841
FXUS64 KLCH 040535
AFDLCH

Area Forecast Discussion
National Weather Service Lake Charles LA
1235 AM CDT Sun Oct 4 2026

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

.KEY MESSAGES...

- Rain chances continue Sunday as an upper level trough, weak surface
  boundary, and tropical wave all merge into a very moist air mass
  over the region.

- There is some potential for heavy rainfall on Sunday, especially
  over lower Acadiana and the Atchafalaya Basin where the best
  moisture and lift will be located.

- Lower rain chances are expected for most of the work week as
  drier pushes in Sunday night.

&&

.DISCUSSION...
(This evening through next Friday)
Issued at 327 PM CDT Sat Oct 3 2026

Latest SFC analysis showed a quasi-stationary frontal boundary
stretching along a line from near Natchez, MS to Houston, TX.  The
MSTR pooling along and ahead of this boundary is quite impressive,
with the KLCH 00Z RAOB sampling a PWAT of 2.57 inches, which exceeds
the daily max. Farther south, a broad area of low pressure was noted
over the SW Gulf, imparting a generally easterly flow across areas
south of the front and the Gulf waters.  The pattern aloft is quite
messy, with an upper low over the Bay of Campeche, a ridge over the
SE CONUS, and an upper trof axis stretching NE to SW across the
TX/OK panhandles into northern MX.

Radar imagery this evening has depicted mostly isolated showers and
the occasional thunderstorm drifting westward in the low to mid
level easterly flow across the area, despite the abundant MSTR and
adequate instability. Nebulous/weak forcing for ascent seems to be
the primary reason for the overall lack of activity, and examining
latest model progs does not offer much of a reason to believe that
will change significantly. While the upper trof to the west is
expected to translate EWD, it will be weakening as it does so, doing
just enough to get the front and associated deep MSTR pool offshore.
There will be a period tomorrow afternoon/evening when the boundary
sharpens across lower Acadiana, and this may help focus more
robust/sustained convection in this area. Otherwise, expect that the
isolated/scattered nature will continue until a drier airmass pushes
in SUN night.

For the rest of the work week, high pressure will settle in just
north of the area, with an easterly low level flow prevailing
underneath westerly flow aloft.  Deep MSTR will remain lurking just
offshore, keeping rain chances near the coast and over the Gulf
waters. Temperatures will be near or slightly above seasonal normals.
Forecast uncertainty increases Friday and into next weekend with the
approach and evolution of an upper level low, but the increasing
rain chances shown by the NBM are reasonable.

&&

.AVIATION...
(06Z TAFS)
Issued at 1229 AM CDT Sun Oct 4 2026

MVFR CIGS are starting to gradually fill in while radar continues
to show mainly isolated showers. Still low confidence in the
temporal and spatial details of convection the rest of tonight and
on Sunday, so didn`t make many changes from the 00z package in
that regard. Since the lowering CIGS seem to be playing out about
as forecast, generally preserved the previous forecast for the
coastal terminals as they are expected to persist here into SUN
evening while introducing an improvement to VFR at KAEX late
evening.

&&

.MARINE...
Issued at 1229 AM CDT Sun Oct 4 2026

Moderate northeast winds and moderate seas are expected through the
weekend as multiple disturbances approach the area. Winds of 10-20
kt and seas 2-5 feet are anticipated through the weekend, and small
craft are urged to exercise caution. Numerous showers and
thunderstorms are also expected through this time and will cause
locally higher winds and waves. Modest northeast winds will persist
through the rest of the week.

&&

.FIRE WEATHER...
Issued at 1229 AM CDT Sun Oct 4 2026

A very moist airmass will continue across the area through Sunday,
with afternoon minimum RH values in the 65 to 75 percent range. Good
rain chances also persist along and ahead of a weak, slow moving
frontal boundary draped across the area. This boundary will push
south of the area Sunday night, with relatively drier air moving in
on Monday. Dry weather will persist the rest of the week.

&&

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

&&

$$

PUBLIC/FIRE/MARINE...13
AVIATION...13