Alert archive / South Dakota / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 164, NWS Sioux Falls, SD

August 10, 2020Charles Mix County, Douglas County, Gregory County, South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 10, 2020, 5:25 AM CDT for Charles Mix County, Douglas County, Gregory County, South Dakota. It was in force for 50 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Aug 10, 2020, 5:25 AM CDT (10:25 UTC)
Expired: Aug 10, 2020, 6:15 AM CDT
In force: 50 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Hail: 1.25 in
Wind: 70.0 mph

Counties Charles Mix County, SD, Douglas County, SD, Gregory County, SD

The radar

The Sioux Falls radar (KFSD), 164 km from the middle of the area, began a volume at 10:27 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 10.4 hours before the alert went out and 184 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

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.

Mixed-layer CAPE: 93 J/kg
Mixed-layer CIN: -321 J/kg
Mixed-layer LCL: 1751 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: -60 m²/s²
0-3 km storm-relative helicity: 174 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -5.3

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Sioux Falls, SD wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 10, 2:58 AM CDT, 2 hours 27 minutes earlier.

Area forecast discussion, Aug 10, 2:58 AM CDT, 2 hours 27 minutes before

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Hazardous weather outlook, Aug 10, 3:18 AM CDT, 2 hours 7 minutes before

Hazardous Weather Outlook
National Weather Service Sioux Falls SD
318 AM CDT Mon Aug 10 2020

IAZ001>003-012>014-020>022-031-032-MNZ071-072-080-081-089-090-097-
098-NEZ013-014-SDZ038>040-050-052>071-110830-
Lyon-Osceola-Dickinson-Sioux-O'Brien-Clay-Plymouth-Cherokee-
Buena Vista-Woodbury-Ida-Lincoln-Murray-Cottonwood-Nobles-Jackson-
Pipestone-Rock-Dixon-Dakota-Beadle-Kingsbury-Brookings-Gregory-
Jerauld-Sanborn-Miner-Lake-Moody-Brule-Aurora-Davison-Hanson-
McCook-Minnehaha-Charles Mix-Douglas-Hutchinson-Turner-Bon Homme-
Yankton-Union-
318 AM CDT Mon Aug 10 2020

This Hazardous Weather Outlook is for portions of northwest Iowa,
west central Iowa, southwest Minnesota, northeast Nebraska,
central South Dakota, east central South Dakota, south central
South Dakota, and southeast South Dakota.

.DAY ONE...Today and Tonight

Scattered thunderstorms will be possible though mid morning,
mainly from the Interstate 90 corridor and southward. A few of
these storms could become strong to severe, with hail to the size
of half dollars and wind gusts to 60 mph.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will be possible through 10 am.

In the hours before

Local storm report, Aug 10, 4:47 AM CDT, 38 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
447 AM CDT MON AUG 10 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0250 AM     HAIL             PLANKINTON              43.71N 98.49W
08/10/2020  M1.75 INCH       AURORA             SD   PUBLIC

&&

Local storm report, Aug 10, 4:51 AM CDT, 34 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
451 AM CDT MON AUG 10 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0433 AM     HAIL             1 SW GREGORY            43.23N 99.43W
08/10/2020  M2.00 INCH       GREGORY            SD   PUBLIC

&&

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 10, 2:47 AM CDT	Severe Thunderstorm Warning	FSD	Aurora, Davison	43 min
Aug 10, 3:23 AM CDT	Severe Thunderstorm Warning	FSD	Davison, Hanson, Miner, Sanborn	34 min
Aug 10, 4:22 AM CDT	Severe Thunderstorm Warning	FSD	Gregory	38 min
Aug 10, 4:27 AM CDT	Severe Thunderstorm Warning	FSD	McCook, Minnehaha	48 min
Aug 10, 4:49 AM CDT	Severe Thunderstorm Warning	FSD	Charles Mix, Gregory	41 min
Aug 10, 5:49 AM CDT	Severe Thunderstorm Warning	FSD	Bon Homme, Charles Mix, Douglas, Hutchinson	56 min
Aug 10, 6:32 AM CDT	Severe Thunderstorm Warning	FSD	Bon Homme, Clay, Hutchinson, Turner, Yankton	58 min
Aug 10, 5:51 AM CDT	Severe Thunderstorm Warning	FSD	Lyon, Osceola	39 min
Aug 10, 8:49 AM CDT	Severe Thunderstorm Warning	FSD	Ida, Woodbury	41 min
Aug 10, 9:26 AM CDT	Severe Thunderstorm Warning	FSD	Buena Vista, Ida	34 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 2020 Every severe thunderstorm warning in 2020

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.