Alert archive / Iowa / Excessive Heat Warnings in 2020

Excessive Heat Warning 1, NWS Sioux Falls, SD

July 17, 20208 counties in South Dakota; 11 counties in Iowa; 7 counties in Minnesota

NWS Sioux Falls, SD issued this excessive heat warning at Jul 17, 2020, 2:36 PM CDT for 8 counties in South Dakota; 11 counties in Iowa; 7 counties in Minnesota. It took effect at Jul 18, 2020, 1:00 PM CDT. It was in force for 7 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jul 17, 2020, 2:36 PM CDT (19:36 UTC)
In effect from: Jul 18, 2020, 1:00 PM CDT
Expired: Jul 18, 2020, 8:00 PM CDT
In force: 7 hr
Issued by: NWS Sioux Falls, SD

All 26 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, Lyon County, MN, Murray County, MN, Nobles County, MN, Pipestone County, MN, Rock County, MN, Bon Homme County, SD, Clay County, SD, Hutchinson County, SD, Lincoln County, SD, Minnehaha County, SD, Turner County, SD, Union County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 58 km from the middle of the area, began a volume at 19:38 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, 7.6 hours before the alert went out and 269 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: 1028 J/kg
Mixed-layer CIN: -75 J/kg
Mixed-layer LCL: 924 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 145 m²/s²
0-3 km storm-relative helicity: 190 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 Jul 17, 12:01 PM CDT, 2 hours 35 minutes earlier.

Area forecast discussion, Jul 17, 12:01 PM CDT, 2 hours 35 minutes before

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Hazardous weather outlook, Jul 17, 5:29 AM CDT, 9 hours 7 minutes before

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In the hours before

Local storm report, Jul 17, 8:42 AM CDT, 5 hours 54 minutes before

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Local storm report, Jul 17, 8:44 AM CDT, 5 hours 52 minutes before

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Local storm report, Jul 17, 8:58 AM CDT, 5 hours 38 minutes before

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Local storm report, Jul 17, 9:31 AM CDT, 5 hours 5 minutes before

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Local storm report, Jul 17, 9:57 AM CDT, 4 hours 39 minutes before

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Local storm report, Jul 17, 10:48 AM CDT, 3 hours 48 minutes before

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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
Jul 17, 4:05 AM CDT	Excessive Heat Watch	FSD	Bon Homme, Clay, Hanson, Hutchinson, Lincoln, McCook and 4 more	11 hr
Jul 17, 8:01 AM CDT	Severe Thunderstorm Warning	FSD	Bon Homme	29 min
Jul 17, 8:26 AM CDT	Severe Thunderstorm Warning	FSD	Bon Homme, Yankton	49 min
Jul 17, 8:59 AM CDT	Severe Thunderstorm Warning	FSD	Hanson, Hutchinson, McCook	46 min
Jul 17, 2:36 PM CDT	Heat Advisory	FSD	Brookings, Charles Mix, Davison, Douglas, Hanson, Lake and 4 more	25 hr

Nearby

Excessive Heat Warnings in Iowa, 2020 Excessive Heat Warnings in South Dakota, 2020 Excessive Heat Warnings in Minnesota, 2020 Every excessive heat 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.