EF1 tornado, Ulmer, Montana, July 8, 2013

1. EF065 to 85 mph

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

2. EF186 to 110 mphthis tornado

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

3. 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.

4. 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.

5. EF4166 to 200 mph

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

6. 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.

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.

Rating

EF1

Date

July 8, 2013

Touchdown

6:54 PM MDT (00:54 UTC)

Lifted

7:10 PM MDT (01:10 UTC)

On the ground

16 minutes

Path length

0.6 miles (0.9 km)

Path width

100 yards (91 m)

Deaths

0

Injuries

0

County

Custer County

Touchdown point

46.242, -105.759

Lift-off point

46.242, -105.759

Record number

1307081854-01

A severe thunderstorm, that originated in the Lewistown area, which had a history of damaging wind and hail, produced a couple of weak tornadoes in the Melstone and Miles City areas during the late afternoon and early evening hours of July 8th.

A severe thunderstorm that originated in the Lewistown area strengthened even more by the time it reached Custer County. A bow echo structure moved rapidly through the Miles City area. A damage assessment team indicated a very strong outflow in the 75-110 mph range occurred due to a descending inflow jet that produced a short-lived spin-up tornado. This brief touchdown of an EF1 tornado was eventually outrun by the storm outflow as it moved eastward. ||Areal coverage was about one square mile along MT State Road 332 about 13 miles south of Miles City. Debris was thrown several hundred yards from the point of origin. Several structures were impacted with parts of several roofs blown off and the side of one house blown off. Dozens of large trees 12-16 inches in diameter were uprooted and large tree limbs were thrown long distances. In addition, 12 power poles were knocked down, an irrigation pipe system was thrown several hundred feet and a camper was overturned. Other impacts included tree limbs blocking roads, power outages, campers at 12 Mile Dam (no known injuries), and major structural damage to homes, barns, and garages.

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

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.

The county was under a severe thunderstorm watch, issued at 22:01 UTC and running to 03:18 UTC.

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 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 19:59 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 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.

The Billings radar (KBLX), 224 km away, was scanning. The volume nearest the touchdown began at 00:52 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.

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

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

The live radar over the trackEvery 2013 tornado in MontanaEvery tornado in Montana since 1950Warnings in force in Montana nowThe forecast where you are

2 more were confirmed in the United States that day.

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.

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