Updraft® - Minnesota Weather News

Confirmed EF-1 tornado with 105 mph winds near Watertown

The Twin Cities National Weather Service confirms an EF-1 tornado packing 105 mph winds touched down for 3 minutes last night near Watertown in Carver County. Debris signatures were detected in the air on the Chanhassen Doppler as the tornado tore through western Carver County.

717 watertown tornado

The details from the NWS post storm survey conducted Saturday morning.

PUBLIC INFORMATION STATEMENT

NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN, MN

925 AM CDT SAT JUL 18 2015

...NWS DAMAGE SURVEY FOR 07/17/2015 TORNADO EVENT...

...EF-1 TORNADO OCCURRED WEST OF WATERTOWN IN CARVER COUNTY MINNESOTA...

A LINE OF SEVERE THUNDERSTORMS TRACKED EAST ACROSS MOST OF CENTRAL MINNESOTA DURING THE LATE EVENING OF JULY 17TH. A TORNADO DEVELOPED ON THE LEADING EDGE OF THIS LINE AND IMPACTED PORTIONS OF NORTHERN CARVER COUNTY. NWS DUAL POL RADAR OBSERVED TORNADIC DEBRIS...AND A DAMAGE SURVEY CONFIRMED A 4.3 MILE LONG TORNADO.

RATING: EF-1

ESTIMATED PEAK WIND: 105 MPH

PATH LENGTH /STATUTE/: 4.3 MILES

PATH WIDTH /MAXIMUM/: 500 YARDS

FATALITIES: 0

INJURIES: 0

START DATE: JULY 17 2015

START TIME: 1158 PM CDT

START LOCATION: HIGHWAY 33 AND 30TH STREET... 3N HOLLYWOOD

START LAT/LON: 44.9488/-93.9715

END DATE: JULY 18 2015

END TIME: 1202 AM CDT

END LOCATION: NORTH OF ROSE AVENUE AND COUNTY 122... 2WSW

WATERTOWN

END_LAT/LON: 44.9532/-93.8846

MPR News reporter Brandt Willimas captured this damage near Watertown.

KARE11 News has more on Carver County damage from the air.

Probable "Gustnado"

This was an unusual type of tornado called a Gust Front Tornado or Gustnado.

Gustnadoes form on the leading edge of  squall line downbursts. They spin up briefly in the wake flow of severe gust front winds on the storm's leading edge. They are usually brief, and very difficult to forecast in advance. That's why there was no tornado watch, and no tornado warnings with the storm line in Minnesota prior to the event.

800px-Gustnado_in_Jefferson_County,_Kansas_on_April_3,_2011
"Gustnado in Jefferson County, Kansas on April 3, 2011" by Jefferson County Emergency Management - http://www.crh.noaa.gov/images/top/040411Gustnado.jpg. Licensed under Public Domain via Wikimedia Commons - https://commons.wiki

The Twin Cities NWS did an excellent job issuing severe thunderstorms warnings for this event. The sudden tornado warning was also issued in as timely a fashion as possible, as the radar operators recognized the tornado vortex signature on Doppler and the benchmarks of debris in the air.

There are also scattered tree damage reports across the metro.

Winds gusted as high as to 70 mph.

Wind gust reports from storm of July 17-18, 2015

Location Miles per hour Time

New Brighton 70 12:56 a.m

Lakeville 70 12:41 a.m

Eau Claire, Wis. 70 1:54 a.m

Richfield 67 12:40 a.m

Montevideo 63 10:13 p.m

Benson 61 10:14 p.m.

MSP Airport 60 1:33 a.m

Excelsior 55 1:22 a.m

Rochester 47 1:54 a.m

Source: National Weather Service