Alert archive / South Dakota / Freeze Warnings in 2009

Freeze Warning 1, NWS Sioux Falls, SD

October 8, 200921 counties in South Dakota; Lyon County, Iowa; 6 counties in Minnesota

NWS Sioux Falls, SD issued this freeze warning at Oct 8, 2009, 3:43 AM CDT for 21 counties in South Dakota; Lyon County, Iowa; 6 counties in Minnesota. It took effect at Oct 9, 2009, 3:00 AM CDT. It was in force for 5 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: Oct 8, 2009, 3:43 AM CDT (08:43 UTC)
In effect from: Oct 9, 2009, 3:00 AM CDT
Expired: Oct 9, 2009, 8:00 AM CDT
In force: 5 hr
Issued by: NWS Sioux Falls, SD

All 28 counties

Lyon County, IA, 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, 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

The radar

The Sioux Falls radar (KFSD), 56 km from the middle of the area, began a volume at 08:43 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 00:00Z, 8.7 hours before the alert went out and 323 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: 2007 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 192 m²/s²
0-3 km storm-relative helicity: 242 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 freeze 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 freeze warning went out at Oct 8, 3:30 AM CDT, 13 minutes earlier.

Area forecast discussion, Oct 8, 3:30 AM CDT, 13 minutes before

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Nearby

Freeze Warnings in South Dakota, 2009 Freeze Warnings in Minnesota, 2009 Freeze Warnings in Iowa, 2009 Every freeze warning in 2009

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.