Alert archive / Alabama / Dense Fog Advisories in 2021

Dense Fog Advisory 5, NWS Birmingham, AL

March 17, 202128 counties in Alabama

NWS Birmingham, AL issued this dense fog advisory at Mar 17, 2021, 1:27 AM CDT for 28 counties in Alabama. It was in force for 6 hr.

The area

The counties it named.

The facts

Issued: Mar 17, 2021, 1:27 AM CDT (06:27 UTC)
Expired: Mar 17, 2021, 7:14 AM CDT
In force: 6 hr
Issued by: NWS Birmingham, AL

All 28 counties

Autauga County, AL, Barbour County, AL, Blount County, AL, Bullock County, AL, Calhoun County, AL, Chambers County, AL, Cherokee County, AL, Chilton County, AL, Clay County, AL, Cleburne County, AL, Coosa County, AL, Dallas County, AL, Elmore County, AL, Etowah County, AL, Jefferson County, AL, Lee County, AL, Lowndes County, AL, Macon County, AL, Montgomery County, AL, Pike County, AL, Randolph County, AL, Russell County, AL, Shelby County, AL, St. Clair County, AL, Talladega County, AL, Tallapoosa County, AL, Walker County, AL, Winston County, AL

The radar

The Birmingham radar (KBMX), 62 km from the middle of the area, began a volume at 06:27 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

Birmingham, AL (KBMX), launched 00:00Z, 6.5 hours before the alert went out and 63 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: 221 J/kg
Mixed-layer CIN: -36 J/kg
Mixed-layer LCL: 578 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: -39 m²/s²
0-3 km storm-relative helicity: 20 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.5

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 Mar 17, 12:36 AM CDT, 51 minutes earlier.

Area forecast discussion, Mar 17, 12:36 AM CDT, 51 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<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.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Hazardous weather outlook, Mar 16, 11:38 PM CDT, 1 hour 49 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<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.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

In the hours before

Special weather statement, Mar 16, 9:59 PM CDT, 3 hours 28 minutes before

Special Weather Statement
National Weather Service Birmingham AL
959 PM CDT Tue Mar 16 2021

ALZ030-170345-
Sumter AL-
959 PM CDT Tue Mar 16 2021

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN SUMTER COUNTY UNTIL
1045 PM CDT...

At 958 PM CDT, Doppler radar was tracking a strong thunderstorm over
Tamola, or near Lauderdale, moving east at 35 mph.

Pea size hail and winds up to 40 mph will be possible with this
storm.

Locations impacted include...
Livingston, York, Cuba, Epes, Boyd, The University Of West Alabama,
Bluffport, Coatopa, Old Mallard Airport, Lilita, Bellamy, I 20
Welcome Center At Cuba and Payneville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3265 8838 3269 8809 3268 8809 3268 8807
      3264 8807 3264 8808 3262 8808 3261 8807
      3243 8807 3243 8841
TIME...MOT...LOC 0258Z 265DEG 29KT 3255 8846

86/Martin

Special weather statement, Mar 16, 10:38 PM CDT, 2 hours 49 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<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.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 16, 9:59 PM CDT	Special Weather Statement	BMX	Sumter	46 min
Mar 16, 10:11 PM CDT	Severe Thunderstorm Warning	BMX	Sumter	24 min
Mar 16, 10:38 PM CDT	Special Weather Statement	BMX	Hale	37 min
Mar 17, 11:18 AM CDT	Special Weather Statement	BMX	Jefferson	27 min
Mar 17, 12:13 PM CDT	Tornado Warning	BMX	Dallas	47 min
Mar 17, 12:19 PM CDT	Areal Flood Advisory	BMX	Jefferson, Tuscaloosa	2 hr
Mar 17, 12:21 PM CDT	Severe Thunderstorm Warning	BMX	Fayette, Lamar, Marion	25 min
Mar 17, 12:41 PM CDT	Tornado Warning	BMX	Autauga	64 min
Mar 17, 12:59 PM CDT	Tornado Warning	BMX	Greene, Sumter	61 min
Mar 17, 1:18 PM CDT	Tornado Warning	BMX	Autauga, Chilton, Elmore	57 min
Mar 17, 1:40 PM CDT	Severe Thunderstorm Warning	BMX	Pickens, Tuscaloosa	28 min
Mar 17, 1:52 PM CDT	Tornado Warning	BMX	Greene, Hale, Marengo, Sumter	41 min
Mar 17, 1:58 PM CDT	Tornado Warning	BMX	Marengo	62 min
Mar 17, 1:59 PM CDT	Tornado Warning	BMX	Greene, Hale	46 min
Mar 17, 2:02 PM CDT	Tornado Warning Tornado observed	BMX	Chilton, Coosa	58 min
Mar 17, 2:09 PM CDT	Tornado Warning	BMX	Marengo	66 min
Mar 17, 2:14 PM CDT	Tornado Warning	BMX	Jefferson, Walker	61 min
Mar 17, 2:20 PM CDT	Tornado Warning Tornado observed	BMX	Tuscaloosa	40 min
Mar 17, 2:33 PM CDT	Tornado Warning Tornado observed	BMX	Clay, Coosa, Talladega	42 min
Mar 17, 2:44 PM CDT	Flash Flood Warning	BMX	Hale, Marengo, Perry	2 hr
Mar 17, 2:47 PM CDT	Areal Flood Advisory	BMX	Greene, Pickens, Sumter, Tuscaloosa	2 hr
Mar 17, 2:48 PM CDT	Areal Flood Advisory	BMX	Blount, Jefferson, Walker	2 hr
Mar 17, 2:48 PM CDT	Areal Flood Advisory	BMX	Fayette, Lamar, Marion, Walker, Winston	2 hr
Mar 17, 2:51 PM CDT	Flash Flood Warning	BMX	Jefferson	2 hr
Mar 17, 2:53 PM CDT	Tornado Warning Tornado observed	BMX	Tuscaloosa	52 min
Mar 17, 2:54 PM CDT	Tornado Warning	BMX	Dallas, Marengo, Perry	66 min
Mar 17, 2:58 PM CDT	Tornado Warning	BMX	Blount, Jefferson	34 min
Mar 17, 3:21 PM CDT	Tornado Warning	BMX	Tuscaloosa	54 min
Mar 17, 3:25 PM CDT	Flash Flood Warning	BMX	Tuscaloosa	2 hr
Mar 17, 3:28 PM CDT	Areal Flood Advisory	BMX	Dallas, Perry	2 hr
Mar 17, 3:34 PM CDT	Tornado Warning Tornado observed	BMX	Jefferson, Walker	56 min
Mar 17, 3:37 PM CDT	Tornado Warning	BMX	Marengo	38 min
Mar 17, 3:58 PM CDT	Tornado Warning Tornado observed	BMX	Jefferson	47 min
Mar 17, 3:58 PM CDT	Tornado Warning	BMX	Dallas, Perry	47 min
Mar 17, 4:12 PM CDT	Tornado Warning	BMX	Dallas	48 min
Mar 17, 4:28 PM CDT	Tornado Warning Tornado observed	BMX	Marengo	62 min
Mar 17, 4:36 PM CDT	Tornado Warning Tornado observed	BMX	Jefferson	54 min
Mar 17, 4:40 PM CDT	Tornado Warning	BMX	Autauga	50 min
Mar 17, 4:43 PM CDT	Tornado Warning	BMX	Dallas, Perry	47 min
Mar 17, 5:00 PM CDT	Tornado Warning	BMX	Chilton	60 min
Mar 17, 5:09 PM CDT	Areal Flood Advisory	BMX	Jefferson	111 min
Mar 17, 5:15 PM CDT	Tornado Warning	BMX	Chilton	60 min
Mar 17, 5:16 PM CDT	Tornado Warning Tornado observed	BMX	Blount	44 min
Mar 17, 5:23 PM CDT	Tornado Warning	BMX	Dallas, Marengo, Perry	67 min
Mar 17, 5:26 PM CDT	Areal Flood Advisory	BMX	Autauga, Chilton, Dallas, Hale, Marengo, Perry and 1 more	3 hr
Mar 17, 5:41 PM CDT	Tornado Warning	BMX	Marengo	23 min
Mar 17, 5:42 PM CDT	Tornado Warning	BMX	Chilton, Coosa, Shelby, Talladega	48 min
Mar 17, 5:48 PM CDT	Tornado Warning	BMX	Blount	42 min
Mar 17, 5:56 PM CDT	Areal Flood Advisory	BMX	Walker, Winston	44 min
Mar 17, 6:09 PM CDT	Tornado Warning	BMX	Chilton, Coosa, Shelby, Talladega	13 min
Mar 17, 6:40 PM CDT	Flash Flood Warning	BMX	Walker, Winston	3 hr
Mar 17, 6:48 PM CDT	Tornado Warning	BMX	Dallas	42 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.