421
FXUS64 KLCH 171622
AFDLCH

Area Forecast Discussion
National Weather Service Lake Charles LA
1122 AM CDT Thu Sep 17 2026

...New AVIATION...

.KEY MESSAGES...

- A weak trough will migrate below the Louisiana coastline today
  enhancing winds/seas offshore but chances of precipitation
  inland will be hindered due to northerly dry air.

- Drier air will remain across the region, today through Saturday
  which will keep heat indices below advisory criteria.
  Temperatures will still range 5-10 degrees above climatological
  norms for the end of Summer.

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

&&

.DISCUSSION...
(Today through Wednesday)
Issued at 1200 AM CDT Thu Sep 17 2026

Wx map currently features elongated high pressure extending SW of
the appalachians into the Mississippi Valley while broad surface
ridging remains over the western Gulf Coast. Abutting the ridge
pattern is a shallow trough migrating east below the Louisiana
coastline. Normally, coastal troughs pose higher chances for
precipitation inland, however, dry air from the northeast will
prevent much activity from organizing north of the immediate coast.
Conditions inland will remain relatively dry and hot with
temperatures hedging into the upper 90s across interior Southeast
Texas and central Louisiana. The coastal trough will dissipate over
the upper Texas coastline into early Friday with winds / seas
gradually easing and abating through the morning. Dry weather
continues Friday into the weekend with the mid and upper levels
filtering in the less humid continental air.

By Sunday, the forecast begins to shifts back to widely spread low
end chances for precipitation into the following week. An upper
level closed low will follow the late summer easterly trades across
Florida peninsula. There is some disagreement whether or not the
feature will remain closed or open to broader wave / disturbance
which could pull in higher moisture toward the end of the forecast
period. In the meanwhile, Monday, temperatures are forecast to hold
in the mid 90s with the exception of the coastal parishes and
counties. Barometric pressure will drop as the previous ridge
pattern breaks down through Tuesday while troughing deepens at the
surface, broadly across the Gulf. The present forecast trends keep
modest northerly upper level flow with mostly easterly low level
flow above the surface. For interior locations above the I-10
corridor, that is not very promising for better rainfall potential
given poor effective inflow. However, we are speaking six to seven
days out trending into the middle of next week which keeps similar
temperatures and chances for precipitation in the forecast. Thus, I
will caveat there is room for the upper air pattern to adjust better
moisture into Southwest Louisiana and Southeast Texas with the
analysis of subsequent data.

 Kowalski / 30

&&

.AVIATION...
(18Z TAFS)
Issued at 1121 AM CDT Thu Sep 17 2026

VFR conditions with generally east winds will prevail during the
period.

&&

.MARINE...
Issued at 1200 AM CDT Thu Sep 17 2026

A fairly tight pressure gradient will keep easterly winds elevated
through this evening. Winds will slowly decrease into Friday and
through weekend as high pressure moves off the Atlantic coast. As
per recent forecast, the Small Craft Advisory has been adjusted to
continue offshore east of Cameron, LA until 1AM CDT Friday where
offshore winds / seas will remain slower to ease and abate.

&&

.FIRE WEATHER...
Issued at 1200 AM CDT Thu Sep 17 2026

Dewpoints will lower today and Friday as a drier airmass filters in.
Relative Humidity values may fall into the 30s across interior areas
through Saturday. Chances for precipitation do increase early next
week, but only to conditional and low end isolated chances as some
low level moisture works its way back onshore.

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...None.
TX...None.
GM...Small Craft Advisory until 7 PM CDT this evening for GMZ450-470.

     Small Craft Advisory until 1 AM CDT Friday for GMZ452-455-472-
     475.

&&

$$

PUBLIC/FIRE/MARINE...30
AVIATION...05