Alert archive / Wisconsin / Dense Fog Advisories in 2021

Dense Fog Advisory 9, NWS Green Bay, WI

October 9, 202114 counties in Wisconsin

NWS Green Bay, WI issued this dense fog advisory at Oct 9, 2021, 3:42 AM CDT for 14 counties in Wisconsin. It was in force for 8 hr.

The area

The counties it named.

The facts

Issued: Oct 9, 2021, 3:42 AM CDT (08:42 UTC)
Expired: Oct 9, 2021, 12:00 PM CDT
In force: 8 hr
Issued by: NWS Green Bay, WI

Counties Calumet County, WI, Langlade County, WI, Lincoln County, WI, Marathon County, WI, Menominee County, WI, Oneida County, WI, Outagamie County, WI, Portage County, WI, Shawano County, WI, Vilas County, WI, Waupaca County, WI, Waushara County, WI, Winnebago County, WI, Wood County, WI

The radar

The Green Bay radar (KGRB), 89 km from the middle of the area, began a volume at 08:44 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, 8.7 hours before the alert went out and 351 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: 409 J/kg
Mixed-layer CIN: -101 J/kg
Mixed-layer LCL: 1020 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 80 m²/s²
0-3 km storm-relative helicity: 160 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.2

Open this sounding in Storm Lab

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 Green Bay, WI wrote its last area forecast discussion before this dense fog advisory went out at Oct 8, 11:05 PM CDT, 4 hours 37 minutes earlier.

Area forecast discussion, Oct 8, 11:05 PM CDT, 4 hours 37 minutes before

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The office that day

Everything else NWS Green Bay, WI issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 9, 3:44 AM CDT	Small Craft Advisory	GRB		3 days

Nearby

Dense Fog Advisories in Wisconsin, 2021 Every 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.