Alert archive / South Dakota / Excessive Heat Warnings in 2023

Excessive Heat Warning 3, NWS Sioux Falls, SD

August 20, 202324 counties in South Dakota; 11 counties in Iowa; 8 counties in Minnesota

NWS Sioux Falls, SD issued this excessive heat warning at Aug 20, 2023, 2:41 PM CDT for 24 counties in South Dakota; 11 counties in Iowa; 8 counties in Minnesota. It took effect at Aug 21, 2023, 12:00 PM CDT. It was in force for 3 days. 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 20, 2023, 2:41 PM CDT (19:41 UTC)
In effect from: Aug 21, 2023, 12:00 PM CDT
Expired: Aug 24, 2023, 7:00 PM CDT
In force: 3 days
Issued by: NWS Sioux Falls, SD

All 43 counties

Buena Vista County, IA, Cherokee County, IA, Clay County, IA, Dickinson County, IA, Ida County, IA, Lyon County, IA, O'Brien County, IA, Osceola County, IA, Plymouth County, IA, Sioux County, IA, Woodbury County, IA, Cottonwood County, MN, Jackson County, MN, Lincoln County, MN, Lyon County, MN, Murray County, MN, Nobles County, MN, Pipestone County, MN, Rock County, MN, Aurora County, SD, Beadle County, SD, Bon Homme County, SD, Brookings County, SD, Brule County, SD, Charles Mix County, SD, Clay County, SD, Davison County, SD, Douglas County, SD, Gregory County, SD, Hanson County, SD, Hutchinson County, SD, Jerauld County, SD, Kingsbury County, SD, Lake County, SD, Lincoln County, SD, McCook County, SD, Miner County, SD, Minnehaha County, SD, Moody County, SD, Sanborn County, SD, Turner County, SD, Union County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 12 km from the middle of the area, began a volume at 19:44 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

Minneapolis, MN (KMPX), launched 12:00Z, 7.7 hours before the alert went out and 298 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2544 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: -75 m²/s²
0-3 km storm-relative helicity: -20 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this excessive heat 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 excessive heat warning went out at Aug 20, 12:44 PM CDT, 1 hour 57 minutes earlier.

Area forecast discussion, Aug 20, 12:44 PM CDT, 1 hour 57 minutes before

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Hazardous weather outlook, Aug 20, 3:49 AM CDT, 10 hours 52 minutes before

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      <div class="status" id="status">Temporary Notice</div>
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        The site you requested is temporarily down for maintenance or an unexpected outage.
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The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 20, 2:41 PM CDT	Heat Advisory	FSD	Aurora, Beadle, Brookings, Brule, Jerauld, Kingsbury and 2 more	20 hr

Nearby

Excessive Heat Warnings in South Dakota, 2023 Excessive Heat Warnings in Iowa, 2023 Excessive Heat Warnings in Minnesota, 2023 Every excessive heat warning in 2023

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.