Tornadoes · United States · Wisconsin · 2015

EF0 tornado, Germantown to Freistadt, Wisconsin, August 10, 2015

Name: EF0 tornado, Germantown to Freistadt, Wisconsin, August 10, 2015
Start: 2015-08-10T19:12:00.000Z
End: 2015-08-10T19:15:00.000Z
Location: Germantown to Freistadt, Wisconsin

From Germantown to Freistadt, this EF0 tornado ran 1.0 miles across Washington and Ozaukee counties on August 10, 2015, touching down at 2:12 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 Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

EF065 to 85 mphthis tornado
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
EF2111 to 135 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.
EF3136 to 165 mph
Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
EF5over 200 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.
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: EF0
Date: August 10, 2015
Touchdown: 2:12 PM CDT (19:12 UTC)
Lifted: 2:15 PM CDT (19:15 UTC)
On the ground: 3 minutes
Path length: 1.0 miles (1.6 km)
Path width: 50 yards (46 m)
Deaths: 0
Injuries: 0
Property damage: $1,000
Counties: Washington and Ozaukee counties
Touchdown point: 43.245, -88.080
Lift-off point: 43.246, -88.060
Record number: 1508101312-01

The damage survey

5 damage points were recorded along this path by NWS MKX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 84 mph.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

What the Weather Service recorded

The passage of a weak cold front within an unstable airmass resulted in scattered thunderstorms. A few thunderstorms became severe with damaging winds, large hail, and one brief and weak tornado.

A very sporadic damage path of small branches and twigs down.

A sporadic damage path with one uprooted tree and small branches and twigs.

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.

Issued (UTC)	Expired	Product	Office
16:27 UTC	16:55 UTC	Severe Thunderstorm Warning	MKX

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 General Thunderstorms Risk. The outlook in force was issued at 16:27 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), 12:00Z

7.2 hours before the tornado, 137 km from the path. August 10, 2015.

Skew-T log-p

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.

Hodograph

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: 1097 J/kg
Mixed-layer CIN: -16 J/kg
Surface CAPE: 628 J/kg
Mixed-layer LCL: 651 m above ground
0-6 km bulk shear: 29 kt
0-1 km bulk shear: 8 kt
0-1 km storm-relative helicity: 7 m²/s²
0-3 km storm-relative helicity: 15 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), 00:00Z

4.8 hours after it, 137 km from the path. August 11, 2015.

Skew-T log-p

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.

Hodograph

Mixed-layer CAPE: 9 J/kg
Mixed-layer CIN: -10 J/kg
Surface CAPE: 1175 J/kg
Mixed-layer LCL: 1874 m above ground
0-6 km bulk shear: 28 kt
0-1 km bulk shear: 11 kt
0-1 km storm-relative helicity: 8 m²/s²
0-3 km storm-relative helicity: 30 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0
0-3 km lapse rate: 7.5 K/km

Open this sounding in Storm Lab

The radar

The Milwaukee radar (KMKX), 50 km away, was scanning. The volume nearest the touchdown began at 19:12 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)	Report	Where	County	Remark
16:25 UTC	HAIL 1.75	2 Nw Germantown	Washington, WI	REPORTED ATTHE PUBLIC WORKS DEPT
16:25 UTC	HAIL 1.75	2 Nw Germantown	Washington, WI	REPORTED AT THE PUBLIC WORK FACILITY
16:28 UTC	HAIL 0.5	3 Ese Germantown	Ozaukee, WI
17:15 UTC	HAIL 0.75	Milwaukee Hoan Bridge	Milwaukee, WI
17:15 UTC	HAIL 1	2 Sse Milwaukee	Milwaukee, WI	A FEW BLOCKS FROM SOUTH SHORE PARK IN BAY VIEW
17:17 UTC	TSTM WND GST 44	Milwaukee International	Milwaukee, WI
18:41 UTC	HEAVY RAIN 1.1	1 N Milwaukee Internati	Milwaukee, WI	1.10 INCHES OF RAIN IN 30 MIN PERIOD
19:12 UTC	TORNADO	3 Ne Germantown	Washington, WI	VIDEO...LAW ENFORECMENT AND WITNESSES PRELIMINARILY SUPPORT AN EF0 TORNADO ABOUT 1/2 MILE EAST OF PLEASANT VIEW DR NORTHEAST OF GERMANTOWN. NO DAMAGE OR INJURIES WERE REPORTED. VERY SMALL IN SCALE AND LASTED JUST A FEW M

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

This ground now

The live radar over the track Every 2015 tornado in Wisconsin Every tornado in Wisconsin since 1950 Warnings in force in Wisconsin now The forecast where you are

The other tornadoes of August 10, 2015

1 more were confirmed in the United States that day.

Date	Time	Rating	Where	Path (mi)	Width (yd)	Deaths	Injuries	Damage
August 10	9:45 PM EDT	EF0	Butler, PA	0.6	60			$25,000

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.