Alert archive / South Dakota / Frost Advisories in 2026

Frost Advisory 1, NWS Sioux Falls, SD

April 30, 202624 counties in South Dakota; 11 counties in Iowa; 8 counties in Minnesota

NWS Sioux Falls, SD issued this frost advisory at Apr 30, 2026, 1:36 PM CDT for 24 counties in South Dakota; 11 counties in Iowa; 8 counties in Minnesota. It took effect at May 1, 2026, 1:00 AM CDT. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued: Apr 30, 2026, 1:36 PM CDT (18:36 UTC)
In effect from: May 1, 2026, 1:00 AM CDT
Expired: May 1, 2026, 8:00 AM CDT
In force: 7 hr
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 18:40 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, 6.6 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: 1287 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: -9 m²/s²
0-3 km storm-relative helicity: 90 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 Apr 30, 12:28 PM CDT, 1 hour 8 minutes earlier.

Area forecast discussion, Apr 30, 12:28 PM CDT, 1 hour 8 minutes before

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Hazardous weather outlook, Apr 30, 3:41 AM CDT, 9 hours 55 minutes before

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Nearby

Frost Advisories in South Dakota, 2026 Frost Advisories in Iowa, 2026 Frost Advisories in Minnesota, 2026 Every frost advisory in 2026

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.