Alert archive / Illinois / Storm Warnings in 2021

Storm Warning 1, NWS Chicago, IL

December 15, 2021

NWS Chicago, IL issued this storm warning at Dec 15, 2021, 3:51 AM CST. It took effect at Dec 15, 2021, 6:00 PM CST. It was in force for 15 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Dec 15, 2021, 3:51 AM CST (09:51 UTC)
In effect from
Dec 15, 2021, 6:00 PM CST
Expired
Dec 16, 2021, 9:00 AM CST
In force
15 hr
Issued by
NWS Chicago, IL

The text

As transmitted.

945 
WHUS73 KLOT 150951
MWWLOT

URGENT - MARINE WEATHER MESSAGE
National Weather Service Chicago IL
351 AM CST Wed Dec 15 2021

LMZ743>745-151800-
/O.CON.KLOT.SC.Y.0107.211215T1500Z-211216T0000Z/
/O.UPG.KLOT.SR.A.0001.211216T0000Z-211216T1500Z/
/O.NEW.KLOT.GL.W.0022.211216T0000Z-211216T2100Z/
Calumet Harbor IL to Gary IN-Gary to Burns Harbor IN-
Burns Harbor to Michigan City IN-
351 AM CST Wed Dec 15 2021

...SMALL CRAFT ADVISORY REMAINS IN EFFECT FROM 9 AM THIS MORNING
TO 6 PM CST THIS EVENING...

...GALE WARNING IN EFFECT FROM 6 PM THIS EVENING TO 3 PM CST
THURSDAY...

* WHAT...For the Small Craft Advisory, south winds to 30 kt. For
  the Gale Warning, southwest winds to 45 kt with a few storm
  force gusts up to 50 kt. Significant waves to 7 ft. Occasional
  waves to 9 ft.

* WHERE...Portions of Lake Michigan.

* WHEN...For the Small Craft Advisory, from 9 AM to 6 PM CST
  today. For the Gale Warning, from this evening through Thursday
  morning.

* IMPACTS...Very strong winds will cause hazardous waves which
  could capsize or damage vessels and reduce visibility. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Mariners should prepare to remain in port, alter course, and/or
secure the vessel for severe conditions before conditions
deteriorate.

A Gale Warning means winds of 34 to 47 knots are imminent or
occurring. Operating a vessel in gale conditions requires
experience and properly equipped vessels. It is highly
recommended that mariners without the proper experience seek safe
harbor prior to the onset of gale conditions.

A Small Craft Advisory means that wind speeds of 21 to 33 knots
are expected to produce hazardous wave conditions to small craft.
Inexperienced mariners...especially those operating smaller
vessels should avoid navigating in these conditions.

&&

$$

LMZ740>742-151800-
/O.CON.KLOT.SC.Y.0107.211215T1500Z-211216T0000Z/
/O.UPG.KLOT.SR.A.0001.211216T0000Z-211216T1500Z/
/O.NEW.KLOT.SR.W.0001.211216T0000Z-211216T1500Z/
Winthrop Harbor to Wilmette Harbor IL-
Wilmette Harbor to Northerly Island IL-
Northerly Island to Calumet Harbor IL-
351 AM CST Wed Dec 15 2021

...SMALL CRAFT ADVISORY REMAINS IN EFFECT FROM 9 AM THIS MORNING
TO 6 PM CST THIS EVENING...

...STORM WARNING IN EFFECT FROM 6 PM THIS EVENING TO 9 AM CST
THURSDAY...

* WHAT...For the Small Craft Advisory, south winds to 30 kt. For
  the Storm Warning, southwest storm force wind gusts up to 50 kt.
  Significant waves to 9 ft. Occasional waves to 12 ft.

* WHERE...Portions of Lake Michigan.

* WHEN...For the Small Craft Advisory, from 9 AM to 6 PM CST today.
  For the Storm Warning, from this evening through Thursday 
  morning. 

* IMPACTS...Very strong winds will cause hazardous waves which
  could capsize or damage vessels and reduce visibility. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Mariners should prepare to remain in port, alter course, and/or
secure the vessel for severe conditions before conditions
deteriorate.

A Storm Warning means winds of 48 to 63 knots are imminent or
occurring. Recreational boaters should remain in port...or take
shelter until winds and waves subside. Commercial vessels should
prepare for very strong winds and dangerous sea conditions...and
consider remaining in port or taking shelter in port until winds
and waves subside.

A Small Craft Advisory means that wind speeds of 21 to 33 knots
are expected to produce hazardous wave conditions to small craft.
Inexperienced mariners...especially those operating smaller
vessels should avoid navigating in these conditions.

&&

$$
5 follow-up statements
199 
WHUS73 KLOT 151636
MWWLOT

URGENT - MARINE WEATHER MESSAGE
National Weather Service Chicago IL
1036 AM CST Wed Dec 15 2021

LMZ743>745-160045-
/O.CON.KLOT.SC.Y.0107.000000T0000Z-211216T0000Z/
/O.CON.KLOT.GL.W.0022.211216T0000Z-211216T2100Z/
Calumet Harbor IL to Gary IN-Gary to Burns Harbor IN-
Burns Harbor to Michigan City IN-
1036 AM CST Wed Dec 15 2021

...SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 6 PM CST THIS
EVENING...
...GALE WARNING REMAINS IN EFFECT FROM 6 PM THIS EVENING TO 3 PM
CST THURSDAY...

* WHAT...For the Small Craft Advisory, south winds to 30 kt. For 
  the Gale Warning, southwest winds to 45 kt with a few storm 
  force gusts up to 50 kt. Significant waves to 7 ft. Occasional 
  waves to 9 ft.

* WHERE...Portions of Lake Michigan.

* WHEN...For the Small Craft Advisory, until 6 PM CST today. For 
  the Gale Warning, from this evening through Thursday morning.

* IMPACTS...Very strong winds will cause hazardous waves which 
  could capsize or damage vessels and reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Mariners should alter plans to avoid these hazardous conditions.
Remain in port, seek safe harbor, alter course, and/or secure the
vessel for severe conditions.

&&

$$

LMZ740>742-160045-
/O.CON.KLOT.SC.Y.0107.000000T0000Z-211216T0000Z/
/O.CON.KLOT.SR.W.0001.211216T0000Z-211216T1500Z/
Winthrop Harbor to Wilmette Harbor IL-
Wilmette Harbor to Northerly Island IL-
Northerly Island to Calumet Harbor IL-
1036 AM CST Wed Dec 15 2021

...SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 6 PM CST THIS
EVENING...
...STORM WARNING REMAINS IN EFFECT FROM 6 PM THIS EVENING TO 9 AM
CST THURSDAY...

* WHAT...For the Small Craft Advisory, south winds to 30 kt. For 
  the Storm Warning, southwest storm force wind gusts up to 50 
  kt. Significant waves to 9 ft. Occasional waves to 12 ft.

* WHERE...Portions of Lake Michigan.

* WHEN...For the Small Craft Advisory, until 6 PM CST today. For 
  the Storm Warning, from this evening through Thursday morning.

* IMPACTS...Very strong winds will cause hazardous waves which 
  could capsize or damage vessels and reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Mariners should remain in port, alter course, and/or secure the
vessel for severe conditions.

&&

$$
997 
WHUS73 KLOT 152143
MWWLOT

URGENT - MARINE WEATHER MESSAGE
National Weather Service Chicago IL
343 PM CST Wed Dec 15 2021

LMZ743>745-160545-
/O.CON.KLOT.SC.Y.0107.000000T0000Z-211216T0000Z/
/O.CON.KLOT.GL.W.0022.211216T0000Z-211216T2100Z/
Calumet Harbor IL to Gary IN-Gary to Burns Harbor IN-
Burns Harbor to Michigan City IN-
343 PM CST Wed Dec 15 2021

...SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 6 PM CST THIS
EVENING...
...GALE WARNING REMAINS IN EFFECT UNTIL 3 PM CST THURSDAY...

* WHAT...For the Small Craft Advisory, south winds to 30 kt with a
  few gusts to 35 kt gales. For the Gale Warning, southwest winds
  to 45 kt with a few storm force gusts up to 50 kt. Significant 
  waves to 8 ft. Occasional waves to 10 ft.

* WHERE...Portions of Lake Michigan.

* WHEN...For the Small Craft Advisory, until 6 PM CST today. For 
  the Gale Warning, from this evening through Thursday morning.

* IMPACTS...Very strong winds will cause hazardous waves which 
  could capsize or damage vessels and reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Mariners should alter plans to avoid these hazardous conditions.
Remain in port, seek safe harbor, alter course, and/or secure the
vessel for severe conditions.

&&

$$

LMZ740>742-160545-
/O.CON.KLOT.SC.Y.0107.000000T0000Z-211216T0000Z/
/O.CON.KLOT.SR.W.0001.211216T0000Z-211216T1500Z/
Winthrop Harbor to Wilmette Harbor IL-
Wilmette Harbor to Northerly Island IL-
Northerly Island to Calumet Harbor IL-
343 PM CST Wed Dec 15 2021

...SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 6 PM CST THIS
EVENING...
...STORM WARNING REMAINS IN EFFECT UNTIL 9 AM CST THURSDAY...

* WHAT...For the Small Craft Advisory, south winds to 30 kt with a
  few gusts to 35 kt gales. For the Storm Warning, southwest 
  storm force wind gusts up to 50 kt. Significant waves to 9 ft. 
  Occasional waves to 12 ft.

* WHERE...Portions of Lake Michigan.

* WHEN...For the Small Craft Advisory, until 6 PM CST today. For 
  the Storm Warning, from this evening through Thursday morning.

* IMPACTS...Very strong winds will cause hazardous waves which 
  could capsize or damage vessels and reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Mariners should remain in port, alter course, and/or secure the
vessel for severe conditions.

&&

$$
422 
WHUS73 KLOT 160356
MWWLOT

URGENT - MARINE WEATHER MESSAGE
National Weather Service Chicago IL
956 PM CST Wed Dec 15 2021

LMZ743>745-161200-
/O.UPG.KLOT.GL.W.0022.000000T0000Z-211216T2100Z/
/O.EXA.KLOT.SR.W.0001.000000T0000Z-211216T1500Z/
/O.NEW.KLOT.GL.W.0023.211216T1500Z-211216T2100Z/
Calumet Harbor IL to Gary IN-Gary to Burns Harbor IN-
Burns Harbor to Michigan City IN-
956 PM CST Wed Dec 15 2021

...STORM WARNING IN EFFECT UNTIL 9 AM CST THURSDAY...
...GALE WARNING IN EFFECT FROM 9 AM TO 3 PM CST THURSDAY...

* WHAT...For the Storm Warning, winds up to 50 kt. For the Gale
  Warning, gales up to 35 kt.

* WHERE...Calumet Harbor IL to Gary IN, Gary to Burns Harbor IN 
  and Burns Harbor to Michigan City IN.

* WHEN...For the Storm Warning, until 9 AM CST Thursday. For the 
  Gale Warning, from 9 AM to 3 PM CST Thursday.

* IMPACTS...Very strong winds will cause hazardous waves which 
  could capsize or damage vessels and reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Mariners should remain in port, alter course, and/or secure the
vessel for severe conditions.

&&

$$

LMZ740>742-161200-
/O.CON.KLOT.SR.W.0001.000000T0000Z-211216T1500Z/
Winthrop Harbor to Wilmette Harbor IL-
Wilmette Harbor to Northerly Island IL-
Northerly Island to Calumet Harbor IL-
956 PM CST Wed Dec 15 2021

...STORM WARNING REMAINS IN EFFECT UNTIL 9 AM CST THURSDAY...

* WHAT...storm force wind gusts up to 50 kt. Significant waves to
  9 ft. Occasional waves to 12 ft.

* WHERE...Portions of Lake Michigan.

* WHEN...For the Small Craft Advisory, until 6 PM CST today. For 
  the Storm Warning, from this evening through Thursday morning.

* IMPACTS...Very strong winds will cause hazardous waves which 
  could capsize or damage vessels and reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Mariners should remain in port, alter course, and/or secure the
vessel for severe conditions.

&&

$$
218 
WHUS73 KLOT 160901
MWWLOT

URGENT - MARINE WEATHER MESSAGE
National Weather Service Chicago IL
301 AM CST Thu Dec 16 2021

LMZ743>745-161715-
/O.CON.KLOT.SR.W.0001.000000T0000Z-211216T1500Z/
/O.CON.KLOT.GL.W.0023.211216T1500Z-211216T2100Z/
Calumet Harbor IL to Gary IN-Gary to Burns Harbor IN-
Burns Harbor to Michigan City IN-
301 AM CST Thu Dec 16 2021

...STORM WARNING REMAINS IN EFFECT UNTIL 9 AM CST THIS MORNING...

...GALE WARNING REMAINS IN EFFECT FROM 9 AM THIS MORNING TO 3 PM
CST THIS AFTERNOON...

* WHAT...For the Storm Warning, southwest gales to 45 kt with
  occasional storm force winds to 50 kt. For the Gale Warning,
  southwest gales up to 40 kt. Significant waves to 7 ft.
  Occasional waves to 9 ft.

* WHERE...Gary to Burns Harbor IN, Burns Harbor to Michigan City 
  IN and Calumet Harbor IL to Gary IN.

* WHEN...For the Storm Warning, until 9 AM CST this morning. For 
  the Gale Warning, from 9 AM this morning to 3 PM CST this 
  afternoon.

* IMPACTS...Very strong winds will cause hazardous waves which 
  could capsize or damage vessels and reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Mariners should remain in port, alter course, and/or secure the
vessel for severe conditions.

&&

$$

LMZ740>742-161500-
/O.CON.KLOT.SR.W.0001.000000T0000Z-211216T1500Z/
Winthrop Harbor to Wilmette Harbor IL-
Wilmette Harbor to Northerly Island IL-
Northerly Island to Calumet Harbor IL-
301 AM CST Thu Dec 16 2021

...STORM WARNING REMAINS IN EFFECT UNTIL 9 AM CST THIS MORNING...

* WHAT...Storm force wind gusts up to 50 to 55 kt. Significant 
  waves to 7 ft. Occasional waves to 9 ft.

* WHERE...Northerly Island to Calumet Harbor IL, Winthrop Harbor 
  to Wilmette Harbor IL and Wilmette Harbor to Northerly Island 
  IL.

* WHEN...Until 9 AM CST this morning.

* IMPACTS...Very strong winds will cause hazardous waves which 
  could capsize or damage vessels and reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Mariners should remain in port, alter course, and/or secure the
vessel for severe conditions.

&&

$$
291 
WHUS73 KLOT 161437
MWWLOT

URGENT - MARINE WEATHER MESSAGE
National Weather Service Chicago IL
837 AM CST Thu Dec 16 2021

LMZ743>745-162100-
/O.EXP.KLOT.SR.W.0001.000000T0000Z-211216T1500Z/
/O.CON.KLOT.GL.W.0023.211216T1500Z-211216T2100Z/
Calumet Harbor IL to Gary IN-Gary to Burns Harbor IN-
Burns Harbor to Michigan City IN-
837 AM CST Thu Dec 16 2021

...GALE WARNING REMAINS IN EFFECT UNTIL 3 PM CST THIS AFTERNOON...
...STORM WARNING WILL EXPIRE AT 9 AM CST THIS MORNING...

* WHAT...West winds 20 to 25 kt with gusts up to 35 kt and waves 4
  to 7 ft expected.

* WHERE...Gary to Burns Harbor IN, Burns Harbor to Michigan City 
  IN and Calumet Harbor IL to Gary IN.

* WHEN...For the Storm Warning, until 9 AM CST this morning. For 
  the Gale Warning, from 9 AM this morning to 3 PM CST this 
  afternoon.

* IMPACTS...Strong winds will cause hazardous waves which could 
  capsize or damage vessels and reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Mariners should alter plans to avoid these hazardous conditions.
Remain in port, seek safe harbor, alter course, and/or secure the
vessel for severe conditions.

&&

$$

LMZ740>742-162100-
/O.EXP.KLOT.SR.W.0001.000000T0000Z-211216T1500Z/
/O.EXA.KLOT.GL.W.0023.211216T1500Z-211216T2100Z/
Winthrop Harbor to Wilmette Harbor IL-
Wilmette Harbor to Northerly Island IL-
Northerly Island to Calumet Harbor IL-
837 AM CST Thu Dec 16 2021

...GALE WARNING IN EFFECT UNTIL 3 PM CST THIS AFTERNOON...
...STORM WARNING WILL EXPIRE AT 9 AM CST THIS MORNING...

* WHAT...West winds 20 to 25 kt with gusts up to 35 kt and waves 3
  to 5 ft expected.

* WHERE...Winthrop Harbor to Wilmette Harbor IL, Wilmette Harbor 
  to Northerly Island IL and Northerly Island to Calumet Harbor 
  IL.

* WHEN...For the Storm Warning, until 9 AM CST this morning. For 
  the Gale Warning, from 9 AM this morning to 3 PM CST this 
  afternoon.

* IMPACTS...Strong winds will cause hazardous waves which could
  capsize or damage vessels and reduce visibility.

  PRECAUTIONARY/PREPAREDNESS ACTIONS...

Mariners should alter plans to avoid these hazardous conditions.
Remain in port, seek safe harbor, alter course, and/or secure the
vessel for severe conditions.

&&

$$

The office that day

Everything else NWS Chicago, IL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 14, 9:14 PM CSTStorm WatchLOT7 hr
Dec 15, 3:09 AM CSTHigh Wind WarningLOTBoone, Cook, DeKalb, DuPage, Ford, Grundy and 12 more30 hr
Dec 15, 3:51 AM CSTGale WarningLOT18 hr

Nearby

Storm Warnings in Illinois, 2021Every storm warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text.