Severe Thunderstorm Warning 130, NWS Fort Worth, TX

Area Forecast Discussion...UPDATED
National Weather Service Fort Worth TX
738 AM CDT Tue Apr 11 2017

.AVIATION...
/12Z TAFs/

A frontal boundary is south of the I-20 corridor, but a
thunderstorm-disrupted wind field has made it difficult to discern
its precise location. The Metroplex will remain well north of the
boundary, and north flow will prevail through the daylight hours
today. Elevated convection should remain south of the Metroplex
terminals this morning, but activity closer to the frontal
boundary will continue to disrupt south departures and the Cedar
Creek cornerpost through at least mid-morning. This activity is
widespread in Central Texas and will result in intermittent
impacts at Waco.

Guidance is still convinced that MVFR ceilings should prevail this
morning in the Metroplex, but this has so far been limited to a
little wrap-around moisture invof 925mb. The back edge of the VFR
cloud deck that marks the frontal slope is just north of the
Metroplex. But with the surface front nearly stationary, the
clearing line is also unlikely to make additional progress south.

Winds will veer north of the front today, and by tonight, light
easterly surface flow will prevail. This should result in a
deterioration of both ceilings and visibility. Improvement will
gradually occur mid to late morning Wednesday as southeast winds
return.

25

&&

.PREV DISCUSSION... /ISSUED 520 AM CDT Tue Apr 11 2017/
A nearly stationary frontal boundary has kept the juiciest air
confined to areas east of I-35 and south of I-20. Persistent
convection within the warm sector has neither successfully
developed a cold pool nor completely exhausted the instability.
Even at this hour, MLCAPE values near the severe thunderstorm in
Bell County are around 1000 J/kg. This deep convection is also
benefiting from another slug of forcing aloft that will sweep
across Central Texas through daybreak. This will maintain a
marginally severe hail threat through the termination of the
severe thunderstorm watch at 7 am.

Rich 850mb flow is continuously supplying the ongoing convection
with more fuel. This deep moisture has resulted in some
extraordinary rainfall rates, and the flooding threat will
continue through daybreak, particularly where additional cells
track over areas that have already seen heavy rainfall during this
event. The flash flood watch remains in effect through 7 am though
the western extent is already seeing the heavy rain potential
diminish. After 7 am, drying westerly flow will ensue within the
850-700mb layer as the current impulse passes to the east. This
should end the heavy rain threat though runoff may continue to
cause flooding impacts throughout the morning commute.

Although there is little warm advection or moisture flux across
the surface boundary, there remains considerable elevated
instability above the frontal layer. This was realized across
North Central Texas during the early morning hours in vicinity of
the 850mb front. The steep mid-level lapse rates helped maintain
hailcores, but the forcing that helped overcome minimal storm-
relative flow at the base of these updrafts has now passed to the
east. As a result, the overnight storms that tormented the
Metroplex have come to an end, and little if any additional
convection is expected that deep into the cool air the remainder
of the day.

Mid-level ridging will make for a much quieter night tonight into
Wednesday morning, but the progressive flow will assure the
respite is short-lived. Some isolated (mainly daytime) showers
and storms will be possible both Wednesday and Thursday as
destabilizing southwesterly flow prevails. The main shortwave
forcing will be confined to West Texas and the Panhandle, but some
of the activity that originates there could impact our northwest
counties into the evening/overnight hours each day. The severe
threat appears low with this activity, but the stronger cells
could contain small hail.

The early part of the coming weekend may be the next break in the
action, but thunderstorms are still expected to return Sunday and
Monday.

25

&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    73  61  78  63  79 /  20  10  20  10  20
Waco                74  61  80  61  79 /  50  10  20  10  20
Paris               70  59  76  60  78 /  30  10  20  10  20
Denton              73  58  78  61  78 /  20   5  20  10  20
McKinney            72  58  77  60  79 /  20  10  20  10  20
Dallas              74  62  79  64  80 /  20  10  20  10  20
Terrell             73  60  79  63  80 /  30  10  20  10  10
Corsicana           73  62  79  62  79 /  40  10  20  10  10
Temple              73  62  79  61  79 /  60  10  20  10  20
Mineral Wells       74  57  78  61  78 /  10   5  20  20  20

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch until 7 AM CDT this morning for TXZ135-142>148-
156>162-174-175.

&&

25/25

<!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>

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FORT WORTH TX
752 AM CDT TUE APR 11 2017

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

0720 AM     HAIL             ALVARADO                32.40N  97.22W
04/11/2017  E1.50 INCH       JOHNSON            TX   PUBLIC

            PING PONG SIZE HAIL IN ALVARADO JUNIOR HIGH SCHOOL.

Special Weather Statement
National Weather Service Fort Worth TX
806 AM CDT TUE APR 11 2017

TXZ156>158-111345-
Coryell TX-Lampasas TX-Bell TX-
806 AM CDT TUE APR 11 2017

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN CORYELL...
SOUTHEASTERN LAMPASAS AND WEST CENTRAL BELL COUNTIES UNTIL 845 AM
CDT...

At 806 AM CDT, Doppler radar was tracking a strong thunderstorm over
Kempner, or 7 miles southwest of Copperas Cove, moving east at 15
mph.

Dime size hail will be possible with this storm.

Locations impacted include...
Killeen, Copperas Cove, Fort Hood and Kempner.

LAT...LON 3104 9791 3103 9804 3116 9800 3114 9779
      3094 9785
TIME...MOT...LOC 1306Z 274DEG 14KT 3104 9798

Dunn

Special Weather Statement
National Weather Service Fort Worth TX
807 AM CDT TUE APR 11 2017

TXZ157-111345-
Coryell TX-
807 AM CDT TUE APR 11 2017

...SIGNIFICANT WEATHER ADVISORY FOR NORTH CENTRAL CORYELL COUNTY
UNTIL 845 AM CDT...

At 807 AM CDT, Doppler radar was tracking a strong thunderstorm 12
miles northwest of Gatesville, moving east at 25 mph.

Dime size hail will be possible with this storm.

Locations impacted include...
Gatesville.

LAT...LON 3167 9777 3150 9764 3144 9797 3156 9799
TIME...MOT...LOC 1307Z 247DEG 23KT 3156 9790

Dunn