Tornadoes and Damaging Winds in Wisconsin, May 30, 2003

Name: Tornadoes and Damaging Winds in Wisconsin, May 30, 2003
Start: 2003-05-30T13:20
End: 2003-05-30T19:00
Location: Wisconsin

May 30, 2003 · NWS MKX · 7 events in 5 counties and zones

Where it happened

Every event with a place to put it; 2 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

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 7

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 clusters of thunderstorms moved east-southeast through south-central and southeast Wisconsin on May 30, 2003, resulting in scattered reports of tornadoes and damaging, straight-line downburst winds that toppled large trees and power-lines. One thunderstorm cell attained supercell status, and after moving east out of Iowa County, turned right and moved east-southeast through the area south of Madison. A very weak tornado was noted southwest of Verona, but thereafter, only rotating wall cloud reports were received. Another tornado spun up in the rural area southwest of Brodhead (Green Co.), and proceeded to move east-southeast into extreme southwest Rock County. The parent thunderstorm for this tornado eventually moved east across the city of Beloit and dumped 1.50 inches of heavy rain, resulting in urban flooding (water up to the floor board at one location) that led to a couple vehicle accidents. Detailed information about the Dane County and Green-Rock County tornado can be found in the individual tornado reports.

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 May 30, 2:25 AM CST, 10 hours 55 minutes earlier.

Area forecast discussion, May 30, 2:25 AM CST, 10 hours 55 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
325 AM CDT FRI MAY 30 2003

FORECAST FOCUS IS TWOFOLD WITH SYS COMING DOWN IN NW FLOW TODAY/THIS
EVE. FIRST IS EXTENT OF TSTMS AND SECOND IS WIND ON BACKSIDE OF LOW
LTR TNGT/ERLY SAT.

H8/H7 WAA PCPN ALREADY WELL UNDERWAY ON NOSE OF UPR JET ACRS ERN MN
AND WC WI. THE WAA PTN TRANSLATES EWD THIS MRNG. BETTER MRNG POPS
IN THE WEST AS OPPOSED TO THE EAST WHERE CONFIDENCE NOT AS HIGH OF
PCPN MAKING IT ALL THE WAY DUE TO DRIER AMS.

ATTN THEN TURNS TO VIGOROUS WAVE DRIVING SEWD INTO CWA LTR TODAY.
MODELS APPEAR TO BRING FAVORABLE FACTORS INTO ERN CWA LTR
TODAY/ERLY THIS EVE. LOW LEVEL FRONTOGENESIS...BENEATH H7...IS
IN PLACE WITH NARROW RIBBON OF INSTAB...LI/S ARND -2 OR -3 WITH
CAPES BLO 1K. H7 OMEGA INCREASES MARKEDLY IN THE EAST AS WELL BETWEEN
18 AND 0Z. NARROW MOIST AXIS DVLPS AS WELL AS INITIALLY DRY AMS SEES
MOIST GET DRAWN NWD INTO CWA WITH H8 TDS APPCH 10C. SPC POKING SLGT
RISK INTO CWA SO WILL GO WITH LIKELY POPS...ESP IN ERN 2/3RDS OF
CWA THIS AFTN/ERLY THIS EVE.

AS WAVE AND SFC LOW PASS TO THE SE OF CWA THIS EVE...SFC THRU H7
GRAD TIGHTENS WITH STGEST NVA PROGGD FOR AFT 6Z. BETTER WIND GUSTS
APPEAR SLATED FOR SAT MRNG AS DEEPER MIXING ALLOWS FOR BETTER
MOMENTUM TRANSFER OF WINDS ALOFT.

QUIET WX THEN RTNS WITH COOLISH TEMPS EXPECTED SAT NGT WITH CLR
SKIES AND LGT WINDS UNDER SFC HI PRES.

.MKX...NONE.

Hazardous weather outlook, May 30, 8:54 AM CST, 4 hours 26 minutes before

WIZ046-047-051-052-056>060-062>072-311000-

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
954 AM CDT FRI MAY 30 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL AND SOUTHEAST
WISCONSIN.

.DAY ONE...TODAY AND TONIGHT.

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO
THIS EVENING ACROSS ALL OF SOUTH CENTRAL AND SOUTHEAST WISCONSIN.
DAMAGING THUNDERSTORM WINDS AND LARGE HAIL ARE POSSIBLE. A STRONG
COLD FRONT WILL MOVE SOUTHEAST ACROSS WISCONSIN THIS AFTERNOON INTO
THIS EVENING. THE FRONT WILL COMBINE WITH STRONG WINDS ALOFT AND
MODEST INSTABILITY TO GENERATE THUNDERSTORMS ACROSS ALL OF SOUTHERN
WISCONSIN...SOME POSSIBLY SEVERE.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH FRIDAY.

STRONG NORTH WINDS ARE EXPECTED LATE TONIGHT AND SATURDAY IN THE
WAKE OF THE FRONT...AS STRONG LOW PRESSURE MOVES SOUTHEAST ACROSS
WISCONSIN INTO OHIO. SUSTAINED NORTH WINDS OF 15 TO 30 MPH ARE
EXPECTED ACROSS SOUTH CENTRAL AND SOUTHEAST WISCONSIN...WITH GUSTS
UP TO 40 MPH POSSIBLE. GALE FORCE WINDS UP TO 35 KNOTS ARE EXPECTED
ON THE NEARSHORE WATERS OF LAKE MICHIGAN LATE TONIGHT AND
SATURDAY...WITH GALES UP TO 40 KNOTS TOWARD THE OPEN WATERS. GALE
WARNINGS ARE IN EFFECT FOR THE NEARSHORE AND OPEN WATERS OF LAKE
MICHIGAN. THE STRONG WINDS SHOULD DIMINISH SATURDAY NIGHT.

MORE THUNDERSTORMS ARE POSSIBLE TUESDAY THROUGH THURSDAY OF NEXT
WEEK.

.SPOTTER INFORMATION STATEMENT...

STORM SPOTTER GROUPS MAY BE NEEDED THIS AFTERNOON AND EVENING.

WOOD

The radar

The Milwaukee radar (KMKX), 90 km away, was scanning. The volume nearest the first event began at 19:21 UTC.

Open the radar archive at this moment

Event by event

3 tornado, 2 thunderstorm wind, 1 funnel cloud, 1 heavy rain. Local standard time, as filed.

Funnel Cloud, Green Lake

When: May 30, 1:20 PM CST
Where: Green Lake County, 2 mi SE of Princeton
Reported by: TRAINED SPOTTER
Coordinates: 42.550, -89.500

Thunderstorm Wind, Dane

When: May 30, 4:05 PM CST
Where: Dane County, 6 mi N of Mt Horeb
Measured: 56 kt (64 mph) estimated gust
Reported by: LAW ENFORCEMENT
Coordinates: 43.817, -88.717

Tornado, Dane

When: May 30, 4:25 PM CST to 4:30 PM CST
Where: Dane County, 3 mi N of Mt Vernon
Rating: F0
Path length: 3.1 mi
Path width: 25 yd
Reported by: TRAINED SPOTTER
Coordinates: 43.067, -89.418 (the zone’s center; the record gives no point)

A very weak tornado spun up north of Mt. Vernon and moved east to the rural area southwest of Verona. Only minor vegetation damage was noted, leading to an estimated wind speed of about 43 knots (50 mph). It was video taped by a mobile severe weather spotter.

Tornado, Green

When: May 30, 4:52 PM CST to 5:04 PM CST
Where: Green County, 2 mi NW of Oakley
Rating: F1
Path length: 6 mi
Path width: 100 yd
Reported by: LAW ENFORCEMENT
Coordinates: 42.680, -89.602 (the zone’s center; the record gives no point)

A supercell spawned a rain-wrapped tornado that tracked southeast through a rural portion of Green County about 6 miles southwest and south of Brodhead. One home sustained minor damage to its siding and shutters, and minor damage was noted to a storage shed; otherwise, only tree damage was reported. It is estimated that winds speeds with this tornado were about 70 knots (80 mph). This tornado continued east-southeast out of Green County at a location 6.0 miles east of Oakley (where County Trunk T doglegs west in Green County) and into the southwest corner of Rock County.

Heavy Rain, Rock

When: May 30, 5:00 PM CST to 7:00 PM CST
Where: Rock County, Beloit
Reported by: NEWSPAPER
Coordinates: 42.533, -89.367

Tornado, Rock

When: May 30, 5:04 PM CST to 5:12 PM CST
Where: Rock County, 2 mi SW of Avon
Rating: F1
Path length: 4.1 mi
Path width: 100 yd
Reported by: LAW ENFORCEMENT
Coordinates: 43.083, -89.733

This tornado, which spun up in southeast Green County, tracked east-southeast into extreme southwest Rock County at a point 2.3 miles southwest of Avon, where Douglas Road intersects County Trunk T. In Rock County, this tornado blew over a small grain bin, blew a gravity bin off its foundation, flipped and twisted a large field sprinkler system, lightly damaged a home's siding and roof, and ripped up some yard fencing. It is estimated that maximum wind were about 78 to 86 knots (90 to 100 mph). It dissipated in the wooded bottom lands of the Sugar River southeast of Avon, about three-fourths of a mile north of the Illinois state border.

Thunderstorm Wind, Fond du Lac

When: May 30, 5:20 PM CST to 6:20 PM CST
Where: Fond du Lac County, 4 mi W of Eldorado
Measured: 50 kt (58 mph) estimated gust
Reported by: LAW ENFORCEMENT
Coordinates: 42.983, -89.333

What these are

Funnel Cloud: A rotating column of cloud extending from a thunderstorm that did not reach the ground.
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.
Tornado: A violently rotating column of air in contact with the ground and extending from a thunderstorm, filed with its path, width and Fujita or Enhanced Fujita rating from the damage survey.
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 2003 Every state in 2003 This day in weather history The tornado archive for Wisconsin, 2003 Warnings in Wisconsin, May 2003

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: 5355276, 5355957, 5355958, 5356018, 5355277, 5355274, 5355275.