106
FXUS64 KLCH 171146
AFDLCH

Area Forecast Discussion
National Weather Service Lake Charles LA
646 AM CDT Mon Jun 17 2024

...New AVIATION...

.SYNOPSIS...
Issued at 445 AM CDT Mon Jun 17 2024

Latest IR and WV imagery shows copious tropical moisture streaming
northward across the Gulf of Mexico from a disturbance located
near the Bay of Campeche. KLCH radar shows a few showers already
developing over the coastal waters as well as portions of SW LA
early this morning, as energy associated with the system spreads
over the NW Gulf. This disturbance will be the main player in our
weather through at least midweek, and NHC continues to monitor
for possible development of a depression or storm.

In the meantime, as moisture increases and deepens over the
region, so will shower coverage with the potential for heavy
rainfall at times the next few days. At the coast, tide levels
have already begun to rise in response to the strengthening east
to southeast wind field. A Coastal Flood Advisory was issued for
our coastal parishes and county yesterday, but given the potential
for some significant flooding, especially along the Jefferson
County and western Cameron Parish coastlines, a Coastal Flood
Watch has now been issued.

24

&&

.SHORT TERM...
(Today through Wednesday night)
Issued at 445 AM CDT Mon Jun 17 2024

The trough/low will continue to take shape today in the Bay of
Campeche, and could become the first potential tropical cyclone of
the 2024 season. As the system develops, deep southeast to south
flow will continue to usher tropical moisture over the region,
with PWATs increasing to around 2.2 inches. The combination of
this moisture, minimal capping and ascent provided by an inverted
trough in the midlevels will allow showers and a few storms to
become more numerous across the region. With PWATs already well
above the 90th percentile and deep moisture profiles indicated on
forecast soundings, any showers or storms will be capable of very
efficient rainfall resulting in locally heavy downpours. WPC
continues to outline much of the area in a Slight Risk (level 2
out of 4) for excessive rainfall that could lead to localized
flooding. CAM guidance suggests some isolated spots could receive
3 to 4 inches of rain today.

A slight reprieve from the convection will be possible this
evening and overnight as instability weakens with the loss of
daytime heating, with nocturnal convection developing overnight
and moving toward the coastal areas early Tuesday morning. By
Tuesday however, a deeper slug of moisture will spread into the
region, with PWATs potentially as high as 2.5 inches (or possibly
greater) spreading into SE TX and far SW LA as the midlevel trough
approaches the TX coast. The latest WPC QPF has backed off some
on storm total rainfall amounts (compared to yesterday morning),
with a shift in the higher totals to the southwest. Despite this,
efficient warm rain processes will still be in play and would
support torrential downpours in any showers or storms that
develop. A Moderate Risk (Level 3 out of 4) remains in place for
portions of far SW LA into lower SE TX for excessive rainfall.
Given the recent shift in higher rainfall totals to the southwest
(which is reflected in global model guidance as well), have opted
to hold off on issuance of a Flood Watch at this time.

While flooding from rainfall may not be quite as widespread as it
appeared a few days ago, the risk for coastal flooding remains a
strong likelihood as the prolonged and strong east to southeast
fetch will bring increased water levels. The latest P-ETSS
guidance suggests tide levels could rise to between 2 and 3 FT
MHHW at Texas Point and between 1.5 and 2.5 FT MHHW at Calcasieu
Pass at times of high tide between Tuesday and Wednesday. While
there remains some spread in guidance ensembles, these values
remain fairly consistent from yesterday morning. Because of this,
have gone ahead and issued a Coastal Flood Watch for the Jefferson
County and Cameron/Vermilion Parish coasts.

The low pressure system will continue to move slowly west to west
northwest from Tuesday into Wednesday, approaching the coast of NE
Mexico Wednesday night. The bulk of the moisture and energy
associated with the system will shift westward into TX, with
slightly drier air beginning to filter into the region from the
east. Another day of scattered to numerous showers and storms is
expected on Wednesday, and the excessive rainfall outlook for Day
3 continues to show at least a Slight Risk for portions of SE TX,
with a Marginal Risk extending into SW LA.

During this timeframe, daytime temperatures will be cooler than
normal thanks to widespread clouds and showers, and temperatures
on Tuesday could struggle to reach the middle 80s.

24

&&

.LONG TERM...
(Thursday through Monday)
Issued at 445 AM CDT Mon Jun 17 2024

Gulf of Mexico disturbance and its associated large envelop of
moisture expected to be well inland Mexico/Texas by Thursday
morning, as the large mid to upper level ridge of high pressure
builds over the Gulf and Southeastern U.S. states. Lingering
moisture will still be available for scattered showers and
thunderstorms along and south of the I-10 corridor through Saturday,
with the best chances across the coastal waters. With the ridge of
high pressure nearly overhead, afternoon temperatures in the lower
90s expected for Thursday, and mid 90s for Friday and Saturday. Lows
in the lower to mid 70s.

Sunday and Monday a little less confidence in the precipitation
forecast, with the lingering Gulf moisture possibly moving northward
as the mid to upper level ridge weakens and a weak broad mid to
upper level trough prevails over the Central U.S. Blended guidance
shows 30-50% inland for Sunday, and 40-60% for Monday, mainly during
the afternoons. Highs in the lower to mid 90s, and lows in the mid
to upper 70s.

08/DML

&&

.AVIATION...
(12Z TAFS)
Issued at 639 AM CDT Mon Jun 17 2024

Messy aviation conditions will be unfolding through the day today
as SHRA/TSRA increase across the area. This activity will be
accompanied by lower vsbys and cigs, as well possibly +RA and
brief wind gusts. Outside of any convection, VFR conditions should
prevail with E to SE winds 8-12 KT. Winds could be a little higher
near BPT with gusts between 20-25 KT at times this afternoon.
Convection should begin to diminish after sunset, with cigs
lowering to MVFR after 06Z.

24

&&

.MARINE...
Issued at 445 AM CDT Mon Jun 17 2024

A tropical disturbance in the southwestern Gulf of Mexico will
gradually move west-northwest toward the northeast Mexico coast
through Wednesday. Deep moisture will be associated with this
system that will bring widespread shower and isolated thunderstorm
activity.

A strengthening gradient between the disturbance and
high pressure to the northeast will generate moderate to strong
east to southeast winds through mid week. The prolonged fetch
will allow for a significant increase in wave heights and swells,
as well as an increased risk for coastal flooding. Small Craft
Advisories are in effect across the coastal waters. Offshore seas
between 10 to possibly 15 feet will be possible from Tuesday into
Wednesday, with occasional gusts to gale force. Mariners are
encouraged to monitor the latest forecasts.

24

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  87  72  84  72 /  80  30  50  20
LCH  85  74  82  74 /  80  30  80  50
LFT  87  76  84  76 /  90  40  70  30
BPT  88  76  84  75 /  80  40  80  60

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...Coastal Flood Watch through Wednesday evening for LAZ073.

     Coastal Flood Watch from this evening through Wednesday evening
     for LAZ074-252.

     Coastal Flood Advisory from 7 PM this evening to 7 PM CDT
     Wednesday for LAZ253-254.

TX...Coastal Flood Watch through Wednesday evening for TXZ615.

GM...Small Craft Advisory from 1 PM this afternoon to 7 AM CDT
     Thursday for GMZ450-452-455-470-472-475.

&&

$$

SHORT TERM...24
LONG TERM....08
AVIATION...24