Heavy Rain in Wisconsin, September 18 to 19, 2001

Name: Heavy Rain in Wisconsin, September 18 to 19, 2001
Start: 2001-09-18T20:00
End: 2001-09-19T06:00
Location: Wisconsin

September 18 to 19, 2001 · NWS MKX · 9 events in 9 counties and zones

22 inches of rain across parts of south-central and southeast Wisconsin. 5 inches during the overnight hours.

Where it happened

Every event with a place to put it; 9 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: None recorded
Crop damage: None recorded
Events: 9

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 MKX wrote it up.

Several rounds of moderate to heavy rains dumped .75 to 2.22 inches of rain across parts of south-central and southeast Wisconsin. Many locations had 1 to 1.5 inches during the overnight hours. The Racine city area (Racine Co.) recorded 2.16 to 2.22 inches (probably record amounts for the 24 hour period ending at 0600CST on September 19, 2001), resulting in minor urban flooding. There were other scattered reports of water briefly covering some roads in low-lying areas across the remainder of south-central and southeast Wisconsin. Additional rainfall reports include: Clinton WWTP (Rock Co.) 1.38 inches, Kenosha Municipal Airport 1.38 inches, Blanchardville (7 N Argyle, Lafayette Co.) 1.33 inches, Genoa City (Walworth Co.) 1.28 inches, Milwaukee Mitchell Field (Milwaukee Co.) 1.25 inches, Eagle 1.15 inches (amateur radio operator), Ft. Atkinson WWTP 1.06 inches, Beloit College (Rock Co.) 1.04 inches, and the Dodgeville WWTP (Iowa Co.) 0.92 inches. These heavy rains ultimately lead to total September 2001 rainfall amounts (TV school network reports) of 6.42 inches in Brodhead (Green Co.), 7.03 inches in Barneveld (Iowa Co.), 7.72 inches in Janesville (Rock Co.), 6.92 inches in Lake Geneva (Walworth Co.), 6.03 inches in Wisconsin Dells (Columbia Co.), 6.63 inches on the southwest side of Madison (Dane Co.).

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 Milwaukee, WI wrote its last area forecast discussion before the first event at Sep 18, 2:30 PM CST, 5 hours 30 minutes earlier.

Area forecast discussion, Sep 18, 2:30 PM CST, 5 hours 30 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
330 PM CDT TUE SEP 18 2001

FORECAST FOCUS ON STRENGTH OF LOW AND RAINFALL AMOUNTS.

LOW PRESSURE CURRENTLY OVER WRN MO WITH 3 MB/3 HR PRES FALLS
NORTHEAST OF LOW. LARGE AREA OF RAIN OVER IA AND WRN IL WITHIN
REGION OF WAA AND DIFF CVA. EXPECT RAIN TO MOVE INTO SW ZONES
SHORTLY AFTER 5 PM.

ETA AND AVN HAVE SIMILAR TRACK OF LOW...BRINGING LOW THROUGH SRN TIP
OF LM AND THEN NEWD. AVN IS STRONGER AND FASTER AND STILL PRODUCING
2 INCH QPF AMOUNTS. AVN QPF IS NOT VERIFYING AND HIGH QPF LIKELY
FROM CONVECTIVE FEEDBACK. NGM IS TOO DRY AND FARTHER EAST. MAINLY
USED ETA FOR GUIDANCE.

MAIN UPPER TROUGH AXIS STILL OVER PLAINS AND PROGGED TO AMPLIFY AS
CYCLOGENESIS CONTINUES TONIGHT. SYSTEM TO BECOME VERTICALLY STACKED
BY 18Z WED WITH LOW OVER SRN LM. ETA OMEGA FIELDS AND ISENTROPIC LIFT
STRONGEST OVER SE WI WHERE BEST THETAE ADVECTION...DIFF CVA AND
LIFT FROM LT FNT QUAD WILL OCCUR. MIXING RATIOS OF 6 G/KG EXPECTED TO
ADVECT IN UP TO 700 MB WITH PWS INCREASING TO 1.4 INCHES. EXPECT SOME
RAINFALL TOTALS SLIGHTLY OVER AN INCH IN SE WI WITH TOTAL AMOUNTS OF
1/2 TO 1 INCH ELSEWHERE.

UPPER TROUGH AXIS PUSHES ACROSS CWA ON WED AND WILL SEE RAIN
DIMINISHING DURING THE DAY FROM WEST TO EAST. ETA AND NGM HANG ON TO
HI RH UNDER 700 MB AS SUBSIDENCE AND GOOD CAA IS LACKING. SO WILL
KEEP SKY CONDITIONS MO CLDY. ANOTHER ROBUST SHORTWAVE AND ASSOCIATED
JET STREAK WITHIN NW FLOW IS PROGGED TO AFFECT CWA THU NT. NOT A LOT
OF MOISTURE WITH MIXING RATIOS OF 4 G/KG UP TO 700 MB...BUT WITH
DECENT LIFT WILL GO WITH 50 POPS.

WENT WITH COOLER MAX TEMPS FOR WED WITH THE EXCEPTION OF FAR SE WI...
OTHERWISE GUIDANCE LOOKS GOOD.

.MKX...NONE.

MG

The radar

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

Open the radar archive at this moment

Event by event

9 heavy rain. Local standard time, as filed.

Heavy Rain, Lafayette

When: September 18, 8:00 PM CST to September 19, 6:00 AM CST
Where: Lafayette County, 7 mi N of Argyle
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.661, -90.132 (the zone’s center; the record gives no point)

Heavy Rain, Green

When: September 18, 8:00 PM CST to September 19, 6:00 AM CST
Where: Green County, Monroe
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.680, -89.602 (the zone’s center; the record gives no point)

Heavy Rain, Rock

When: September 18, 8:00 PM CST to September 19, 6:00 AM CST
Where: Rock County, Beloit
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.671, -89.072 (the zone’s center; the record gives no point)

Heavy Rain, Jefferson

When: September 18, 8:00 PM CST to September 19, 6:00 AM CST
Where: Jefferson County, 3 mi SE of Sullivan
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 43.021, -88.776 (the zone’s center; the record gives no point)

Heavy Rain, Waukesha

When: September 18, 8:00 PM CST to September 19, 6:00 AM CST
Where: Waukesha County, Eagle
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 43.018, -88.304 (the zone’s center; the record gives no point)

Heavy Rain, Milwaukee

When: September 18, 8:00 PM CST to September 19, 6:00 AM CST
Where: Milwaukee County, Milwaukee Mtchell Ar
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 43.022, -87.929 (the zone’s center; the record gives no point)

Heavy Rain, Walworth

When: September 18, 8:00 PM CST to September 19, 6:00 AM CST
Where: Walworth County, Genoa City
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.669, -88.542 (the zone’s center; the record gives no point)

Heavy Rain, Kenosha

When: September 18, 8:00 PM CST to September 19, 6:00 AM CST
Where: Kenosha County, Kenosha Muni Arpt
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 42.573, -87.840 (the zone’s center; the record gives no point)

Heavy Rain, Iowa

When: September 18, 8:00 PM CST to September 19, 6:00 AM CST
Where: Iowa County, Dodgeville
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 43.001, -90.135 (the zone’s center; the record gives no point)

What these are

Heavy Rain: Rainfall totals unusual for the place and season that did not produce a flood.

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

The same day elsewhere

Every storm in Wisconsin in 2001 Every state in 2001 This day in weather history Warnings in Wisconsin, 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: 5267942, 5267943, 5267944, 5268031, 5268032, 5268033, 5268034, 5268035, 5268036.