Area Forecast Discussion
Issued by NWS Lake Charles, LA

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221
FXUS64 KLCH 151738
AFDLCH

Area Forecast Discussion
National Weather Service Lake Charles LA
1238 PM CDT Tue Sep 15 2026

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

.KEY MESSAGES...

- High pressure centered over the northern Gulf Coast will limit
daily thunderstorm potential (20-30%) this week.

- Drier air will move into the region Thursday and Friday which will
lower heat indices and make conditions feel more comfortable.

- Precipitation chances increase Sunday into early next week as an area
  of low pressure moves into the northeastern Gulf.

&&

.DISCUSSION...
(This evening through next Monday)
Issued at 1237 PM CDT Tue Sep 15 2026

Scattered fair weather cu and a few thunderstorms have
already initialized across the region early this afternoon in what
remains a very tropical airmass (observed pwat of 2.2 on the 00Z
KLCH ob). Inhibiting substantial convection this afternoon will be a
steadily building upper level ridge presently centered over eastern
Tennessee and northern Georgia, but retrograding westward toward the
northern gulf coast. With that in mind, afternoon PoPs are
maintained on the low end at 20-30%. At the surface, a weak pressure
gradient will keep winds light and variable at 5 MPH or less through
the day. Guidance is again indicating a greater than 50% chance of
some patchy, light fog development early Wednesday morning in the
calm winds and clear skies. Some patchy fog was observed this
morning and with no material change in airmass or forecast
philosophy, persistence lends prudence to keeping it in the
forecast.

A weak upper level impulse is expected to progress across the
northern gulf from east to west Wednesday around the southern
periphery of the building upper level ridge over the southeastern
U.S. carrying even higher moisture (hard to make that statement with
pwats already at 2.2). This impulse is expected to offer some
thunderstorms across the lower atchafalaya basin to the coast, bu
the majority of the precipitation is should remain offshore closer
to the trough axis.

Behind this impulse, noticeably drier air will advect into the region
Thursday through Saturday bringing the apparent temperature and
actual temperature differential to within about five degrees of one
another. It will certainly still be hot, but noticeably less
oppressive after months of dewpoints in the upper 70s.

The forecast heading into early next week is still somewhat muddied,
by the evolution of a large, nontropical, upper level low that most
guidance brings across the Florida peninsula and into the northeast
gulf by Sunday. Some guidance brings the center of this low into the
northern gulf while others keep it over Florida. The track of this
low will have an outsize impact on precipitation chances from Sunday
through next Tuesday, but at a minimum, the tropical moisture will
push dewpoints back into the low to mid 70s for early next week.

Jones

&&

.AVIATION...
(18Z TAFS)
Issued at 1237 PM CDT Tue Sep 15 2026

VFR conditions will prevail through the period. Fair
weather cu will continue to develop through the afternoon and early
evening before dissipating after 01Z. Upper level ridging building
across the region will keep precipitation chances limited to 20-30%
so do not expect significant impacts from these. Winds will calm
overnight allowing for some patchy, light fog to develop between 09Z
and 12Z Wednesday morning. Any fog that develops will dissipate no
later than 13Z with VFR conditions to prevail thereafter.

Jones

&&

.MARINE...
Issued at 1237 PM CDT Tue Sep 15 2026

High pressure over the northern Gulf will keep winds out of
the south to southeast at 5-10 kt through tonight with seas of 1-2
feet. A disturbance moving through the area Wednesday will
strengthen easterly winds to 20-25 kt and increase wave heights to
near 8 feet. Small craft advisories will likely become necessary for
the Wednesday into Thursday time period.


&&

.FIRE WEATHER...
Issued at 1237 PM CDT Tue Sep 15 2026

A moist airmass remains in place over the region
with winds generally light out of the south to southeast. Most of
the area will remain dry through Wednesday, though an isolated
afternoon shower or thunderstorm cannot be ruled out. Afternoon
MinRH will be 40-50 percent inland and 50-60 percent near the coast.
For Thursday into the start of the weekend, drier air will begin to
move into the CWA, with afternoon MinRH decreasing to 30-40 percent
inland and 40-50 percent near the coast. East winds around 5-10 kt
are expected for this period.

&&

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

$$

PUBLIC/FIRE/MARINE...66
AVIATION...66