Severe Thunderstorm Warning 182, NWS Morristown, TN

Area Forecast Discussion
National Weather Service Morristown TN
310 PM EDT Sat Jul 29 2023

...New SHORT TERM, LONG TERM...

.SHORT TERM...
(This evening through Sunday)
Issued at 308 PM EDT Sat Jul 29 2023

Key Messages:

1. A few to several strong to severe storms expected this
afternoon/evening. Greatest chances will along I-40 and northward,
especially across northeast TN and southwest VA.

2. Main threats will be isolated damaging wind gusts and localized
flooding due to heavy rainfall.

Discussion:

Thunderstorms are currently ongoing to our north across central KY
within a weak area of surface convergence. CAMs in good agreement
that this activity continues to develop and move south into
southwest VA and northeast TN around 20Z. Thereafter, these storms
will continue to move south into the central East TN Valley. The
highest coverage of storms is expected along and north of I-40, with
more isolated to scattered activity the further south you go into
the southern TN Valley. Current rap analysis on SPC's meso page
shows robust instability across the area with 4000 to 4500 J/kg of
SBCAPE and 2500 to 3000 J/kg MLCAPE. Thankfully shear is non-
existent so these storms will be of the pulse variety and driven by
afternoon heating and outflows.

The main threats with these storms will be isolated damaging winds
gusts and localized flooding. The wind threat is due to a modest
amount of DCAPE with roughly 1000 J/kg in place. The heavy rainfall
is due to high PW values and good warm layer cloud depths of around
10kt feet. The steering flow is also very weak with 850-300 mb mean
winds of 10 to 15kts. This will allow for slow storm motions thus
increasing the flooding threat for areas that get hit by repeated
rounds of storms. Latest WPC QPF puts 0.75 to 1" of rain in for most
areas across northeast TN and southwest VA this afternoon. Some areas
may receive up to 2" of rainfall if they see repeated storms.

The activity that is currently ongoing across the central east TN
Valley was not forecast well by the CAMS. Given that there are
already storms ongoing, and the environment in place, I expect these
storms to continue before additional activity moves in from the
north. Some of these storms may be strong to severe.

CAMS show the bulk of the activity dying off by midnight, with only
isolated showers and storms thereafter. Areas that receive rainfall
will see locally dense fog overnight. Rainfall chances lower
tomorrow with only slight chance to low end chance POPs in place
during the afternoon hours.

&&

.LONG TERM...
(Sunday night through next Saturday)
Issued at 308 PM EDT Sat Jul 29 2023

Key Messages:

1. Drier weather Monday through Wednesday.

2. Chances for showers and storms return late Wednesday through
Saturday.

Discussion:

Not seeing much in the way of changes with the extended. The pattern
generally remains the same, as we start the period with a ridge axis
located across the four-corners. Further north, low pressure will
remain across Quebec, placing the FA within northwest flow aloft.
Surface high pressure will settle across the Ohio Valley, bringing
northerly wind and a much drier atmosphere. Mostly dry weather is
expected Monday through much of Wednesday. Don't want to completely
rule out a stray shower or two across the mountains, but outside of
that the forecast will stay dry. The caveat remains the potential
for any MCS activity that develops to the northwest and how that
propagates but predictability is still very low. Northerly flow will
certainly keep temperatures cooler, more aligned with climatological
normals.

Chances for precipitation begin to increase late Wednesday
associated with a passing disturbance aloft. With high pressure
moving off toward the east, southerly flow will increase bringing
better moisture back into the area. By late this week and into the
weekend, an area of low pressure is progged to lift into the Great
Lakes bringing a cold front through or near the area. This will
provide additional chances of showers and storms.

&&

.AVIATION...
(18Z TAFS)
Issued at 137 PM EDT Sat Jul 29 2023

Increasing chances of thunderstorms this afternoon and evening,
especially for TRI. VFR conditions at CHA through the period. VFR
at TYS except for a tempo MVFR due to this evenings storms. TRI
will begin VFR, then tempo MVFR with the afternoon/evening
storms. TRI will likely see fog tonight due the expected
rainfall with IFR conditions expected late, then a TEMPO for
exceeding runway minimums due to VIS tomorrow morning.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             96  74  94  71 /  10  30  30  10
Knoxville McGhee Tyson Airport, TN  94  72  91  69 /  40  40  20  10
Oak Ridge, TN                       94  72  90  68 /  40  40  20  10
Tri Cities Airport, TN              92  69  87  65 /  80  50  20  20

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&

SHORT TERM...
LONG TERM....
AVIATION...

Hazardous Weather Outlook
National Weather Service Morristown TN
318 PM EDT Sat Jul 29 2023

NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002-
005-006-008-301930-
Cherokee-Clay-Scott TN-Campbell-Claiborne-Hancock-Hawkins-
Sullivan-Johnson-Morgan-Anderson-Union-Grainger-Hamblen-
Northwest Cocke-Cocke Smoky Mountains-Northwest Greene-
Southeast Greene-Washington TN-Unicoi-Northwest Carter-
Southeast Carter-Roane-Loudon-Knox-Jefferson-Northwest Blount-
Blount Smoky Mountains-North Sevier-Sevier Smoky Mountains-
Sequatchie-Bledsoe-Rhea-Meigs-McMinn-Northwest Monroe-
Southeast Monroe-Marion-Hamilton-Bradley-West Polk-East Polk-Lee-
Wise-Scott VA-Russell-Washington VA-
318 PM EDT Sat Jul 29 2023 /218 PM CDT Sat Jul 29 2023/

This Hazardous Weather Outlook is for portions of southwest North
Carolina...east Tennessee and southwest Virginia.

.DAY ONE...This Afternoon and Tonight

A few to several strong to severe storms are expected this
afternoon/evening. Greatest chances will be along I-40 and
northward, especially across northeast TN and southwest VA.

Main threats will be isolated damaging wind gusts and localized
flooding due to heavy rainfall.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not needed at this time.

<!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>

<!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>