Alert archive / Alabama / Areal Flood Warnings in 2017

Areal Flood Warning 2, NWS Birmingham, AL

January 22, 2017Cherokee County, Etowah County, Alabama

NWS Birmingham, AL issued this areal flood warning at Jan 22, 2017, 10:43 PM CST for Cherokee County, Etowah County, Alabama. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jan 22, 2017, 10:43 PM CST (04:43 UTC)
Expired
Jan 23, 2017, 4:45 AM CST
In force
6 hr
Issued by
NWS Birmingham, AL
Area
Storm-based polygon
Flood severity
None

Counties Cherokee County, AL, Etowah County, AL

The radar

The Northeast Alabama radar (KHTX), 94 km from the middle of the area, began a volume at 04:43 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, 4.7 hours before the alert went out and 136 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-pSkew-T log-p diagram, Birmingham, AL at 00:00Z on 2017-01-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Birmingham, AL at 00:00Z on 2017-01-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -145 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
771 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
-145 m²/s²
0-3 km storm-relative helicity
-73 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 warning 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 warning went out at Jan 22, 11:20 AM CST, 11 hours 23 minutes earlier.

Area forecast discussion, Jan 22, 11:20 AM CST, 11 hours 23 minutes before
Area Forecast Discussion
National Weather Service Birmingham AL
1120 AM CST Sun Jan 22 2017

.UPDATE...
For 18Z Aviation.

&&

.DISCUSSION...

Another round of showers and thunderstorms today as an upper low
over Texas tracks eastward across Alabama this evening. The closed
upper low will deepen and trigger a surface low development across
south Alabama later this morning. This surface low will also
deepen as it tracks northeast across east Alabama. The track of
the surface low is very critical to determining the highest
tornado threat area. The southeast counties, mainly along and
south of I-85 still look like the prime area for tornado
formation today, and have elevated this area in our threat area
graphics. The surface low will track quickly northeast and the
severe threat will end fairly quickly once the surface low crosses
over into Georgia, sometime around 3 pm. This is a very dynamic
system and widespread showers and elevated thunderstorms expected
on the north and west side of the upper low. Temperatures near the
center of the 500mb upper low will be near -25 celsius, and steep
lapse rates could produce some large hail across the southeast
counties in the more vigorous convection, with small hail as far
north as I-20.

Cooler and more stable air will overspread all of central Alabama
this evening. Scattered to numerous showers will continue across
central Alabama tonight as the upper low center moves across the
area. A very tight surface pressure gradient will develop later
tonight as the surface low deepens and moves east of Alabama.
Sustained west to northwest winds of 15 to 25 mph will likely
develop after midnight and last through Monday morning, and a wind
advisory may be issued later today. Monday will be a very chilly
day with brisk northwest winds and lingering clouds. Skies will
gradually clear from west to east Monday afternoon, and there may
be some lingering showers across east Alabama Monday morning.

Mostly clear and dry Monday night and Tuesday. A weak front will
pass through the area Wednesday and Wednesday night and bring some
scattered showers. Drier and slightly cooler conditions Thursday
through Saturday.

58/rose

&&

.AVIATION...
18Z TAF Discussion.

Today will be another difficult day to forecast for aviation. A
strong low pressure system will be moving through Central AL
today with storms and rain building along the warm front as it
lifts northward through the afternoon. Hi-Res models have not been
handling the timing overly well this morning, trying to move the
warm front and rain/storms through quicker than is actually
occurring. Therefore, have slowed the progress of TSRA and RA in
the terminal forecasts. Storms have begun moving into the TOI and
MGM areas around 17z, and should progress northward during the
afternoon, impacting all TAF sites by late afternoon. Behind the
warm front and low pressure system, winds will become
northwesterly as light rain showers will persist through midnight
for Central AL. Behind the rain shield, gusty northwesterly winds
will be likely. Have issued a Wind Advisory for all of Central AL
from midnight tonight through 6:00pm Monday. Sustained winds
15-20kts with gusts up to 30-35kts possible.

25/Owen

&&

.FIRE WEATHER...

Another round of showers and thunderstorms today, with heavy
rainfall at times. Much cooler and breezy tonight with showers
likely. Rain free conditions Monday and Tuesday. No fire weather
concerns.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     63  48  53  35  59 /  80  80  30   0   0
Anniston    64  50  55  37  60 /  80  80  30   0   0
Birmingham  64  49  56  36  61 /  80  80  20   0   0
Tuscaloosa  63  49  56  37  63 /  80  70  10   0   0
Calera      63  49  56  38  62 /  80  70  10   0   0
Auburn      64  51  57  40  61 /  70  60  20   0   0
Montgomery  66  51  60  39  64 /  70  50  10   0   0
Troy        68  50  59  39  64 /  70  50  10   0   0

&&

.BMX WATCHES/WARNINGS/ADVISORIES/...
Wind Advisory from midnight tonight to 6 PM CST Monday for the
following counties: Autauga...Barbour...Bibb...Blount...
Bullock...Calhoun...Chambers...Cherokee...Chilton...Clay...
Cleburne...Coosa...Dallas...Elmore...Etowah...Fayette...Greene...
Hale...Jefferson...Lamar...Lee...Lowndes...Macon...Marengo...
Marion...Montgomery...Perry...Pickens...Pike...Randolph...
Russell...Shelby...St. Clair...Sumter...Talladega...Tallapoosa...
Tuscaloosa...Walker...Winston.

&&
Hazardous weather outlook, Jan 22, 3:37 PM CST, 7 hours 6 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, Jan 22, 5:38 PM CST, 5 hours 5 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.

IssuedProductOfficeCountiesLasted
Jan 22, 7:51 PM CSTFlash Flood WarningBMXCherokee, Etowah3 hr

Nearby

Areal Flood Warnings in Alabama, 2017Every areal flood warning in 2017

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.