Area Forecast Discussion
Issued by NWS Lake Charles, LA

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762
FXUS64 KLCH 300525
AFDLCH

Area Forecast Discussion
National Weather Service Lake Charles LA
1225 AM CDT Sun Aug 30 2026

...New DISCUSSION, AVIATION, MARINE, FIRE WEATHER...

.KEY MESSAGES...

- Flow around an upper level high will allow for drier air in the mid
  levels to help keep showers and thunderstorms today isolated.

- As the upper level high moves to the north, a tropical wave will move
  across the region on Monday and Tuesday with elevated rain
  chances and some potential for torrential downpours.

- A broad weakness in the mid levels will remain over the area
  through the week with a series of inverted troughs and high
  moisture keeping a decent chance for daily scattered showers and
  thunderstorms with normal summertime heat.

&&

.DISCUSSION...
(Today through Saturday)
Issued at 1225 AM CDT Sun Aug 30 2026

Weather analysis shows a broad upper level ridge stretched from the
southwest US to the Tennessee Valley helping to provide subsidence
aloft with a dry northeast flow. Meanwhile, an inverted trough
feature in the northeast Gulf with a weak surface low about a 100
miles south of the Mississippi coast along with some deeper tropical
like moisture that has been designated by NHC as AL97, is moving
slowly to the west.

Over the next few days, the upper level ridge will shift to the
north and weaken. The inverted trough/tropical wave will move
westward along the northern Gulf coast with the associated surface
low near or inland of the coast. Consensus of guidance keeps
wherever the surface low moves, weak with a better representation
of this feature at 70H and 50H. Currently, NHC has a 20 percent
chance that this system AL97 will develop into tropical cyclone.

For today, with the northeast flow keeping that dry subsident flow
over the forecast area, shower activity should continue to be
isolated in nature and mainly along the sea breeze boundary in the
late afternoon.

On Monday, the inverted trough/tropical wave is expected to slip
underneath the upper level ridge and move into the forecast area.
The deeper moisture is expected to arrive in the afternoon with PWAT
values in the 2.25 to 2.50 inch range with mean layer relative
humidity from 100H-50H above 80 percent, with the higher values near
the coast closer to the upper level or surface low wave. Daytime
heating at that time along with an enhanced sea breeze as flow
begins to become more from the southeast will allow for widespread
showers and thunderstorms to develop by mid to late afternoon. With
the high moisture values and tropical like air mass with warm cloud
layers around 15k feet, some tropical downpours with high rain rates
in a short period will be possible, especially closer to the apex of
the wave, which will likely be along and south of the I-10 corridor
and WPC has a majority of the area outlined in a Marginal (level 1
out of 4) Risk for excessive rainfall.

On Tuesday, the inverted trough/tropical wave feature will move
inland and be somewhere between southeast Texas and western
Louisiana. With a predominate southeast flow in the low levels
keeping high moisture values in place, widespread showers and
thunderstorms will be possible with daytime heating and the sea
breeze.

For the remainder of the week, a broad weakness is expected to be
located over the region and this will a series of inverted troughs
to move across and good Gulf moisture to remain in place. Therefore,
a daily chance for mainly scattered afternoon showers and
thunderstorms will continue along with normal summertime heat.

07/Rua

&&

.AVIATION...
(06Z TAFS)
Issued at 1225 AM CDT Sun Aug 30 2026

Stable conditions are expected through the night with light winds
and mainly clear skies. Some shallow ground fog will be possible
and will mention some MVFR conditions because of this, otherwise
VFR conditions will prevail. Sunday looks like a repeat of recent
days with some isolated pop up showers along the seabreeze with
max heating. Will place VCSH at southern terminals to account for
this. Otherwise, VFR away from the convection.

07/Rua

&&

.MARINE...
Issued at 1225 AM CDT Sun Aug 30 2026

Light and variable winds with low seas are expected today with just
isolated showers and thunderstorms as weak high pressure will be in
place. A tropical wave will move across the coastal waters on Monday
and Tuesday. Winds will become more southerly with modest gusts as
the wave moves across along with more widespread shower and
thunderstorm activity.


&&

.FIRE WEATHER...
Issued at 1225 AM CDT Sun Aug 30 2026

Some drier air, especially above the surface will persist today
keeping rain chances isolated and minimum afternoon relative
humidity values at modest levels between 40 and 50 percent.

A tropical wave will move across the region on Monday and Tuesday
helping to increase moisture. Minimum afternoon relative humidity
will range between 50 and 70 percent with showers and thunderstorms
becoming more widespread. There is the potential for some torrential
downpours, mainly south of the I-10 corridor, providing some much
needed rainfall as KBDI values are in the 500 to 750 range.

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...None.
TX...None.
GM...None.
&&

$$

PUBLIC/FIRE/MARINE...07
AVIATION...07