Alert archive / Wisconsin / Dense Fog Advisories in 2021

Dense Fog Advisory 8, NWS La Crosse, WI

June 30, 20214 counties in Wisconsin; Allamakee County, Clayton County, Fayette County, Iowa

NWS La Crosse, WI issued this dense fog advisory at Jun 30, 2021, 4:35 AM CDT for 4 counties in Wisconsin; Allamakee County, Clayton County, Fayette County, Iowa. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued: Jun 30, 2021, 4:35 AM CDT (09:35 UTC)
Expired: Jun 30, 2021, 8:00 AM CDT
In force: 3 hr
Issued by: NWS La Crosse, WI

Counties Allamakee County, IA, Clayton County, IA, Fayette County, IA, Crawford County, WI, Grant County, WI, Richland County, WI, Vernon County, WI

The radar

The La Crosse radar (KARX), 75 km from the middle of the area, began a volume at 09:39 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

Green Bay/Straub, WI (KGRB), launched 00:00Z, 9.6 hours before the alert went out and 280 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: 1 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1147 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 7 m²/s²
0-3 km storm-relative helicity: 21 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 dense fog advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS La Crosse, WI wrote its last area forecast discussion before this dense fog advisory went out at Jun 30, 2:50 AM CDT, 1 hour 45 minutes earlier.

Area forecast discussion, Jun 30, 2:50 AM CDT, 1 hour 45 minutes before

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In the hours before

Special weather statement, Jun 29, 11:39 PM CDT, 4 hours 56 minutes before

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Special weather statement, Jun 30, 4:00 AM CDT, 35 minutes before

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      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
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        Please try again in a few minutes.
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Nearby

Dense Fog Advisories in Wisconsin, 2021 Dense Fog Advisories in Iowa, 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.