970
FXUS64 KLCH 161143
AFDLCH

Area Forecast Discussion
National Weather Service Lake Charles LA
643 AM CDT Sun Jun 16 2024

...New AVIATION...

.SHORT TERM...
(Today through Tuesday night)
Issued at 414 AM CDT Sun Jun 16 2024

Today we will see a shift into a more active period with multiday
scattered to numerous PoPs and flooding potential. The upper ridge
that kept us unseasonably warm and dry has moved off, centering
itself over the Southeastern States. An inverted trough over the
southern gulf and its associated plume of deep moisture is spreading
over the Gulf and Gulf Coast States. This disturbance is expected to
move west over the period and there is a 60 percent chance of
development into a depression. Regardless of development, this
system will bring heavy rainfall and breezy conditions. Potential
threats include river/flash flooding, higher seas/tides, coastal
flooding.

Over the day, we will see an increase in PWATs as the plume of
moisture steadily moves westward. That along with diurnal processes
will be sufficient to get isolated to numerous showers and storms
kicked off during the late morning to evening hours. Forecast PWATs
along the coast and in the Acadiana region today are in the 1.8 to
2.2 inch range. Going into the work week, we could see near 2.7
inch PWATs. Rainfall totals just over the short term period area
in the 1- 4 inch range north of the I-10, with 4 to 8 inches south
of there. Locally higher amounts will certainly be possible.

As of now, there is a Slight (lvl 2 of 4) to Marginal Risk (lvl 1 of
4) of excessive rainfall every day of the short term with a Moderate
Risk (lvl 3 of 4) for Tuesday night into Wednesday morning. Keep in
mind that the potential for greater and or additional flood threats
will exist over this period.
Stigger/87

&&

.LONG TERM...
(Wednesday through Sunday)
Issued at 414 AM CDT Sun Jun 16 2024

Heavy rainfall and flood potential will remain a concern going into
Wednesday with an inverted trough aloft over the western Gulf of
Mexico and possible tropical cyclone over the SW Gulf. Deep SE to S
flow through the column from the SFC to above 500 MB will continue
to funnel an anomalously moist airmass over the region with PWAT
values of at least 2.5 or higher inches across portions of SE TX and
SW LA. The best likelihood for heavy rainfall will be confined to
far SW LA and SE TX as the trough and its associated surface feature
move west into TX and NE Mexico during the day. WPC has maintained a
Slight Risk (level 2 out of 4) for excessive rainfall on Day 4 (Wed
into Thu) although most of the risk will occur during the day
Wednesday. This will come on the heels of a Moderate Risk on Tuesday
and, depending on how conditions evolve, a Moderate Risk for parts
of SE TX could be warranted in upcoming outlooks.

Along the coast, a prolonged and strong easterly fetch will likely
produce elevated tide levels, especially along the Jefferson and
Cameron coasts. P-ETSS guidance ensembles suggest the potential for
significant coastal flooding early Wednesday although guidance
spread is still fairly large. At this time, deterministic values
suggest water levels between 2.5 and 3 feet above astronomical
predicted levels will be possible from Calcasieu Pass to Texas Point.

Conditions should begin to improve Wednesday night into Thursday as
a ridge axis aloft migrates into the region in the wake of the
tropical disturbance. PWATs, while elevated, should trend closer to
the daily mean at least for a day or two, and this should be
sufficient to produce some scattered and mainly diurnally induced
convection Thursday and Friday afternoon. Daytime highs should begin
to climb back to around 90 or into the lower 90s each afternoon as
coverage of clouds and showers decreases.

By next weekend, a similar scenario to what is expected in the short
term could start unfolding again as a tropical wave advances west
over the Gulf of Mexico aloft and lower pressure develops in the Bay
of Campeche. Rain chances are again expected to increase Saturday
into Sunday as another plume of tropical moisture advects into the
region.

24

&&

.AVIATION...
(12Z TAFS)
Issued at 639 AM CDT Sun Jun 16 2024

A swift pattern change will occur as showers and thunderstorms
begin to move into the are later today and into tonight. While
severe thunderstorms are not expected at this time, heavy rain
leading to reduced visibilities will be possible.
Stigger/87

&&

.MARINE...
Issued at 414 AM CDT Sun Jun 16 2024

A trough will gradually move west across the southern Gulf of
Mexico from early to mid week. Deep moisture will be associated
with this system that will bring widespread shower activity. The
gradient between the trough and high pressure to the northeast
will bring moderate to strong east to southeast winds at or above
20 knots going into tomorrow morning to afternoon that will
continue through mid week. This prolonged wind field will allow
for a significant increase in wave heights and swells. Small craft
advisories will likely be needed during this period. Also, tides
will be 1 to 2 feet above normal predicted levels that may lead to
coastal flooding.

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  94  72  86  71 /  20  20  90  20
LCH  91  75  86  75 /  50  50  90  50
LFT  91  76  86  76 /  80  50  90  40
BPT  93  77  87  76 /  30  40  90  50

&&

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

$$

SHORT TERM...87
LONG TERM....66
AVIATION...87