Special Weather Statement, NWS Birmingham, AL

Area Forecast Discussion
National Weather Service Birmingham AL
354 PM CDT Thu Jul 27 2017

.SHORT TERM...
Through Tonight.

Scattered thunderstorms have developed across portions of east
Central Alabama, on the eastern edge of the upper level ridge
nosing into the area from the west. This activity will diminish
this evening, with much of the area seeing rainfree conditions
overnight. As a front approaches from the north late tonight,
showers and storms could return to northern portions before
sunrise.

Looking at impacts for tomorrow, strong to severe storms remain
possible (note the details below from the previous discussion).
Additionally, heavy rainfall will be possible with all activity.
Hi-res guidance continues to show several rounds of storms, moving
over north Central Alabama tomorrow and tomorrow night. Given
above normal rainfall this summer and recent heavy rainfall,
localized flash flooding will be possible as storms move over the
same areas.

If you live in an area that is prone to flash flooding or near a
stream/creek that is quick to rise with heavy rainfall, remain
aware of changing weather and flood conditions tomorrow and
tomorrow night.

14

.LONG TERM...
Friday through Thursday.

We begin Friday with a cold front stretched through the Ohio River
Valley pushing southward into Northern AL. This cold front is
associated with a broad surface low near the base of a developing
longwave trough. The upper level low pressure system is offset well
to the north, over the Great Lakes. We could see some early
shower/thunderstorm activity across the far northern counties Friday
morning. The cold front slowly moves southward during the early part
of the day Friday. By Friday evening, the surface low strengthens
and troughing pattern amplifies over the Eastern US. This
strengthens the northerly flow and pushes the cold front through the
area quickly Friday evening into early Saturday morning. There are
still timing differences in the models, so specific arrival times
will need to be re-evaluated with future model runs. Expect some
decrease in storm coverage after sunset Friday night, increasing
again Saturday morning across the southern most counties as the cold
front finally pushes south of the area. Ahead of the cold front,
PWATs are still showing up in the 2.3-2.4" range, so expect very
heavy rainfall with any storms that do develop. Due to the increased
forcing from the cold front and increased precip loading, I can't
rule out the potential for some storms to produce strong to severe
downburst winds. 850mb temps are around 20C, making lapse rates very
low; therefore, not expected a large hail threat. We could see some
small hail in the strongest storms, but otherwise the main threat
will be isolated damaging winds and localized flooding. Have
continued mention for low confidence severe for these threats.

The low pressure system slides southeastward Saturday and
essentially stalls out over the Tidewater Region of Coastal Virginia
through early next week. This keeps us under northerly flow on the
back side of the deep trough, leading to drier and cooler weather
through at least mid-week. Models hint at another impulse digging
through the main trough towards the end of next week that could
bring another round or showers/storms. Otherwise, expect below
average temps and precip coverage for most of the upcoming week.

25/Owen

&&

.AVIATION...
12Z TAF Discussion.

Scattered showers and storms developing along and east of a line
from generally GAD to EET to SEM. Expect most activity to remain
east of this line this afternoon, with a general slow east to
southeast storm motion.  Storms will produce heavy rainfall, brief
wind gusts, and frequent lightning. This activity will diminish
during the early evening hours, with clearing skies.

Have included localized MVFR fog overnight, but increased westerly
boundary layer winds should prevent more widespread development.
Coverage of showers and thunderstorms will be greater tomorrow as a
front slowly pushes into the area. Uncertainty of timing at northern
terminals exists and will hold off on mentioning TSRA.

14

&&

.FIRE WEATHER...

Isolated to scattered rain chances today, with best chances in the
east. Hot and humid weather expected today. Cold front approaches
on Friday, increasing rain chances. Cooler and drier weather
behind the front through the weekend. No fire weather concerns at
this time.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     74  88  71  87  66 /  20  70  50  10   0
Anniston    75  87  72  87  67 /  20  70  50  20   0
Birmingham  77  89  73  87  67 /  20  70  50  20   0
Tuscaloosa  76  91  74  89  68 /  10  70  50  20   0
Calera      76  88  74  88  68 /  20  60  50  30   0
Auburn      75  91  73  86  69 /  30  30  40  40  10
Montgomery  77  94  75  89  70 /  20  30  40  50  10
Troy        75  95  74  87  69 /  30  30  40  60  20

&&

.BMX WATCHES/WARNINGS/ADVISORIES/...
Heat Advisory until 7 PM CDT this evening for the following
counties: Bibb...Dallas...Fayette...Greene...Hale...Lamar...
Marengo...Marion...Perry...Pickens...Sumter...Tuscaloosa.

Flash Flood Watch from Friday morning through Friday evening for
the following counties: Bibb...Blount...Calhoun...Cherokee...
Clay...Cleburne...Etowah...Fayette...Jefferson...Lamar...
Marion...Pickens...Randolph...Shelby...St. Clair...Talladega...
Tuscaloosa...Walker...Winston.

&&

Hazardous Weather Outlook
National Weather Service Birmingham AL
408 AM CDT Thu Jul 27 2017

ALZ011>015-017>050-281215-
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-
408 AM CDT Thu Jul 27 2017

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

.DAY ONE...Outlook through Tonight.

Heat indices could reach 105 degrees this afternoon across the
western portions of Central Alabama.

Isolated severe thunderstorms may develop east of the interstate 65
corridor this afternoon. The main threat with these storms will be
damaging winds and localized flooding.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Thunderstorms will develop ahead of an approaching cool front late
Friday afternoon and into Friday night. Some storms may become
severe, producing damaging winds. Heavy rainfall will also be
possible, and could result in localized flooding.

.SPOTTER INFORMATION STATEMENT...

Activation of storm spotters and emergency management may be
necessary Friday afternoon and Friday night.

Special Weather Statement
National Weather Service Birmingham AL
422 PM CDT THU JUL 27 2017

ALZ047-272145-
Lee AL-
422 PM CDT THU JUL 27 2017

...SIGNIFICANT WEATHER ADVISORY FOR EASTERN LEE COUNTY UNTIL 445 PM
CDT...

At 422 PM CDT, Doppler radar was tracking a strong thunderstorm near
Beans Mill, or 8 miles east of Opelika, moving south at 15 mph.

Winds in excess of 40 mph will be possible with this storm.

Locations impacted include...
Griffen Mill, Bleecker and Ladonia.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

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 3247 8532 3269 8528 3268 8513 3247 8509
TIME...MOT...LOC 2122Z 357DEG 14KT 3263 8524

89^GSatterwhite

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
423 PM CDT THU JUL 27 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0310 PM     TSTM WND DMG     3 SSW STILL WATERS RESO 32.71N 85.83W
07/27/2017                   TALLAPOOSA         AL   EMERGENCY MNGR

            TREES REPORTED DOWN ALONG HIGHWAY 50 NEAR
            LAKE MARTIN. TIME EST. FROM RADAR.

&&

AJP

<!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>

<!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>

<!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>

<!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>