692
FXUS64 KLCH 021146
AFDLCH

Area Forecast Discussion
National Weather Service Lake Charles LA
646 AM CDT Fri Oct 2 2026

...New AVIATION...

.KEY MESSAGES...

- Rain chances increase into the weekend as an upper level ridge
  will be replaced with an upper level trough and a surface
  boundary.

- There will be an increase in the potential for heavy rainfall over
  the weekend as the upper level trough and frontal system meet
  up with tropical moisture and slowly move across.

- Onshore flow combined with larger than normal tide ranges will
  result in areas of minor coastal flooding through Friday
  morning.

- A secondary surface front on Monday will bring lower rain
  chances and slightly cooler temperatures closer to the climo
  norm for early next week.

&&

.DISCUSSION...
(Today through Thursday)
Issued at 1248 AM CDT Fri Oct 2 2026

Evening water vapor satellite imagery and upper air analysis depict
a broad upper level ridge encompassing most of the southeast,
centered off the NC Atlantic coast. To our northwest, the upper
level closed low has opened up into a positively tilted trough
currently located over west Texas into the central Plains. At the
surface, a trough and frontal boundary currently extend north-south
through central Texas, with rich moisture sourced from the tropical
Eastern Pacific, while weak high pressure currently dominates the
eastern third of the CONUS.

The resulting southeasterly flow over our CWA continues to stream
Gulf moisture into the area, with surface dewpoints in the mid to
upper 70s. PWAT values have continued to climb and currently sit in
the 1.9 to 2.1 inch range per the 00z LCH RAOB and RAP analysis.
With this moist air in place, some patchy mist or light fog cannot
be ruled out late tonight for inland areas where skies clear. This
should dissipate with daybreak.

The other impact of this southeast flow, combined with larger than
normal tide ranges, will be elevated water levels along the Gulf
coast and Sabine and Calcasieu Lake shores. Impacts should remain
minor, but guidance shows water levels reaching up to 1.5 feet above
MHHW for tonight`s high tide cycle. As a result, a coastal flood
advisory has been issued for these areas through tomorrow morning.

As the upper trough lifts off to the northeast, it will leave a
weakness that will allow for greater coverage of convection over our
area. Isolated showers are expected to develop over the Gulf
overnight and may spread into coastal areas as early as sunrise
Friday morning. Coverage and intensity of this convection should
increase with diurnal heating, and scattered showers and
thunderstorms are expected through the afternoon hours. With little
shear to speak of, storms will be of the pulse variety, and should
dissipate with sunset as instability wanes. Outside of convection,
temperatures will reach the mid 90s, and with dewpoints in the low
to mid 70s, heat index values will push into the low 100s.

The weekend is expected to see an even stronger push of tropical
moisture from the Gulf as a wave rotates around an upper-level high
centered over Florida, while the frontal boundary slowly migrates
east through southeast Texas and Louisiana. The combination of
tropical moisture from both the Gulf and East Pacific will result in
a highly anomalous environment. LREF mean PWAT climbs to 2.4-2.5
inches for Saturday afternoon through Sunday, which is well in
excess of the daily maximum moving average. This is a very high
confidence forecast with practically the entire ensemble
distribution for PWAT exceeding climatological 99th percentile
through this period.

The primary concern with this setup will be the potential for storms
to produce very heavy rainfall with a threat for flash flooding.
Thermodynamic profiles will be favorable for highly efficient warm
rain processes as model soundings depict tall, skinny CAPE profiles,
mid-level RH in excess of 70-80 percent, and deep warm cloud layers
of 15 kft or greater. Storm motions will be slow, 10 kt or less,
which will further contribute to the flood threat. However, a number
of uncertainties still linger with respect to the flash flood
potential. The degree of instability is particularly uncertain as
what will likely be widespread morning cloud cover may limit
destabilization, with spreads from around 500 to 1100-1200 J/kg in
the 25th-75th percentiles of the 00z HREF. There is also uncertainty
in the position of the better upper-level forcing, which may
maximize more towards southeastern Louisiana, south and east of the
CWA, and result in less intense rainfall rates and lower flood
potential.

One mitigating factor for any flooding potential will be dry
antecedent conditions. With the exception of a few areas in
southeast Texas, almost all of the CWA is currently analyzed in
moderate or severe drought, and the dry soils will likely be able to
absorb quite a bit of moisture. That said, given the potential for
very heavy rainfall rates, flash flooding will be a concern, with
urban and poorly drained areas most at risk.

The flash flood threat will be greatest for areas to the southeast
of the surface frontal boundary, where moisture will be maximized
and upper-level forcing will be more favorable, though with such
rich tropical moisture in place, any thunderstorm that develops will
need to be watched. WPC currently carries a Slight risk (level 2/4)
for excessive rainfall on Saturday generally along and south of the
US 190 corridor, with the remainder of the CWA in a Marginal (level
1/4) risk. For Sunday, as the front shifts southeast, the highest
risk will shift to areas south and east of Lafayette. These areas
are currently in a WPC Slight risk for that day, with the remainder
of the CWA in a Marginal risk. Forecast rainfall totals for the
Friday through Sunday time period generally range from 1 to 3
inches, with the highest totals in lower Acadiana. However, 90th
percentile (reasonable worst-case scenario) totals are much higher,
closer to 3-8 inches.

With the widespread cloud cover, rainfall, and frontal boundary, a
cooling trend is expected for temperatures over the weekend, with
high temperatures falling into the mid 80s while overnight lows stay
near 70.

A mid-latitude trough will dig into the northeastern CONUS for
Sunday into Monday, which should allow a secondary cold front to
push south through the CWA Monday into Tuesday. Much drier
conditions are anticipated in the wake of this front, along with
seasonable temperatures for early October.

64/Silas

&&

.AVIATION...
(12Z TAFS)
Issued at 626 AM CDT Fri Oct 2 2026

As a cold front over Central Texas slowly continues to track
eastward, scattered showers and thunderstorms are within the
vicinity of BPT and LCH. Additional scattered storms are expected
by 17Z with all sites prevailing VCTS. CAM guidance suggests that
coverage of these storms is likely to increase in the afternoon
and a tempo has been added from 19-23Z to account for this at BPT,
LCH, LFT, and ARA. Shower and thunderstorm activity is expected
to decrease following sunset. Winds will become variable and
remain below 6 kt, and VFR conditions are expected at all sites
overnight. BPT and LCH are expected to see winds establish
themselves from the northeast and increase to between 8-9 kt
shortly before the end of the period.

BN/56

&&

.MARINE...
Issued at 1248 AM CDT Fri Oct 2 2026

Southeast to east winds 10-15 kt will prevail for Friday through the
weekend, with seas generally in the 2-4 ft range. A very moist
airmass and approaching front will result in widespread showers and
thunderstorms through this time period. The front will push off to
the south to begin next week with moderate to strong offshore flow
developing in its wake.

&&

.FIRE WEATHER...
Issued at 1248 AM CDT Fri Oct 2 2026

A moist, tropical-like air mass is currently in place over the CWA,
with scattered thunderstorms expected to develop Friday. Afternoon
minimum RH values will generally range from 45 to 65 percent, with
winds staying at or under 10 kt. The weekend will see even more
tropical moisture move in, with afternoon minimum RH only dropping
to around 80 percent. Widespread wetting rainfall is expected, which
may allow for at least some improvement in drought conditions across
the region.

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...Coastal Flood Advisory until 7 AM CDT this morning for LAZ073-
     074-252>254.

     Coastal Flood Advisory until 1 PM CDT this afternoon for LAZ241.

TX...Coastal Flood Advisory until 7 AM CDT this morning for TXZ615.

     Coastal Flood Advisory until 1 PM CDT this afternoon for TXZ616.

GM...None.
&&

$$

PUBLIC/FIRE/MARINE...64
AVIATION...56