Illinois, 2001

Hail and Damaging Winds in Illinois, September 3, 2001

September 3, 2001 · NWS LOT · 4 events in 2 counties and zones

A line of thunderstorms moved into extreme northern Illinois during the late afternoon and early evening of Sept 3rd 2001. Trees were blown down in Fox Lake in Lake county and trees and power lines were blown down in Spring Grove and Crystal Lake in McHenry county.

Where it happened

Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. 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

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The toll

Deaths
0
Injuries
0
Property damage
$10,000
Crop damage
None recorded
Events
4

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.

A line of thunderstorms moved into extreme northern Illinois during the late afternoon and early evening of Sept 3rd 2001. Trees were blown down in Fox Lake in Lake county and trees and power lines were blown down in Spring Grove and Crystal Lake in McHenry county. Dime size hail fell in Marengo in McHenry county. A house was struck by lightning and the roof caught fire in Marengo.

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 Sep 3, 12:45 PM CST, 4 hours earlier.

Area forecast discussion, Sep 3, 12:45 PM CST, 4 hours before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO IL
145 PM CDT MON SEP 3 2001

MSAS ANALYSIS HAS BEEN SHOWING INCREASING INSTABILITY AND MOISTURE
CONVERGENCE ALONG FRONT FROM MID LAKE MICHIGAN INTO NORTHEAST IOWA
LAST FEW HOURS (BEFORE LOSS OF MOST METARS AT 18Z). LITTLE
CONVECTIVE INHIBITION INDICATED SO THERE WOULD SEEM TO BE NOT MUCH
DOUBT THAT FRONT WILL COME THROUGH IN THE EVENING WITH SCATTERED
THUNDERSTORMS ALONG IT. POPS WILL BE OMITTED IN ZONES. AS PER
SPC...PERHAPS A FEW WITH STRONG WINDS.

AFTER THAT...SEVERAL COOLER SUNNY DAYS INDICATED AS ANOTHER HIGH
BUILDS INTO THE UPPER MISSISSIPPI VALLEY AND THEN EASTWARD.  850
TEMPS MARGINAL FOR CLOUDS AT ALL, SO AT THIS POINT WILL NOT TRY TO
FORECAST  DEVELOPMENT OF LAKE EFFECT CLOUDINESS TUESDAY P.M. INTO
EARLY WEDNESDAY. LAKE TEMPS IN 60S THOUGH WILL HELP KEEP HIGHS
SUPPRESSED CLOSER TO THE LAKE.  3 MOS CONSENSUS USUALLY HARD TO BEAT
AND WILL GO THIS WAY AGAIN TODAY.

IN THIS SEEMINGLY ENDING PATTERN ANOTHER FRONT COMES THROUGH ON
FRIDAY WITH A CHANCE OF PRECIP FOLLOWED BY A COUPLE DRY DAYS. LATEST
EXTENDED GUIDANCE SIMILAR TO EXISTING EXTENDED PORTION OF ZONES SO
NO MAJOR CHANGES PLANNED.

.CHI...NONE

KAPLAN

In the hours before

Special weather statement, Sep 3, 10:48 AM CST, 5 hours 57 minutes before
ILZ003>006-008-010>014-019>023-032>033-039-INZ001>002-010>011-019-
041100-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO IL
1149 AM CDT/EST MON SEP 3 2001

FOR NORTH CENTRAL AND NORTHEAST ILLINOIS AND NORTHWEST INDIANA...

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATER THIS AFTERNOON OR
EARLY THIS EVENING...GENERALLY NORTH OF A LINE FROM ROCKFORD TO JOLIET
TO VALPARAISO.

A LINE OF SCATTERED SHOWERS AND THUNDERSTORMS IS LIKELY TO MOVE INTO
THE AREA FROM THE NORTH AFTER 4 PM. THE MAIN THREAT WILL BE DAMAGING
WINDS FROM A FEW OF THE STRONGEST STORMS.

KAPLAN

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

2 thunderstorm wind, 1 hail, 1 lightning. Local standard time, as filed.

Thunderstorm Wind, Lake

When
September 3, 4:45 PM CST
Where
Lake County, Fox Lake
Measured
50 kt (58 mph)
Reported by
BROADCAST MEDIA
Coordinates
42.400, -88.167

Thunderstorm Wind, McHenry

When
September 3, 4:47 PM CST to 5:00 PM CST
Where
McHenry County, Spring Grove
Measured
50 kt (58 mph)
Reported by
LAW ENFORCEMENT
Coordinates
42.450, -88.233

Hail, McHenry

When
September 3, 5:30 PM CST
Where
McHenry County, Marengo
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
42.250, -88.600

Lightning, McHenry

When
September 3, 6:17 PM CST
Where
McHenry County, Marengo
Property damage
$10,000
Reported by
NEWSPAPER
Coordinates
42.324, -88.452 (the zone’s center; the record gives no point)

What these are

Thunderstorm Wind
Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.
Hail
Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
Lightning
A lightning strike that killed, injured or caused damage.

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

The same day elsewhere

More

Every storm in Illinois in 2001Every state in 2001This day in weather historyWarnings in Illinois, September 2001

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: 5267512, 5267511, 5267513, 5267514.