Alert archive / South Dakota / Frost Advisories in 2022

Frost Advisory 1, NWS Sioux Falls, SD

May 21, 202221 counties in South Dakota; 11 counties in Iowa; 8 counties in Minnesota

NWS Sioux Falls, SD issued this frost advisory at May 21, 2022, 2:47 PM CDT for 21 counties in South Dakota; 11 counties in Iowa; 8 counties in Minnesota. It took effect at May 21, 2022, 11:00 PM CDT. It was in force for 10 hr.

The area

The counties it named.

The facts

Issued: May 21, 2022, 2:47 PM CDT (19:47 UTC)
In effect from: May 21, 2022, 11:00 PM CDT
Expired: May 22, 2022, 9:00 AM CDT
In force: 10 hr
Issued by: NWS Sioux Falls, SD

All 40 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, Bon Homme County, SD, Brookings County, SD, Charles Mix County, SD, Clay County, SD, Davison County, SD, Douglas County, SD, Gregory County, SD, Hanson County, SD, Hutchinson 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), 13 km from the middle of the area, began a volume at 19:46 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

Omaha, NE (KOAX), launched 12:00Z, 7.8 hours before the alert went out and 241 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: 1002 m above ground
0-6 km bulk shear: 86 kt
0-1 km storm-relative helicity: -132 m²/s²
0-3 km storm-relative helicity: -7 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 frost advisory 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 frost advisory went out at May 20, 6:26 PM CDT, 20 hours 21 minutes earlier.

Area forecast discussion, May 20, 6:26 PM CDT, 20 hours 21 minutes before

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Hazardous weather outlook, May 20, 4:05 PM CDT, 22 hours 42 minutes before

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<body>
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    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
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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
May 21, 2:47 PM CDT	Freeze Warning	FSD	Aurora, Beadle, Brule, Davison, Jerauld, Kingsbury and 2 more	18 hr

Nearby

Frost Advisories in South Dakota, 2022 Frost Advisories in Iowa, 2022 Frost Advisories in Minnesota, 2022 Every frost advisory in 2022

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.