Alert archive / Alabama / Dense Fog Advisories in 2021

Dense Fog Advisory 3, NWS Birmingham, AL

February 10, 202125 counties in Alabama

NWS Birmingham, AL issued this dense fog advisory at Feb 10, 2021, 10:06 PM CST for 25 counties in Alabama. It was in force for 11 hr.

The area

The counties it named.

The facts

Issued: Feb 10, 2021, 10:06 PM CST (04:06 UTC)
Expired: Feb 11, 2021, 9:00 AM CST
In force: 11 hr
Issued by: NWS Birmingham, AL

All 25 counties

Autauga County, AL, Barbour County, AL, Bibb County, AL, Bullock County, AL, Chambers County, AL, Chilton County, AL, Clay County, AL, Coosa County, AL, Dallas County, AL, Elmore County, AL, Greene County, AL, Hale County, AL, Lee County, AL, Lowndes County, AL, Macon County, AL, Marengo County, AL, Montgomery County, AL, Perry County, AL, Pike County, AL, Randolph County, AL, Russell County, AL, Shelby County, AL, Sumter County, AL, Talladega County, AL, Tallapoosa County, AL

The radar

The Maxwell AFB radar (KMXX), 59 km from the middle of the area, began a volume at 04:08 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

Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 4.1 hours before the alert went out and 196 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: 1031 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 25 m²/s²
0-3 km storm-relative helicity: 103 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 Birmingham, AL wrote its last area forecast discussion before this dense fog advisory went out at Feb 10, 6:47 PM CST, 3 hours 19 minutes earlier.

Area forecast discussion, Feb 10, 6:47 PM CST, 3 hours 19 minutes before

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Hazardous weather outlook, Feb 10, 4:57 PM CST, 5 hours 9 minutes before

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<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <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.
      </p>
      <p id="message2">
        Please try again in a few minutes.
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        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
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The office that day

Everything else NWS Birmingham, AL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 11, 4:37 AM CST	Special Weather Statement	BMX	Fayette	23 min
Feb 11, 6:15 AM CST	Special Weather Statement	BMX	Bibb, Jefferson, St. Clair, Shelby	60 min
Feb 11, 8:45 AM CST	Special Weather Statement	BMX	Randolph	45 min
Feb 11, 11:09 AM CST	Special Weather Statement	BMX	Marengo	51 min

Nearby

Dense Fog Advisories in Alabama, 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.