Tornadoes and Flash Flood in Wisconsin, July 10, 2008

Name: Tornadoes and Flash Flood in Wisconsin, July 10, 2008
Start: 2008-07-10T12:20
End: 2008-07-10T19:00
Location: Wisconsin

July 10, 2008 · NWS MKX · 21 events in 15 counties and zones

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: $600,000
Crop damage: None recorded
Events: 21

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.

Two rounds of severe weather affected south-central and southeast Wisconsin on July 10th. An initial cluster of storms north of the Milwaukee area in Ozaukee County pulsed to severe limits and generated large hail up to 3/4 inch in diameter during the early afternoon hours. A second round of severe weather was associated with several clusters or short bowing segments of lines of storms that moved west to east across southern Wisconsin during the late afternoon and evening hours. Surface temperatures in the 80s and surface dewpoints in the 60s resulted in CAPE values of 1500 to 2000 while a vorticiy maxima at 500 MB moved across Wisconsin. Veering winds allowed for the development of rotating updrafts in a couple cells that generated two weak tornadoes. Otherwise, the severe weather type was powerful downburst winds.

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 Jul 10, 2:54 AM CST, 9 hours 26 minutes earlier.

Area forecast discussion, Jul 10, 2:54 AM CST, 9 hours 26 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
354 AM CDT THU JUL 10 2008

.DISCUSSION...

TODAY-
INCREASING 850 MILLIBAR THERMAL AND MOISTURE ADVECTION TODAY. OUR
COMFORTABLE DEW POINTS OF YESTERDAY WILL BE REPLACED BY 60 PLUS DEW
POINTS. GUIDANCE POPS AND QPF ALL OVER THE PLACE...BUT ONE COMMON
THEME FROM THE MODEL SOUNDINGS ARE FOR AN UNSTABLE ATMOSPHERE TO
EVOLVE TODAY WITH CAPES EXCEEDING 2K WITH A VEERING LOW LEVEL WIND
FIELD. NOTING SOME RIGHT REAR ACTION THIS AFTERNOON AS WELL...SO
WILL HAVE A CHANCE OF STORMS FOR THIS AFTERNOON. ALSO SEEING SOME
RATHER HEFTY SVR PARAMETERS WHICH POINT TOWARDS OUR WESTERN CWA
WHICH MAY BE FOCUSED NEAR DEW POINT GRADIENT.

TONIGHT-
THE WRF20 FROM 09/12Z PLAYS OUT THE SPOTTY CONVECTION TODAY AND
LINGERS IT INTO THE EVENING HOURS...BUT REALLY FOCUSES THE STRONGER
850 MILLIBAR CONVERGENCE FURTHER NORTH IN NORTHERN WI. THIS LOOKS
REASONABLE. WILL MAINTAIN A CHANCE AS ANY CONVECTION ASSOCIATED
WITH 850 CONVERGENCE MAY ROLL SOUTHEAST ALONG 1000-500 MB
THICKNESS LINES.

FRIDAY-
LOOKS TOASTY AND MUGGY AHEAD OF COLD FRONT. WARM FRONT EXPECTED TO
BE WELL NORTH OF THE CWA. 850 MILLIBAR TEMPERATURES RISE TO NEAR
20C. WILL LEAN TOWARDS GFS MOS DEW POINTS. SOUNDINGS QUITE UNSTABLE
WITH LITTLE OR NO CAP NOTED BUT FORCING A QUESTION MARK. LEAD SHORT
WAVE FROM THE GFS LOOKS OVERDONE. WRF20 KEEPS US DRY BUT GFS SHOWS A
LOT OF CONVECTION DEVELOPING WITHIN THE WARM SECTOR DUE TO THE WAVE.
THIS WAVE SHOWS BEST DCVA TO OUR WEST THROUGH 00Z SATURDAY
ANYWAYS...SO FOR NOW WILL LEAVE DRY FORECAST INTACT.

FRIDAY NIGHT-
APPEARS THE MAIN SHOW WILL ARRIVE WITH COLD FRONT. EXPECTING A
DECENT LINE OF STORMS TO SWING THROUGH...PER SWODY2. THE LIKELY POPS
CERTAINLY LOOK GOOD.

SATURDAY-
MODELS STILL SHOW LINGERING PRECIPITATION EARLY IN THE DAY...SO LIKE
WHAT WE HAVE GOING IN THERE FOR SOME EARLY POPS ESPECIALLY IN THE
SOUTHEAST HALF OF CWA.

SUNDAY-
UPPER FLOW CYCLONIC WITH WEAK RIPPLES. SECONDARY SURFACE TROUGH NOT
OUT OF THE QUESTION EITHER. WILL MAINTAIN THE DRY LOOK. GFS NOT
LOOKING AS IMPRESSIVE WITH THE STRENGTH OF THE VORT AND THE
SOUTHWARD EXTENT OF IT. ECMWF HAS ALSO TRENDED DRY...SO WILL LEAVE
DRY FORECAST INTACT...FOR NOW ANYWAYS.

MONDAY-
LOOKS LIKE A PLEASANT DAY WITH CORE OF COLDER AIR ALOFT AND CYCLONIC
FLOW SHIFTING EAST. SURFACE HIGH PRESSURE SHOULD HELP ENSURE A DRY
AND PLEASANT DAY. 850 TEMPERATURES BEGIN TO MODERATE AFTER THE
SUNDAY COOL DOWN.

&&
10

.AVIATION...THOUGH MODELS GENERALLY KEEPING PCPN OUT OF FORECAST
AREA UNTIL AFTER 18Z...COULD SEE SOME PCPN WITH DEVELOPING WAA
ACROSS SFC DEW POINT GRADIENT DRAPED ACROSS NRN IA AND SRN WI/NRN IL
THAT WAS FOCUS FOR SCT PCPN LAST EVENING. WILL GO RIGHT UP TO
ISSUANCE TIME TO SEE IF ANY EARLY PCPN WILL REACH TAF SITES.
OTHERWISE TIMING/PROBABILITIES IN CURRENT TAFS FOR AFTN/EVE
SHRA/TSTMS LOOK REASONABLE. VFR CONDITIONS WITH POTENTIAL FOR MVFR
CIGS/VSBYS WITH CONVECTION. NAM GUIDANCE SHOWING MVFR VSBYS
OVERNIGHT AT/AFTER 09Z DUE TO POST-PCPN INCREASE IN BOUNDARY LAYER
MOISTURE...BUT WILL LEAVE OUT FOR NOW WITH GFS SHOWING STRONGER
OVERNIGHT SFC WINDS MIXING BOUNDARY LAYER.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&

Hazardous weather outlook, Jul 10, 11:56 AM CST, 24 minutes before

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
1256 PM CDT THU JUL 10 2008

WIZ046-047-051-052-056>060-062>072-111100-
MARQUETTE-GREEN LAKE-FOND DU LAC-SHEBOYGAN-SAUK-COLUMBIA-DODGE-
WASHINGTON-OZAUKEE-IOWA-DANE-JEFFERSON-WAUKESHA-MILWAUKEE-
LAFAYETTE-GREEN-ROCK-WALWORTH-RACINE-KENOSHA-
1256 PM CDT THU JUL 10 2008

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

SCATTERED THUNDERSTORMS ARE EXPECTED THIS AFTERNOON AND TONIGHT.
THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS ACROSS ALL OF
SOUTHERN WISCONSIN. LARGE HAIL AND DAMAGING WINDS ARE THE MAIN
HAZARDS.

SOME LAKES...RIVERS AND STREAMS REMAIN ABOVE FLOOD STAGE. A
PORTION OF THE ROCK RIVER IN SOUTHERN WISCONSIN CONTINUES TO
EXPERIENCE MODERATE FLOODING...WITH THE STRETCH OF THE RIVER
NEAR NEWVILLE STILL AT MAJOR FLOOD.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THERE IS A CHANCE OF THUNDERSTORMS FRIDAY EVENING...WITH
THUNDERSTORMS BECOMING LIKELY OVERNIGHT FRIDAY NIGHT. THERE IS ALSO
A SLIGHT RISK FOR SEVERE STORMS OVERNIGHT FRIDAY NIGHT ACROSS MAINLY
SOUTH CENTRAL WISCONSIN. LARGE HAIL AND DAMAGING WINDS ARE THE MAIN
HAZARDS.

THERE IS A CHANCE OF THE THUNDERSTORMS LINGERING INTO SATURDAY
MORNING.

A PORTION OF THE ROCK RIVER WILL REMAIN IN MODERATE FLOOD THROUGH
THE END OF THE WEEK...HOWEVER RIVER LEVELS WILL CONTINUE TO SLOWLY
FALL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EVENING.

LMZ643>646-111100-
SHEBOYGAN TO PORT WASHINGTON WI-
PORT WASHINGTON TO NORTH POINT LIGHT WI-
NORTH POINT LIGHT TO WIND POINT WI-
WIND POINT WI TO WINTHROP HARBOR IL-
1256 PM CDT THU JUL 10 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF LAKE MICHIGAN.

.DAY ONE...THIS AFTERNOON AND TONIGHT

SCATTERED THUNDERSTORMS ARE EXPECTED LATE THIS AFTERNOON AND
TONIGHT. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS. LARGE HAIL
AND DAMAGING WINDS ARE THE MAIN HAZARDS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

WINDS WILL APPROACH SMALL CRAFT ADVISORY CRITERIA FRIDAY AFTERNOON.

THERE IS A CHANCE OF THUNDERSTORMS FRIDAY EVENING...WITH STORMS
BECOMING LIKELY OVERNIGHT FRIDAY NIGHT.

THERE IS A CHANCE OF THE THUNDERSTORMS LINGERING INTO SATURDAY
MORNING.

WOOD
WWW.WEATHER.GOV/MKX

In the hours before

Local storm report, Jul 10, 12:06 PM CST, 14 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
106 PM CDT THU JUL 10 2008

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

0105 PM     HAIL             LOWELL                  43.34N 88.82W
07/10/2008  E0.25 INCH       DODGE              WI   TRAINED SPOTTER

            ALSO 45 MPH WINDS ESTIMATED.

&&

LAMERS/KUHLMAN

Local storm report, Jul 10, 12:09 PM CST, 11 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
109 PM CDT THU JUL 10 2008

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

0107 PM     TSTM WND GST     GERMANTOWN              43.23N 88.10W
07/10/2008  E40 MPH          WASHINGTON         WI   TRAINED SPOTTER

            ALSO PONDING OF WATER BEGINNING ON ROADWAYS.

&&

LAMERS/KUHLMAN

Local storm report, Jul 10, 12:16 PM CST, 4 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
116 PM CDT THU JUL 10 2008

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

0105 PM     HAIL             GERMANTOWN              43.23N 88.10W
07/10/2008  E0.25 INCH       WASHINGTON         WI   LAW ENFORCEMENT

            REPORTED BY GERMANTOWN POLICE DEPARTMENT.

&&

LAMERS/KUHLMAN

The radar

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

Open the radar archive at this moment

Event by event

17 thunderstorm wind, 2 tornado, 1 hail, 1 flash flood. Local standard time, as filed.

Hail, Ozaukee

When: July 10, 12:20 PM CST to 12:30 PM CST
Where: Ozaukee County, 1 mi NNW of Cedarburg to 1 mi N of Cedarburg
Measured: 0.75 in hail
Reported by: CoCoRaHS
Coordinates: 43.293, -87.988

Thunderstorm Wind, Ozaukee

When: July 10, 12:27 PM CST
Where: Ozaukee County, 1 mi SW of Saukville
Measured: 50 kt (58 mph) estimated gust
Reported by: Unknown
Coordinates: 43.370, -87.944

Tree down.

Thunderstorm Wind, Sauk

When: July 10, 3:30 PM CST to 3:55 PM CST
Where: Sauk County, La Valle to Baraboo
Measured: 56 kt (64 mph) estimated gust
Property damage: $20,000
Reported by: Law Enforcement
Coordinates: 43.580, -90.130

Powerful thunderstorm wind gusts toppled large trees and broke branches that brought down some power-lines.

Thunderstorm Wind, Columbia

When: July 10, 4:07 PM CST
Where: Columbia County, 5 mi SW of Portage
Measured: 56 kt (64 mph) estimated gust
Property damage: $10,000
Reported by: Law Enforcement
Coordinates: 43.499, -89.521

Powerful thunderstorm wind gusts toppled several large trees and broke branches that brought down some power-lines.

Thunderstorm Wind, Marquette

When: July 10, 4:12 PM CST to 4:20 PM CST
Where: Marquette County, Westfield to 6 mi SE of Glenoak
Measured: 56 kt (64 mph) estimated gust
Property damage: $40,000
Reported by: Law Enforcement
Coordinates: 43.880, -89.480

Powerful thunderstorm wind gusts toppled large trees and broke branches that brought down some power-lines in locations scattered across the county. Three trailer homes about 6 miles east-northeast of Montello were damaged as two large trees came down in the winds.

Thunderstorm Wind, Dane

When: July 10, 4:18 PM CST
Where: Dane County, Cross Plains
Measured: 56 kt (64 mph) estimated gust
Property damage: $10,000
Reported by: Law Enforcement
Coordinates: 43.120, -89.630

Powerful thunderstorm wind gusts toppled several large trees and broke branches that brought down some power-lines.

Thunderstorm Wind, Green Lake

When: July 10, 4:32 PM CST to 4:42 PM CST
Where: Green Lake County, 1 mi SW of Princeton to Green Lake
Measured: 65 kt (75 mph) estimated gust
Property damage: $20,000
Reported by: Law Enforcement
Coordinates: 43.840, -89.134

Powerful thunderstorm wind gusts toppled large trees and broke branches that brought down some power-lines. One tree fell onto a trailer near Princeton.

Tornado, Green Lake

When: July 10, 4:33 PM CST to 4:35 PM CST
Where: Green Lake County, 0.91 mi W of Dalton to 0.35 mi NE of Dalton
Rating: EF1
Path length: 1.15 mi
Path width: 50 yd
Property damage: $150,000
Reported by: Emergency Manager
Coordinates: 43.652, -89.218

A weak tornado spun up about 1/2 mile southwest of Downtown Dalton near a creek and proceeded to track east across STH 44 just northeast of the intersection of STH 44 and South Main Steet, and ultimately dissipated about 1/2 mile east-southeast of Downtown Dalton just southeast of the intersection of Fountain Lane and Belle Fountain Creek. It took the roof off of a lumberyard pole shed, took part of a roof off an office building, uprooted trees, and brought down some power-lines. The starting and ending lat/long pairs of numbers are 43.65243/-89.21794 and 43.65347/-89.19503. DI#1 (SBO), DOD 5. The winds were estimated at 93 mph. The average path width was about 50 yards.

Thunderstorm Wind, Dane

When: July 10, 4:38 PM CST
Where: Dane County, Mc Farland
Measured: 78 kt (90 mph) estimated gust
Property damage: $150,000
Reported by: Law Enforcement
Coordinates: 43.020, -89.280

Powerful thunderstorm wind gusts toppled large trees and broke branches that brought down some power-lines. In McFarland, a house was blown down, and tree debris damaged a restaurant .

Thunderstorm Wind, Dodge

When: July 10, 4:56 PM CST
Where: Dodge County, Beaver Dam
Measured: 56 kt (64 mph) estimated gust
Property damage: $10,000
Reported by: Law Enforcement
Coordinates: 43.470, -88.830

Powerful thunderstorm wind gusts toppled several large trees and broke branches that brought down some power-lines.

Thunderstorm Wind, Green

When: July 10, 4:58 PM CST
Where: Green County, 2 mi S of Albany
Measured: 56 kt (64 mph) estimated gust
Property damage: $5,000
Reported by: Law Enforcement
Coordinates: 42.671, -89.430

Powerful thunderstorm wind gusts toppled several large trees and broke branches that brought down some power-lines.

Thunderstorm Wind, Fond du Lac

When: July 10, 5:00 PM CST
Where: Fond du Lac County, Brandon
Measured: 56 kt (64 mph) estimated gust
Property damage: $5,000
Reported by: Law Enforcement
Coordinates: 43.730, -88.770

Powerful thunderstorm wind gusts toppled several large trees and broke branches that brought down some power-lines.

Tornado, Dodge

When: July 10, 5:00 PM CST to 5:02 PM CST
Where: Dodge County, 2.82 mi WSW of Waupun Arpt to 1.8 mi WSW of Waupun Arpt
Rating: EF1
Path length: 1.02 mi
Path width: 50 yd
Property damage: $20,000
Reported by: Law Enforcement
Coordinates: 43.607, -88.823

This weak tornado uprooted 9 large oak trees and damage a barn roof. It spun up just northeast of the intersection of CTH W and CTH F and moved east-northeast across STH 68 near a bend in STH 68, and dissipated just southeast of the intersection of STH 68 and Buckhorn Road. The starting and end lat/long pairs of numbers are: 43.60684/-88.82342 and 43.61147/-88.80410. DI#27 (TH), DOD3. The winds were estimated at 94 mph. The average path width was about 30 yards.

Thunderstorm Wind, Jefferson

When: July 10, 5:00 PM CST to 5:08 PM CST
Where: Jefferson County, Johnson Creek to 1 mi NW of Jefferson
Measured: 56 kt (64 mph) estimated gust
Property damage: $20,000
Reported by: Public
Coordinates: 43.080, -88.770

Powerful thunderstorm wind gusts toppled several large trees and broke branches that brought down some power-lines. Five tents were damaged at the Jefferson County Fairgrounds.

Thunderstorm Wind, Rock

When: July 10, 5:09 PM CST to 5:10 PM CST
Where: Rock County, 2 mi N of Downtown Janesville to 1 mi NE of Downtown Janesville
Measured: 65 kt (75 mph) estimated gust
Property damage: $10,000
Reported by: Public
Coordinates: 42.709, -89.020

Powerful thunderstorm wind gusts toppled several large trees and broke branches that brought down some power-lines.

Thunderstorm Wind, Walworth

When: July 10, 5:17 PM CST
Where: Walworth County, Whitewater
Measured: 56 kt (64 mph) estimated gust
Property damage: $5,000
Reported by: Law Enforcement
Coordinates: 42.830, -88.730

Powerful thunderstorm wind gusts toppled several large trees and broke branches that brought down some power-lines.

Thunderstorm Wind, Jefferson

When: July 10, 5:22 PM CST
Where: Jefferson County, 3.8 mi SSE of Sullivan
Measured: 50 kt (58 mph) measured gust
Reported by: NWS Employee
Coordinates: 42.969, -88.551

Powerful thunderstorm wind gust measured at NWS office.

Thunderstorm Wind, Walworth

When: July 10, 5:25 PM CST to 5:30 PM CST
Where: Walworth County, Darien to Williams Bay
Measured: 65 kt (75 mph) estimated gust
Property damage: $100,000
Reported by: Law Enforcement
Coordinates: 42.600, -88.700

Powerful thunderstorm wind gusts toppled several large trees and broke branches that brought down some power-lines. At least 6 homes sustained damage due to tree debris in the Walworth to Williams Bay area.

Thunderstorm Wind, Waukesha

When: July 10, 5:32 PM CST
Where: Waukesha County, Eagle to Mukwonago
Measured: 56 kt (64 mph) estimated gust
Property damage: $10,000
Reported by: Law Enforcement
Coordinates: 42.880, -88.470

Powerful thunderstorm wind gusts toppled several large trees and broke branches that brought down some power-lines.

Thunderstorm Wind, Racine

When: July 10, 5:44 PM CST
Where: Racine County, 1.5 mi WNW of Tichigan
Measured: 56 kt (64 mph) estimated gust
Property damage: $5,000
Reported by: Law Enforcement
Coordinates: 42.838, -88.247

Powerful thunderstorm wind gusts toppled several large trees and broke branches that brought down some power-lines.

Flash Flood, Lafayette

When: July 10, 6:00 PM CST to 7:00 PM CST
Where: Lafayette County, 2 mi NE of Benton to 2 mi NW of Benton
Cause: Heavy Rain
Property damage: $10,000
Reported by: Law Enforcement
Coordinates: 42.590, -90.352

Heavy rains of 2 to 3 inches within 1 to 1.5 hours resulted in flash flooding in and around Benton as water depths reached 3 feet on some roads. Some gravel shoulder washouts were noted.

What these are

Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
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.
Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.

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

The same day elsewhere

Every storm in Wisconsin in 2008 Every state in 2008 This day in weather history The tornado archive for Wisconsin, 2008 Warnings in Wisconsin, July 2008

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: 120174, 120180, 120182, 120184, 120196, 120186, 120203, 120211, 120188, 120216, 120224, 120219, 120223, 120227, 120225, 120233, 120229, 120236, 120234, 120240, 120246.