5 NM off shore-
Lake Huron from Presque Isle Light to Sturgeon Point MI beyond 5NM
off shore-
Lake Huron from Sturgeon Point to Alabaster MI beyond 5NM off shore-
Outer Saginaw Bay SW of Alabaster to Port Austin MI to Inner Saginaw
Bay-Inner Saginaw Bay SW of Point Au Gres to Bay Port MI-
Port Austin to Harbor Beach MI-Harbor Beach to Port Sanilac MI-
Port Sanilac to Port Huron MI-
Lake Huron from Port Austin to Harbor Beach beyond 5NM Off Shore-
Lake Huron from Harbor Beach to Port Sanilac beyond 5NM Off Shore-
Lake Huron from Port Sanilac to Port Huron beyond 5NM Off Shore-
333 AM EDT Tue Aug 18 2026
This hazardous weather outlook is for portions of Lake Erie, Lake
Huron and Lake St Clair.
.DAY ONE...Today and Tonight
Isolated to widely scattered thunderstorms will be possible late
evening through tonight. Severe weather is not expected.
.DAYS TWO THROUGH SEVEN...Wednesday through Monday
No hazardous weather is expected at this time.
.SPOTTER INFORMATION STATEMENT...
Spotter activation will not be needed today and tonight.
$$
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.
KDK
Hazardous Weather Outlook
National Weather Service Detroit/Pontiac MI
333 AM EDT Tue Aug 18 2026
MIZ047>049-053>055-060>063-068>070-075-076-082-083-190745-
Midland-Bay-Huron-Saginaw-Tuscola-Sanilac-Shiawassee-Genesee-Lapeer-
St. Clair-Livingston-Oakland-Macomb-Washtenaw-Wayne-Lenawee-Monroe-
333 AM EDT Tue Aug 18 2026
This hazardous weather outlook is for southeast Michigan.
.DAY ONE...Today and Tonight
Isolated to widely scattered thunderstorms will be possible late
evening through tonight. Severe weather is not expected.
.DAYS TWO THROUGH SEVEN...Wednesday through Monday
No hazardous weather is expected at this time.
.SPOTTER INFORMATION STATEMENT...
Spotter activation will not be needed today and tonight.
$$
