Flash Flood Warning 15, NWS Lake Charles, LA

Area Forecast Discussion
National Weather Service Lake Charles LA
326 AM CST Thu Jan 25 2024

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

.UPDATE...
Issued at 935 PM CST Wed Jan 24 2024

Our long awaited rain event continues this evening as another
round of mainly light rain ahead of an approaching disturbance
aloft shrouds much of the forecast area. Not surprisingly, the 00z
KLCH sounding showed a very moist airmass lingering with a PWAT
value approaching 1.6 inches (nearly a daily max per SPC climo)
while mean RH values were at or slightly less than 90 percent
(which frankly is a bit surprising). In addition, local 88Ds are
showing a cluster of elevated thunderstorms moving across our swrn
coastal zones at this time. Meanwhile, our next round of
potentially heavy precip is showing up on regional 88Ds out over
cntl TX, poised to move into the forecast area during the
overnight hours. All in all, there's really nothing to add to
what's already in the grids/zones, so no updates are planned as
far as precip.

However, latest high res fog guidance indicates the potential for
dense fog development over the far sern zones as a weak sfc low is
progged to develop over the nwrn Gulf through the night, then
track newd...the srly flow ahead of it looks likely to push the
ongoing marine fog nwd into these areas after midnight. Thus, am
planning to issue a Dense Fog Advisory for this small area
shortly. Guidance gets a little wishy washy as far as how far
inland or wwd the fog could go...parishes on the edge of the
advisory area could certainly see deteriorating conditions at
some point overnight and the advisory could be expanded if
necessary.

Elsewhere, remaining grids/zones look in fine shape as is per
recent obs/trends/guidance.

Update out shortly. Stay dry, everyone.
25

&&

.SHORT TERM...
(Today through Saturday night)
Issued at 310 AM CST Thu Jan 25 2024

A subtropical high pressure positioned east of the Bahamas with a
fairly wide shortwave over the central/western CONUS has provided a
frontal boundary acting a as conveyer belt supplying smaller
disturbances along the leading edge of the upper level trough.
Presently, a low pressure trough is shifting east near ARKLATEX
region and a stationary boundary extends from the eastern Great
Lakes SWW across the LA/TX coast. The rather non-uniform shortwave
across the western 2/3rds of the CONUS begins to modify through this
evening with the downstream portion beginning to amply a slight
negative tilt toward TX, thus ushering the boundary west of the CWA
by tonight. In the meantime, appropriate flood hazards and watches
remain in effect. Additional river flooding and ponding on low lying
or flood prone areas will remain possible into Friday and Saturday
as drainage basins to the north work towards the coast. Fog will
remain a hazard that we’ll periodically see into the weekend with
cooler waters near the coast and wet surfaces inland and some
potential WAA toward the coast through Friday night.

Although the hazardous rainfall is expected to shift east by this
evening, as mentioned above, WAA and weak surface troughing attempt
to lift northward along the western Gulf into southern LA/TX. The
stationary boundary will lift from the coast forming a weak surface
low along Eastern LA and SW MS Friday evening. Therefore Isolated to
scattered showers with potential of some thunder can be expected
starting the mid morning Fri. into predawn hours Saturday morning.
Meanwhile, the aforementioned wide shortwave is now expected to
accelerate east toward the western Ohio Valley with a mid- level
trough over SE OK. Both features will attempt to merge during the
course Friday afternoon / night. Hereafter, the sfc low deepens
and also accelerates over the SE CONUS into Sunday morning which
lets the remainder of Saturday dry out west to east with some CAA
from the NW.

Kowalski/30

&&

.LONG TERM...
(Sunday through Thursday)
Issued at 310 AM CST Thu Jan 25 2024

By Sunday, expect much cooler daytime highs with breezy NW flow.
Daytime high temps will be in the upper 50s to around 60 degrees for
the entire area. For the rest of the week, SFC high pressure builds
into the region with a slow warming trend. Daytime highs will
gradually climb a degree or two each day with temps approaching 70
degrees late week. There could be another weather system that moves
throgh the region for the weekend, but confidence is low at this
time.

78

&&

.AVIATION...
(06Z TAFS)
Issued at 1139 PM CST Wed Jan 24 2024

Messy aviation forecast through roughly the next 12 hours as
periods of SHRA will prevail with occasional TS. Radar currently
shows a band of convection crossing SW LA, with activity near
KLCH. Additional bands are noted across S central LA, with
moderate RA across central LA. Further west over SE TX, the next
round of SHRA/TSRA is developing and will be moving east across
the area later tonight. Timing remains similar to previous TAFs
with this last band of convection expected between ~09Z to ~16Z.
VFR cigs held on longer than expected this evening, but IFR/LIFR
cigs are beginning to form and should become widespread over the
next couple of hours, while vsbys will fall to MVFR/IFR during
periods of heavier SHRA. Once the last band of convection moves
through later tonight into Thursday morning, winds will shift
northwest to north, with gradually improving conditions expected
after 18Z Thursday. Some patchy fog could return toward the end of
the TAF period.

24

&&

.MARINE...

Patchy to areas of dense fog will continue for the near shore
waters, lakes, and bays as warm and moist air continues over the
very cold shelf waters. The dense fog is expected to continue
through early Thursday morning. Otherwise, a large upper level
trough over the Western U.S. will send periodic disturbances that
will keep high chances of showers and thunderstorms across the
region through Friday night. The next cold front expected to move
through Saturday morning, bringing an end of the rainfall and
offshore flow for the weekend.

08/DML

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  70  50  68  57 /  90  20  40  80
LCH  70  54  69  58 /  90  30  50  80
LFT  72  60  73  63 /  90  50  70  80
BPT  72  54  70  58 /  60  30  40  70

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...Flood Watch until noon CST today for LAZ027>033-044-045-055-073-
     074-141>143-152>154-241>243-252>254.

     Dense Fog Advisory until 8 AM CST this morning for LAZ055-153-
     154-253-254.

TX...Flood Watch until noon CST today for TXZ180-201-259>262-515-516-
     615-616.

GM...Dense Fog Advisory until 9 AM CST this morning for GMZ430-432-
     450-452.

     Dense Fog Advisory until noon CST today for GMZ435-436-455.

&&

SHORT TERM...30
LONG TERM....78
AVIATION...24

<!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>