Alert archive / Iowa / Winter Weather Advisories in 2021
Winter Weather Advisory 11, NWS Des Moines, IA
NWS Des Moines, IA issued this winter weather advisory at Feb 20, 2021, 3:32 AM CST for 51 counties in Iowa. It took effect at Feb 21, 2021, 6:00 AM CST. It was in force for 14 hr.
The area
The counties it named.
The facts
- Issued
- Feb 20, 2021, 3:32 AM CST (09:32 UTC)
- In effect from
- Feb 21, 2021, 6:00 AM CST
- Expired
- Feb 21, 2021, 8:00 PM CST
- In force
- 14 hr
- Issued by
- NWS Des Moines, IA
All 51 counties
Adair County, IA, Adams County, IA, Appanoose County, IA, Audubon County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Butler County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Cerro Gordo County, IA, Clarke County, IA, Crawford County, IA, Dallas County, IA, Davis County, IA, Decatur County, IA, Emmet County, IA, Franklin County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Humboldt County, IA, Jasper County, IA, Kossuth County, IA, Lucas County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Monroe County, IA, Palo Alto County, IA, Pocahontas County, IA, Polk County, IA, Poweshiek County, IA, Ringgold County, IA, Sac County, IA, Story County, IA, Tama County, IA, Taylor County, IA, Union County, IA, Wapello County, IA, Warren County, IA, Wayne County, IA, Webster County, IA, Winnebago County, IA, Worth County, IA, Wright County, IA
The radar
The Des Moines radar (KDMX), 23 km from the middle of the area, began a volume at 09:31 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 00:00Z, 9.5 hours before the alert went out and 230 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1319 m above ground
- 0-6 km bulk shear
- 55 kt
- 0-1 km storm-relative helicity
- 118 m²/s²
- 0-3 km storm-relative helicity
- 249 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
What forecasters said that day
The local office's own words before this winter weather advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Des Moines, IA wrote its last area forecast discussion before this winter weather advisory went out at Feb 19, 11:40 PM CST, 3 hours 52 minutes earlier.
Area forecast discussion, Feb 19, 11:40 PM CST, 3 hours 52 minutes before
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</html>Hazardous weather outlook, Feb 20, 3:18 AM CST, 14 minutes before
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</html>In the hours before
Special weather statement, Feb 19, 11:48 PM CST, 3 hours 44 minutes before
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<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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</html>Nearby
Winter Weather Advisories in Iowa, 2021Every winter weather advisory in 2021
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.