Alert archive / Iowa / Winter Weather Advisories in 2021
Winter Weather Advisory 16, NWS Des Moines, IA
NWS Des Moines, IA issued this winter weather advisory at Dec 9, 2021, 11:44 AM CST for 19 counties in Iowa. It took effect at Dec 10, 2021, 12:00 PM CST. It was in force for 18 hr.
The area
The counties it named.
The facts
- Issued
- Dec 9, 2021, 11:44 AM CST (17:44 UTC)
- In effect from
- Dec 10, 2021, 12:00 PM CST
- Expired
- Dec 11, 2021, 6:00 AM CST
- In force
- 18 hr
- Issued by
- NWS Des Moines, IA
Counties Black Hawk County, IA, Boone County, IA, Bremer County, IA, Butler County, IA, Calhoun County, IA, Carroll County, IA, Crawford County, IA, Franklin County, IA, Greene County, IA, Grundy County, IA, Hamilton County, IA, Hardin County, IA, Humboldt County, IA, Marshall County, IA, Sac County, IA, Story County, IA, Tama County, IA, Webster County, IA, Wright County, IA
The radar
The Des Moines radar (KDMX), 70 km from the middle of the area, began a volume at 17:49 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, 5.7 hours before the alert went out and 251 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
- 1315 m above ground
- 0-6 km bulk shear
- 55 kt
- 0-1 km storm-relative helicity
- 362 m²/s²
- 0-3 km storm-relative helicity
- 429 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 Dec 9, 5:52 AM CST, 5 hours 52 minutes earlier.
Area forecast discussion, Dec 9, 5:52 AM CST, 5 hours 52 minutes before
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</html>Hazardous weather outlook, Dec 9, 8:44 AM CST, 3 hours before
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</html>The office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 9, 5:14 AM CST | Winter Weather Advisory | DMX | Black Hawk, Boone, Bremer, Butler, Cerro Gordo, Franklin and 9 more | 3 hr |
| Dec 9, 11:44 AM CST | Winter Storm Warning | DMX | Cerro Gordo, Emmet, Hancock, Kossuth, Palo Alto, Pocahontas and 2 more | 42 hr |
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.