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Public Information Statement...UPDATED
National Weather Service Aberdeen SD
700 PM CDT Sun Sep 1 2024

...NWS Damage Survey for 8/28/24 Tornado Event Update #3...

Update...the damage survey has been updated based on the
collection of multiple data sources. Data from the original ground
survey broke the path into three separate tracks. However, with
the review of drone and high-resolution satellite imagery, there
is evidence of a continuous track from beginning to end. The event
was very complicated with many smaller tornadoes/vortices
embedded within, or rotating around, the main circulation. This
resulted in sporadic, intense areas of multi-directional tornado
damage, as well as areas of very broad uniform damage. Experts
were also consulted to determine wind speeds based on the electric
transmission tower damage indicators. Path length, width, and
peak winds were all increased with this update.

.Southwest Mound City Tornado #1...

Rating:                 EF2
Estimated Peak Wind:    130 mph
Path Length /statute/:  5.42 miles
Path Width /maximum/:   200 yards
Fatalities:             0
Injuries:               0

Start Date:             08/28/2024
Start Time:             07:50 PM CDT
Start Location:         8 WSW Mound City / Campbell County / SD
Start Lat/Lon:          45.6837 / -100.2431

End Date:               08/28/2024
End Time:               08:20 PM CDT
End Location:           6 SW Mound City / Campbell County / SD
End Lat/Lon:            45.6695 / -100.159

Survey Summary:
Around 7:50 pm CDT, the tornado touched down on the west side of
SDHWY 1804, just north of 118th St. Within a few minutes of being
on the ground, it tracked east and crossed SDHWY 1804, tossing
hay bales in its path. Between 8:00-8:05 pm CDT, the tornado
continued in a more southeast direction, crossing 118th St and
encountering an electric transmission line, resulting in the
collapse of three electrical transmission towers. The tornado
then continued east-southeast toward 119th St, where it
encountered a farmstead. At this location, multiple trees were
broken, snapped, and uprooted. One small shed was lifted, another
had its walls collapse, and a machine shed had its doors blown
out. The main house lost windows, and a tractor lost its doors
facing east and west, although the front and back windshields
remained intact. Additionally, a trailer was rolled onto the
road, and other farm implements were destroyed or moved. Between
8:05-8:10 pm CDT, the tornado would cross to the south of 119th
St, flipping a haybine to the west and through a fence. The main
tornadic circulation broadened and tracked east, becoming nearly
stationary at times as it traversed over cropland between 299th
and 301st Ave. Despite this, many smaller tornadic vortices were
noted on video accounts, and the track is evident in drone and
high-resolution satellite imagery. Toward the end of the tornado
cycle, between roughly 8:15-8:20 pm CDT, it intensified once
again, becoming narrower and tracking from southwest to
northeast, crossing 119th St between 301st and 302nd Ave. The
track was clearly seen through a corn crop before lifting. Around
this same time, a distinct smaller tornado/vortex damaged a
farmstead. At this location, a tree was uprooted, a silo was
dented, and two shop buildings lost roof panels and doors.
Additionally, a travel trailer was rolled 100 feet across 119th
St, with debris tossed from north-northeast to south-southwest
into a cornfield. Two other smaller tornadic circulations were
also noted in the corn crop just west of the intersection of
302nd Ave and 119th St.

.Southeast Mound City Tornado #2...

Rating:                 EFU
Estimated Peak Wind:    N/A
Path Length /statute/:  N/A
Path Width /maximum/:   N/A
Fatalities:             0
Injuries:               0

Start Date:             08/28/2024
Start Time:             08:50 PM CDT
Start Location:         3.5 SE Mound City / Campbell County / SD
Start Lat/Lon:          45.71 / -100.00

End Date:               08/28/2024
End Time:               08:52 PM CDT
End Location:           3.5 SE Mound City / Campbell County / SD
End Lat/Lon:            45.71 / -100.00

Survey Summary:
Photo evidence of a tornado touchdown roughly 3.5 miles southeast
of Mound City continues to be investigated.

&&

EF Scale: The Enhanced Fujita Scale classifies tornadoes into the
following categories:

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

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


$$