Tornadoes · United States · Wisconsin · 2005

F0 tornado, Neenah, Wisconsin, August 18, 2005

This F0 tornado ran 4.0 miles across Winnebago County on August 18, 2005, touching down at 7:40 PM CDT and reaching 50 yards wide. It killed nobody, and did $1,000 of property damage.

The rating scale

Tracks are drawn in the color of the rating. The Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  1. F040 to 72 mphthis tornado

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. F173 to 112 mph

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. F2113 to 157 mph

    Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.

  4. F3158 to 206 mph

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. F4207 to 260 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. F5261 to 318 mph

    Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.

  7. Unrated

    The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

The record

Rating
F0
Date
August 18, 2005
Touchdown
7:40 PM CDT (00:40 UTC)
Path length
4.0 miles (6.4 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
Property damage
$1,000
County
Winnebago County
Touchdown point
44.180, -88.530
Lift-off point
44.220, -88.480
Record number
1115

What the Weather Service recorded

A surface low pressure system, with a warm front extending to the east, moved from west to east across Wisconsin during the evening. The surface system combined with an unseasonably strong upper level disturbance and a very unstable atmosphere to produce thunderstorms. Five tornadoes developed from these storms in east central Wisconsin. Each tornado fell into the "weak" category and was on the ground for less than ten minutes.The first tornado in the area touched down southwest of Wautoma (Waushara co.), snapping off and uprooting numerous trees, and causing damage to a few buildings and some farm equipment before dissipating. A tree fell onto a large pole building, causing major damage to one of its sides, and the porch at a residence was destroyed by a fallen tree limb. A portion of the metal roof of a barn was torn from it and thrown about 200 feet, an irrigation system was damaged and a home suffered minor shingle damage.The second tornado touched down southwest of New London (Waupaca co.), snapping off large trees and damaging a few buildings along its path. It shifted a large barn, destroyed a small metal shed and threw it about a quarter mile, and overturned an outbuilding and threw it 30 to 40 feet into a stand of trees.The third tornado touched down west of Neenah (Winnebago co.), downing trees, stripping some siding from a home and destroying a corn crib before dissipating.The fourth tornado touched down northeast of Wrightstown (Brown co.) and downed or snapped about 75 trees and damaged or destroyed several structures along its path. Two wooden garages were destroyed and debris scattered for several hundred feet. The walls of a house that was under construction were blown down, part of the steel roof of a commercial building was pulled from it, and a heavy wooden bench was picked up from the front porch of a house and thrown several hundred feet away behind the house.The last of the tornadoes touched down southwest of Manitowoc (Manitowoc co.) and caused considerable damage to a farm and snapped or uprooted about 50 large trees before it dissipated. Several hay wagons and trailers were overturned. A concrete silo was destroyed and another damaged, and the roof of a barn sustained extensive damage. Parts of the barn and silo were found in trees a third of a mile away.The tornadoes were part of a record tornado outbreak in Wisconsin.The storms also produced torrential rains that caused some minor street flooding in parts of Brown, Outagamie and Manitowoc counties.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

Issued (UTC)ExpiredProductOffice
00:48 UTC01:13 UTCTornado WarningGRB

Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.

The forecast that day

The Storm Prediction Center had this point in a Slight Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 19:57 UTC.

SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.

The air that afternoon

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

Green Bay/Straub, WI (KGRB), 00:00Z

0.7 hours before the tornado, 45 km from the path. August 19, 2005.

Skew-T log-pSkew-T log-p diagram, Green Bay/Straub, WI at 00:00Z on 2005-08-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 7 joules per kilogram, CIN -105, lifted condensation level 832 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Green Bay/Straub, WI at 00:00Z on 2005-08-19The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 64 square meters per square second, 0 to 6 km bulk shear 18 knots.1939Sfc1 km3 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
7 J/kg
Mixed-layer CIN
-105 J/kg
Surface CAPE
275 J/kg
Mixed-layer LCL
832 m above ground
0-6 km bulk shear
18 kt
0-1 km bulk shear
9 kt
0-1 km storm-relative helicity
64 m²/s²
0-3 km storm-relative helicity
161 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.2 K/km

Open this sounding in Storm Lab

Green Bay/Straub, WI (KGRB), 12:00Z

11.3 hours after it, 45 km from the path. August 19, 2005.

Skew-T log-pSkew-T log-p diagram, Green Bay/Straub, WI at 12:00Z on 2005-08-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -62525, lifted condensation level 562 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Green Bay/Straub, WI at 12:00Z on 2005-08-19The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity -17 square meters per square second, 0 to 6 km bulk shear 27 knots.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
-62525 J/kg
Surface CAPE
9 J/kg
Mixed-layer LCL
562 m above ground
0-6 km bulk shear
27 kt
0-1 km bulk shear
8 kt
0-1 km storm-relative helicity
-17 m²/s²
0-3 km storm-relative helicity
27 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.4 K/km

Open this sounding in Storm Lab

The radar

The Green Bay radar (KGRB), 46 km away, was scanning. The volume nearest the touchdown began at 00:38 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

What was reported nearby

Local storm reports within 60 km of the path, in the three hours either side.

Time (UTC)ReportWhereCountyRemark
00:42 UTCTORNADO2 Sw New LondonWaupaca, WIPOSSIBLE BRIEF TORNADO TOUCHDOWN SOUTHWEST OF NEW LONDON
00:42 UTCTORNADO3 Sw New LondonWaupaca, WIBRIEF TORNADO TOUCHDOWN SOUTHWEST OF NEW LONDON NEAR HUNTLEY ROAD AND COUNTY HWY W. 12 INCH DIAMETER TREES SNAPPED OFF AND A SHED DESTROYED. WITNESSES SAW THE TORNADO TOUCHDOWN.
00:42 UTCTORNADO3 Sw New LondonWaupaca, WITORNADO TOUCHDOWN SOUTHWEST OF NEW LONDON NEAR HUNTLEY ROAD AND COUNTY HWY W. 12 INCH DIAMETER TREES SNAPPED OFF AND A SHED DESTROYED. SEVERAL WITNESSES SAW THE TORNADO TOUCHDOWN.
00:43 UTCTORNADO2 E LarsenWinnebago, WIPOSSIBLE BRIEF TORNADO TOUCHDOWN NEAR LARSEN
00:43 UTCTORNADO3 E LarsenWinnebago, WIBRIEF TORNADO TOUCHDOWN EAST OF LARSEN. CORN STORAGE STRUCTURE, HOUSE SIDING AND UTILITY LINES DAMAGED. DAMAGE OCCURRED NEAR OLD HWY 45 AND OAKWOOD RD.
01:46 UTCTORNADO7 Ene WrightstownBrown, WI3 GARAGES DEMOLISHED, HOUSE UNDER CONSTRUCTION DEMOLISHED, SIDING AND SHINGLE DAMAGE, TREES DOWN. DAMAGE OCCURRED ON COUNTY HWY PP AND SHIRLEY ROAD.
01:57 UTCFLOODDe PereBrown, WISTREET FLOODING ON LOST DAUPHIN RD NEAR INTERSECTIONS OF JAN LANE AND STEVENS RD...TO DEPTH OF 7 INCHES.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the trackEvery 2005 tornado in WisconsinEvery tornado in Wisconsin since 1950Warnings in force in Wisconsin nowThe forecast where you are

The other tornadoes of August 18, 2005

27 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 1812:50 PM CDTF0Mower, MN0.120$10,000
August 182:18 PM CDTF0Trempealeau, WI0.125$2,000
August 183:46 PM CDTF1Vernon, WI1.2251$150,000
August 184:05 PM CDTF2Vernon, WI20.0403$3.3 million
August 184:40 PM CDTF1Richland, WI4.055$200,000
August 184:54 PM CDTF1Monroe, WI10.025$140,000
August 184:55 PM CDTF0Iowa, WI0.125
August 185:18 PM CDTF1Iowa, WI6.5100$20,000
August 185:30 PM CDTF1Sauk, WI1.975$2,000
August 185:33 PM CDTF2Sauk, WI14.5200$610,000
August 185:39 PM CDTF1Adams, WI0.830$10,000
August 186:00 PM CDTF0Sauk, WI1.075$10,000
August 186:08 PM CDTF1Marquette, WI5.5100$100,000
August 186:10 PM CDTF0Columbia, WI0.125
August 186:15 PM CDTF3Dane, WI18.6600123$34 million
August 186:17 PM CDTF0Dane, WI2.030
August 186:32 PM CDTF0Waushara, WI2.080$10,000
August 187:10 PM CDTF1Dane, WI1.6100$70,000
August 187:15 PM CDTF0Jefferson, WI0.550$50,000
August 187:20 PM CDTF1Jefferson, WI0.750$30,000
August 187:27 PM CDTF1Jefferson, WI1.250$30,000
August 187:37 PM CDTF1Jefferson, WI1.450$350,000
August 187:38 PM CDTF0Waupaca, WI1.240$1,000
August 187:44 PM CDTF1Jefferson, WI3.075$20,000
August 187:45 PM CDTF0Jefferson, WI0.250$10,000
August 188:45 PM CDTF1Brown, WI1.0100$10,000
August 189:35 PM CDTF1Manitowoc, WI1.5100$10,000

What this means

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

Sources

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.