The Cheyenne Office of the National Weather Service has released a preliminary report on a pair of tornadoes that touched down near Chugwater on July 4th.

The agency posted this report on its website over the weekend:

Overview

During the  afternoon of Independence Day 2019, a supercell thunderstorm produced two tornadoes in southern Platte County near Chugwater Wyoming. The tornadoes were observed by multiple storm chasers and law enforcement officials 5 to 10 miles south and west of Chugwater near Interstate 25. The tornadoes occurred over mostly open grassland. A NWS survey team found no damage and the tornadoes were rated EF-U for unknown. 


 

Tornado #1

DateJuly 4th, 2019
Time (local)4:46 pm
EF RatingEF-Unknown
Est. Peak WindUnknown
Injuries/Deaths0
Location:13 miles SW Chugwater

 

 

Tornado #2

DateJuly 4th, 2019
Time (local)5:16-5:30 pm
EF RatingEF-Unknown
Est. Peak WindUnknown
Injuries/Deaths0
Location:5 miles SW Chugwater

 

 

 

000
NOUS45 KCYS 060002
PNSCYS
NEZ002-003-019>021-054-055-095-096-WYZ101>119-061215-

Public Information Statement
National Weather Service Cheyenne, WY
602 PM MDT Fri Jul 5 2019

...NWS DAMAGE SURVEY FOR 07/04/2019 CHUGWATER TORNADO
EVENTS...

A supercell thunderstorm first developed over far-east
central Albany County near 3:45pm MDT. This storm moved
east to east-southeast into Platte County near 4:15pm MDT
with increasing signs of low-level rotation per KCYS radar.
The first Tornado Warning was issued at 4:32pm MDT with a
report of a brief tornado touchdown by the Chugwater Fire
Chief at 4:46pm MDT over rural ranch land and BLM Public
Lands.

The storm continued east-southeast with weak low-level
rotation and supportive reflectivity structure. A second
Tornado Warning was issued at 4:57pm MDT. Numerous reports
of funnels from chasers and storm spotters were received
just after 5pm MDT. Much stronger low-level rotation developed
near 5:14pm MDT via KCYS radar with confirmed tornado touchdown
occurring at 5:15pm MDT. The touchdown occurred 3 miles west of
Interstate 25 west of mile marker 49. The cone tornado was
observed on the ground via live-stream, pictures, and video
through numerous social media channels. Tornado remained
west of Interstate 25 through the entirety of its life cycle
as it roped out about 1 mile west of the interstate over open
ranch land. Time of dissipation is near 5:30pm MDT. Despite
extensive investigation along county roads, no damage targets
were able to be identified in the open ranch land and thus
an unknown EF rating is assigned for both tornado events.

.Chugwater, WY Tornado Brief Tornado Touchdown #1...

Rating:                 EF-Unknown
Estimated peak wind:    Unknown mph
Path length /Statute/:  0 miles
Path width /Maximum/:   Unknown yards
Fatalities:             None
Injuries:               None

Start date:             7/4/2019
Start time:             4:46PM MDT
Start location:         13SW Chugwater, WY - Platte County
Start Lat/Lon:          41.6929, -105.0926

End date:               07/04/2019
End time:               4:46PM MDT
End location:           13SW Chugwater, WY - Platte County
End_lat/lon:            41.6929, -105.0926

.Chugwater, WY Tornado Tornado #2...

Rating:                 EF-Unknown
Estimated peak wind:    Unknown mph
Path length /Statute/:  2 miles
Path width /Maximum/:   200 yards
Fatalities:             None
Injuries:               None

Start date:             7/4/2019
Start time:             5:16PM MDT
Start location:         5SW Chugwater, WY - Platte County
Start Lat/Lon:          41.6833, -104.8932

End date:               07/04/2019
End time:               5:30PM MDT
End location:           5SSW Chugwater, WY - Platte County
End_lat/lon:            41.6800/-104.8541

EF Scale: The Enhanced Fujita Scale Classifies Tornadoes into
the following categories.

EF0...Weak......65 to 85 mph
EF1...Weak......86 to 110 mph
EF2...Strong....111 to 135 mph
EF3...Strong....136 to 165 mph
EF4...Violent...166 To 200 mph
EF5...Violent...>200 mph

NOTE:
The information in this statement is PRELIMINARY and subject to
change pending final review of the events and publication in
NWS Storm Data.

$$

Allen/Worley