Marine Thunderstorm Winds in Lake Michigan, August 7, 2007

Name: Marine Thunderstorm Winds in Lake Michigan, August 7, 2007
Start: 2007-08-07T02:55
End: 2007-08-07T04:15
Location: Lake Michigan

August 7, 2007 · NWS LOT · 3 events in 2 counties and zones

Strong storms moved across southern Lake Michigan during the early morning hours of August 7th.

Where it happened

Every event with a place to put it. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 3

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS LOT wrote it up.

Strong storms moved across southern Lake Michigan during the early morning hours of August 7th.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Chicago, IL wrote its last area forecast discussion before the first event at Aug 7, 2:30 AM CST, 25 minutes earlier.

Area forecast discussion, Aug 7, 2:30 AM CST, 25 minutes before

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Hazardous weather outlook, Aug 6, 3:30 PM CST, 11 hours 25 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
430 PM CDT MON AUG 6 2007

ILZ003>006-008-010>014-019>022-023-032-033-039-INZ001-002-010-011-
019-070930-
WINNEBAGO-BOONE-MCHENRY-LAKE IL-OGLE-LEE-DE KALB-KANE-DU PAGE-COOK-
LA SALLE-KENDALL-GRUNDY-WILL-KANKAKEE-LIVINGSTON-IROQUOIS-FORD-
LAKE IN-PORTER-NEWTON-JASPER-BENTON-
430 PM CDT MON AUG 6 2007

THIS PORTION OF THE HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL
AND NORTHEAST ILLINOIS...AND NORTHWEST INDIANA.

.DAY ONE... TONIGHT

A FLASH FLOOD WATCH WILL BE IN EFFECT TONIGHT THROUGH TUESDAY
AFTERNOON FROM HEAVY RAINFALL FROM THUNDERSTORMS. THERE IS A SLIGHT
RISK THAT SOME OF THE THUNDERSTORMS TONIGHT COULD BE SEVERE.

.DAYS TWO THROUGH SEVEN... TUESDAY THROUGH SUNDAY

THE FLASH FLOOD WATCH WILL CONTINUE THROUGH TUESDAY AFTERNOON. MORE
THUNDERSTORMS ARE EXPECTED INTO THE MORNING HOURS ON TUESDAY BEFORE
BECOMING MORE SCATTERED TUESDAY AFTERNOON. THERE IS A SLIGHT RISK OF
SEVERE THUNDERSTORMS TUESDAY. HEAVY RAINFALL WILL ALSO REMAIN
POSSIBLE. MORE THUNDERSTORMS ARE POSSIBLE TUESDAY NIGHT IN NORTHWEST
INDIANA AND OVER THE ENTIRE OUTLOOK AREA AGAIN WEDNESDAY NIGHT
THROUGH THURSDAY NIGHT.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BECOME NECESSARY.

&&

COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE
NWS CHICAGO WEBPAGE: WEATHER.GOV/CHICAGO (LOWER CASE)

LMZ740>745-766-070930-
WINTHROP HARBOR IL TO MICHIGAN CITY IN-
LAKE MICHIGAN-
430 PM CDT MON AUG 6 2007

THIS PORTION OF THE HAZARDOUS WEATHER OUTLOOK IS FOR THE ILLINOIS
AND INDIANA WATERS OF LAKE MICHIGAN.

.DAY ONE... TONIGHT

THUNDERSTORMS ARE LIKELY THIS EVENING. A FEW STORMS MAY PRODUCE WIND
GUSTS IN EXCESS OF 35 KNOTS AFTER MIDNIGHT TONIGHT.

.DAYS TWO THROUGH SEVEN... TUESDAY THROUGH SUNDAY

THUNDERSTORMS ARE AGAIN LIKELY ON TUESDAY. THERE IS A SLIGHT RISK OF
SEVERE THUNDERSTORMS WITH THE MAIN THREAT BEING THUNDERSTORM WIND
GUSTS IN EXCESS OF 35 KNOTS.

THERE IS ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS WEDNESDAY NIGHT
THROUGH THURSDAY NIGHT.

&&

COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE
NWS CHICAGO WEBPAGE: WEATHER.GOV/CHICAGO (LOWER CASE)

In the hours before

Local storm report, Aug 7, 2:42 AM CST, 13 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
342 AM CDT TUE AUG 07 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0200 AM     FLASH FLOOD      ROCKFORD                42.27N 89.06W
08/07/2007                   WINNEBAGO          IL   LAW ENFORCEMENT

            APPROXIMATELY 20 INTERSECTIONS FLOODED...6 CARS STRANDED
            IN CITY OF ROCKFORD. FROM 911 CENTER.

0322 AM     HEAVY RAIN       ROCKFORD                42.27N 89.06W
08/07/2007  M4.83 INCH       WINNEBAGO          IL   CO-OP OBSERVER

            4 HOUR RAINFALL...SINCE 11 PM MONDAY EVENING.

0325 AM     FLASH FLOOD      WOODSTOCK               42.31N 88.44W
08/07/2007                   MCHENRY            IL   TRAINED SPOTTER

            INTERSECTION OF ROUTES 47 AND 120 SHUT DOWN DUE TO 2 FEET
            OF STANDING WATER. WILLOW AND CLAY STREET SHUT DOWN DUE
            TO WAIST DEEP WATER. PLOICE CONDUCTING RESCUES FROM
            STRANDED VEHICLES. WATER A FOOT DEEP ON WASHINGTON
            STREET.

&&

RATZER

The radar

The Chicago radar (KLOT), 52 km away, was scanning. The volume nearest the first event began at 08:53 UTC.

Open the radar archive at this moment

Event by event

3 marine thunderstorm wind. Local standard time, as filed.

Marine Thunderstorm Wind, Wilmette Hbr to Meigs Field Il

When: August 7, 2:55 AM CST
Where: Wilmette Hbr to Meigs Field Il forecast zone, Harrison-Dever Crib
Measured: 36 kt (41 mph) measured gust
Reported by: C-MAN Station
Coordinates: 41.900, -87.600

Marine Thunderstorm Wind, Burn Hbr to Michigan City in

When: August 7, 4:00 AM CST
Where: Burn Hbr to Michigan City in forecast zone, Michigan City
Measured: 35 kt (40 mph) measured gust
Reported by: C-MAN Station
Coordinates: 41.720, -86.900

Marine Thunderstorm Wind, Burn Hbr to Michigan City in

When: August 7, 4:15 AM CST
Where: Burn Hbr to Michigan City in forecast zone, Michigan City
Measured: 38 kt (44 mph) measured gust
Reported by: C-MAN Station
Coordinates: 41.720, -86.900

What these are

Marine Thunderstorm Wind: Thunderstorm winds of 34 knots or more over coastal or lake waters.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Lake Michigan in 2007 Every state in 2007 This day in weather history

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 54779, 54777, 54778.