Alert archive / Alabama / Areal Flood Advisories in 2021

Areal Flood Advisory 85, NWS Birmingham, AL

July 20, 2021Jefferson County, Alabama

NWS Birmingham, AL issued this areal flood advisory at Jul 20, 2021, 2:05 AM CDT for Jefferson County, Alabama. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued: Jul 20, 2021, 2:05 AM CDT (07:05 UTC)
Expired: Jul 20, 2021, 5:15 AM CDT
In force: 3 hr
Issued by: NWS Birmingham, AL
Area: Storm-based polygon

County Jefferson County, AL

The radar

The Birmingham radar (KBMX), 44 km from the middle of the area, began a volume at 07:05 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, 7.1 hours before the alert went out and 223 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: 569 J/kg
Mixed-layer CIN: -17 J/kg
Mixed-layer LCL: 673 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 96 m²/s²
0-3 km storm-relative helicity: 104 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 areal flood 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 areal flood advisory went out at Jul 20, 12:37 AM CDT, 1 hour 28 minutes earlier.

Area forecast discussion, Jul 20, 12:37 AM CDT, 1 hour 28 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, Jul 19, 4:42 AM CDT, 21 hours 23 minutes before

Hazardous Weather Outlook
National Weather Service Birmingham AL
442 AM CDT Mon Jul 19 2021

ALZ011>015-017>050-201245-
Marion-Lamar-Fayette-Winston-Walker-Blount-Etowah-Calhoun-Cherokee-
Cleburne-Pickens-Tuscaloosa-Jefferson-Shelby-St. Clair-Talladega-
Clay-Randolph-Sumter-Greene-Hale-Perry-Bibb-Chilton-Coosa-Tallapoosa-
Chambers-Marengo-Dallas-Autauga-Lowndes-Elmore-Montgomery-Macon-
Bullock-Lee-Russell-Pike-Barbour-
442 AM CDT Mon Jul 19 2021

This Hazardous Weather Outlook is for the counties served by the
National Weather Service office in Birmingham.

.DAY ONE...Outlook through Tonight.

Periods of heavy rain at times may occur through tonight across
portions of Central Alabama. This could cause isolated areas of
flooding and ponding of water in low lying areas. Use caution and
allow extra time for travel.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Activation of storm spotters and emergency management may be needed
through tonight.

08

In the hours before

Local storm report, Jul 19, 8:48 PM CDT, 5 hours 17 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
Jul 19, 7:00 PM CDT	Areal Flood Advisory	BMX	St. Clair	3 hr
Jul 19, 7:01 PM CDT	Areal Flood Advisory	BMX	Tuscaloosa	3 hr
Jul 19, 7:02 PM CDT	Areal Flood Advisory	BMX	Fayette	118 min
Jul 19, 7:34 PM CDT	Areal Flood Advisory	BMX	Greene	116 min
Jul 19, 7:53 PM CDT	Areal Flood Advisory	BMX	Walker	2 hr
Jul 19, 8:19 PM CDT	Areal Flood Advisory	BMX	Jefferson	3 hr
Jul 20, 8:42 AM CDT	Flash Flood Watch	BMX	Bibb, Blount, Calhoun, Cherokee, Clay, Cleburne and 8 more	12 hr
Jul 20, 12:14 PM CDT	Special Weather Statement	BMX	Pike	46 min
Jul 20, 1:10 PM CDT	Special Weather Statement	BMX	Autauga, Lowndes, Montgomery	50 min
Jul 20, 2:04 PM CDT	Special Weather Statement	BMX	Autauga, Elmore, Macon	41 min
Jul 20, 2:29 PM CDT	Areal Flood Advisory	BMX	Bibb, Jefferson, Shelby, Tuscaloosa	3 hr
Jul 20, 2:41 PM CDT	Areal Flood Advisory	BMX	Bibb, Chilton, Perry	3 hr
Jul 20, 2:48 PM CDT	Areal Flood Advisory	BMX	Jefferson, Shelby	3 hr
Jul 20, 3:34 PM CDT	Areal Flood Advisory	BMX	Shelby	3 hr
Jul 20, 3:41 PM CDT	Flash Flood Warning	BMX	Shelby	3 hr
Jul 20, 3:44 PM CDT	Areal Flood Advisory	BMX	Marion	2 hr
Jul 20, 4:00 PM CDT	Areal Flood Advisory	BMX	St. Clair, Shelby	3 hr
Jul 20, 4:06 PM CDT	Areal Flood Advisory	BMX	Walker, Winston	114 min
Jul 20, 4:22 PM CDT	Areal Flood Advisory	BMX	St. Clair	3 hr
Jul 20, 5:56 PM CDT	Areal Flood Advisory	BMX	Marion, Walker, Winston	2 hr
Jul 20, 6:03 PM CDT	Areal Flood Advisory	BMX	Blount	117 min

Nearby

Areal Flood Advisories in Alabama, 2021 Every areal flood 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.