621
FXUS64 KLCH 171123
AFDLCH

Area Forecast Discussion
National Weather Service Lake Charles LA
623 AM CDT Thu Jul 17 2025

...New AVIATION...

.KEY MESSAGES...

- The Flash Flood Watch has been extended and now includes most of
  southwest Louisiana Thursday through Saturday.

- Heavy rainfall from a tropical disturbance will have the
  potential to produce rainfall totals of 1-6 inches Thursday
  through Saturday with amounts of up to 12 inches possible in a
  few locations across south central Louisiana.

- Heat returns to the region in the middle of next week with highs
  in the mid to upper 90s.

&&

.SHORT TERM...
(Today through Saturday night)
Issued at 1227 AM CDT Thu Jul 17 2025

Scattered showers and thunderstorms are located to the east in
southeast Louisiana and are associated with a weak tropical
disturbance over the northern Gulf. This system remains
unorganized, and additional strengthening is looking more unlikely,
with the NHC now giving the system a 30% chance of development.
Regardless of whether or not the system becomes named, the main
concern for our region will remain heavy rainfall and flash
flooding.

An Excessive Rainfall Outlooks are in place Thursday through
Saturday with a Moderate risk (level 3 of 4) in place for Friday,
when the bulk of the rain is expected. A large amount of tropical
moisture is in place with this system, and precipitable water
(Pwats) will rise above 2 inches, which would put Pwats into the
90th percentile. In addition, the GFS is highlighting the
possibility of record-breaking Pwat values over 2.4 inches across
southwest and central Louisiana. Ensemble tables from the ECMWF
support the GFS, showing Pwat values above the 99th percentile on
Friday and Saturday. Forecast sounding profiles are also
concerning for a flash flood setup, with "skinny" CAPE profiles
and high freezing levels that are favorable for efficient warm
rain processes. The range for rainfall totals remains consistent
from previous model runs, with widespread 2 to 6 inches and local
maximums up to 15 inches. Because of these factors, the Flood
Watch now extends across most of southwest Louisiana and now
includes Lake Charles.

&&

.LONG TERM...
(Sunday through Thursday)
Issued at 1227 AM CDT Thu Jul 17 2025

After the passage of the disturbance, our weather pattern will
return to summertime norms with weak ridging aloft. For the
extended forecast, PoPs will remain in the 20 to 30% range. Midway
through next week, the NBM has temperatures rapidly rising into
the mid to upper 90s, with heat index values well into the triple
digits. If this pans out then heat advisories should be expected
for next week.

&&

.AVIATION...
(12Z TAFS)
Issued at 619 AM CDT Thu Jul 17 2025

Shower activity (with a few embedded thunderstorms) associated
with Invest 93L will be the main issue through this forecast
period. This convection is beginning to spread across Acadiana
at this time, and should continue to spread slowly west and north
throughout today. For this most part this will be in the form of
mainly light to moderate rainfall however, a few areas of embedded
heavy downpours and/or thunderstorms are possible especially this
afternoon. Outside of heavy downpours, reductions in VIS should be
minimal with this precip. CIGs will largely maintain VFR, until
the overnight period when guidance begins to bring in some MVFR
and possibly IFR CIGS. Winds will be mainly light and variable
through the period, except near any thunderstorms which could
result in localized gusty winds.


&&

.MARINE...
Issued at 1227 AM CDT Thu Jul 17 2025

The tropical disturbance is not expected to produce much in the
way of wind, and sustained winds are expected to stay below the
20-knot threshold for a Small Craft Advisory. Exercise caution
headlines may be needed, but even that looks marginal right now.
Scattered thunderstorms and reduced visibility due to heavy
rainfall will be the main threats to mariners through the weekend.
Near thunderstorms winds and waves will be locally higher.
Background wave heights will be between 2 and 4 feet.

&&

.FIRE WEATHER...
Issued at 1227 AM CDT Thu Jul 17 2025

Soaking rain is expected area-wide Thursday through Saturday, with
widespread 2 to 6 inches of rainfall. Minimum RH values will
remain in the 40 to 60% range with light winds.

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  95  74  89  72 /  40  30  90  30
LCH  91  75  86  76 /  60  70  90  40
LFT  88  75  85  75 /  90  60  90  40
BPT  93  74  86  75 /  30  60  80  40

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...Flood Watch through Saturday evening for LAZ030>033-044-045-055-
     073-074-141>143-152>154-241>243-252>254.

TX...None.
GM...None.
&&

$$

SHORT TERM...14
LONG TERM....14
AVIATION...17