Alert archive / Iowa / Dense Fog Advisories in 2021
Dense Fog Advisory 6, NWS Des Moines, IA
NWS Des Moines, IA issued this dense fog advisory at Feb 22, 2021, 12:47 AM CST for 17 counties in Iowa. It was in force for 5 hr.
The area
The counties it named.
The facts
- Issued
- Feb 22, 2021, 12:47 AM CST (06:47 UTC)
- Expired
- Feb 22, 2021, 6:00 AM CST
- In force
- 5 hr
- Issued by
- NWS Des Moines, IA
Counties Audubon County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Crawford County, IA, Emmet County, IA, Greene County, IA, Guthrie County, IA, Hancock County, IA, Humboldt County, IA, Kossuth County, IA, Palo Alto County, IA, Pocahontas County, IA, Sac County, IA, Webster County, IA, Winnebago County, IA, Wright County, IA
The radar
The Des Moines radar (KDMX), 106 km from the middle of the area, began a volume at 06:44 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, 6.8 hours before the alert went out and 272 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
- 578 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 36 m²/s²
- 0-3 km storm-relative helicity
- 32 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
What forecasters said that day
The local office's own words before this dense fog 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 dense fog advisory went out at Feb 21, 5:53 PM CST, 6 hours 54 minutes earlier.
Area forecast discussion, Feb 21, 5:53 PM CST, 6 hours 54 minutes before
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</html>Hazardous weather outlook, Feb 21, 3:38 PM CST, 9 hours 9 minutes before
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</html>Nearby
Dense Fog Advisories in Iowa, 2021Every dense fog 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.