855
FXUS64 KLCH 180453
AFDLCH

Area Forecast Discussion
National Weather Service Lake Charles LA
1153 PM CDT Mon Jun 17 2024

...New AVIATION...

.SYNOPSIS...
Issued at 426 PM CDT Mon Jun 17 2024

Potential Tropical Cyclone Number 1 is expected to move westward
across the southern Gulf of Mexico and into eastern Mexico by
Wednesday night. The system is expected to overall stay on sloppy
and elongated side, and this will keep a rather large wind field
and moisture on the north side of the system. Therefore, portions
of the forecast area will have some impacts as far as heavy
rainfall potential and coastal flooding, and for the coastal
waters strong winds and hazardous seas.

A Flash Flood Watch will be in effect for lower southeast Texas
from Tuesday morning through Wednesday afternoon. Rainfall amounts
will be 2 to 5 inches with locally higher amounts, and also what
may be more concerning will be the rainfall rates up to 2 inches
per hour that will quickly cause urban and street flooding.

A Coastal Flood Warning will be in effect for Cameron Parish and
Jefferson County with tides around 2 feet above astronomical
predicted levels, with actual tide heights at high tide time
between 2.0 and 3.0 feet MWWH, and these numbers indicate
inundation levels right at the coast.

A Coastal Flood Advisory will be in effect for Vermilion, Iberia,
and St. Mary Parishes with tides between 1 and 2 feet above
astronomical predicted levels, with actual tide heights at high
tide time between 1.5 and 2.0 feet MWWH, and these numbers
indicate inundation levels right at the coast.

A Coastal Flood Advisory will be in effect for southern Calcasieu
Parish and southern Orange County around Sabine and Calcasieu Lake
with tides around 1 foot above astronomical predicted levels,
with actual tide heights at high tide time between 1.0 and 1.5
feet MWWH, and these numbers indicate inundation levels right at
the coast.

A Small Craft Advisory will be in effect for the coastal waters
for easterly winds 20 to 30 knots with gusts to near 40 knots and
seas from 7 to 14 feet.

If PTC 1 becomes more compact and stronger near the center then
we may see less impacts for the forecast area.

Rua

&&

.SHORT TERM...
(Tonight through Wednesday night)
Issued at 426 PM CDT Mon Jun 17 2024

Initial moisture plume will move across for the remainder of the
afternoon into this evening, and this will allow for widespread
showers and a few thunderstorms that will produce brief tropical
downpours and wind gusts around 35 mph. This activity will begin
to decrease after sunset with the loss of daytime heating.

On Tuesday, best deep tropical moisture plume around the large
circulation of PTC 1 will move into lower southeast Texas and this
area will have the higher rain chances along with higher rainfall
rates. PWAT values will be in the 2.25 to 2.5 inch range along
with MRH over 90 percent, so definitely tropical downpours.

With the long fetch and duration of the easterly winds, Ekman
spiral affect will help pile water on the coast allowing for high
tides that may bring some flooding during high tide times late at
night into the morning hours. Also, with water piling along the
coast, this will probably hinder proper drainage from main
riverstems that combined with the heavy rainfall will also
increase the flash flood threat.

On Wednesday, as the system moves further west, the heavy rain
threat will also move further to the west. Should be enough
moisture hanging around along with a weakness aloft to keep a good
chance of showers and thunderstorms in the forecast.

Rua

&&

.LONG TERM...
(Thursday through next Sunday)
Issued at 346 PM CDT Mon Jun 17 2024

At the start of the longterm period, high pressure is moving in
aloft and surface ridge starts building over the sern US from the
ern seaboard. A final hurrah of elevated PoPs are expected for at
least some of the area on Thursday with tropical disturbance
spinning out in sern Texas. Moisture plume still situated in south
Louisiana consisting of PWATs in the 1.70 to 1.90 inches will
support scattered to numerous showers and thunderstorms for the
daytime hours.

This time yesterday, guidance brought a weak erly trof across the
northern Gulf causing an increase in rain chances over the next
weekend. Now, guidance has a stronger sfc ridge building in from the
east into Friday, causing a downward trend in diurnally driven PoPs
into Saturday. The brief period of lower PoPs makes some sense
considering the relatively drier airmass moving in with the ridge.
There remains the chance of a weak erly trof or low pressure center
moving near Florida late in the weekend which would degrade the sfc
high and allow PoPs to flood back in late Sunday and Monday.
Forecaster confidence in this solution is low to medium and thus
broad changes to this extent of the forecast are very possible. For
now, the NBM`s PoPs for the weekend into Monday appear to capture
the latest forecast trend well enough and were left as is.

Temperatures rise steadily from Thursday to the weekend with highs
in the low to mid 90s.

11/Calhoun

&&

.AVIATION...
(06Z TAFS)
Issued at 1153 PM CDT Mon Jun 17 2024

Other than pushing back the timing of potential lower ceilings per
forecast soundings/time-height sections, no big changes to
previous TAF thinking...

Local 88Ds show waning convection across the forecast area...
maintained VCTS mentions in the short term for the wrn terminals
to account, but not really expecting much in the way of impacts
next hour or so. Conflicting signals in the guidance about the
arrival time of MVFR ceilings tonight...have elected to carry them
beginning overnight, but confidence is low. Next round of precip
should enter the area by late morning, with coverage spreading
inland/intensifying through the afternoon.

25

&&

.MARINE...
Issued at 426 PM CDT Mon Jun 17 2024

Potential Tropical Cyclone 1 is expected to move across the
southern Gulf of Mexico into eastern Mexico by Wednesday night.
The system is expected to have a rather large wind field along
with a tight gradient across the northwest Gulf of Mexico will
provide moderate to strong and gusty east to southeast winds in
the 20 to 30 knot sustained range with gusts up to 40 knots. This
will also allow for wave heights to increase in the 7 to 14 foot
range. A Small Craft Advisory will be in effect through mid week.

As long as the system stays weak, deep moisture will be out from
the north side of the system, keeping widespread showers and
storms through mid week.

Rua

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  72  85  71  90 /  30  50  20  30
LCH  74  85  75  89 /  50  80  50  70
LFT  76  86  76  91 /  50  70  30  60
BPT  76  86  75  88 /  40  80  70  70

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...Coastal Flood Warning until 7 PM CDT Wednesday for LAZ073-074.

     Coastal Flood Advisory until 7 PM CDT Wednesday for LAZ241-
     252>254.

TX...Coastal Flood Warning until 7 PM CDT Wednesday for TXZ615.

     Coastal Flood Advisory until 7 PM CDT Wednesday for TXZ616.

     Flood Watch from 7 AM CDT Tuesday through Wednesday evening for
     TXZ201-515-516-615-616.

GM...Small Craft Advisory until 7 AM CDT Thursday for GMZ450-452-455-
     470-472-475.

&&

$$

SHORT TERM...07
LONG TERM....11
AVIATION...25