Alert archive / Iowa / Dense Fog Advisories in 2021

Dense Fog Advisory 2, NWS Quad Cities, IA

January 3, 202121 counties in Iowa; 13 counties in Illinois; Clark County, Scotland County, Missouri

NWS Quad Cities, IA issued this dense fog advisory at Jan 3, 2021, 2:22 PM CST for 21 counties in Iowa; 13 counties in Illinois; Clark County, Scotland County, Missouri. It took effect at Jan 3, 2021, 6:00 PM CST. It was in force for 25 hr.

The area

The counties it named.

The facts

Issued: Jan 3, 2021, 2:22 PM CST (20:22 UTC)
In effect from: Jan 3, 2021, 6:00 PM CST
Expired: Jan 4, 2021, 6:31 PM CST
In force: 25 hr
Issued by: NWS Quad Cities, IA

All 36 counties

Benton County, IA, Buchanan County, IA, Cedar County, IA, Clinton County, IA, Delaware County, IA, Des Moines County, IA, Dubuque County, IA, Henry County, IA, Iowa County, IA, Jackson County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Lee County, IA, Linn County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Van Buren County, IA, Washington County, IA, Bureau County, IL, Carroll County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, Jo Daviess County, IL, McDonough County, IL, Mercer County, IL, Putnam County, IL, Rock Island County, IL, Stephenson County, IL, Warren County, IL, Whiteside County, IL, Clark County, MO, Scotland County, MO

The radar

The Quad Cities radar (KDVN), 41 km from the middle of the area, began a volume at 20:23 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

Davenport, (KDVN), launched 12:00Z, 8.4 hours before the alert went out and 47 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1399 m above ground
0-6 km bulk shear: 7 kt
0-1 km storm-relative helicity: 67 m²/s²
0-3 km storm-relative helicity: 86 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 Quad Cities, IA wrote its last area forecast discussion before this dense fog advisory went out at Jan 3, 11:01 AM CST, 3 hours 21 minutes earlier.

Area forecast discussion, Jan 3, 11:01 AM CST, 3 hours 21 minutes before

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Hazardous weather outlook, Jan 3, 3:50 AM CST, 10 hours 32 minutes before

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In the hours before

Special weather statement, Jan 3, 11:58 AM CST, 2 hours 24 minutes before

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      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
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Nearby

Dense Fog Advisories in Iowa, 2021 Dense Fog Advisories in Illinois, 2021 Dense Fog Advisories in Missouri, 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.