Severe Thunderstorm Warning 247, NWS Lake Charles, LA

Area Forecast Discussion
National Weather Service Lake Charles LA
540 AM CST Tue Nov 5 2024

...New AVIATION...

.SHORT TERM...
(Today through Thursday night)
Issued at 300 AM CST Tue Nov 5 2024

Tuesday morning surface analysis shows high pressure ridging into
the area from the NE, while a cold front is draped from NErn
Missouri across the Ark-La-Tex region. Regional radar shows a
line of showers and thunderstorms ongoing ahead of this boundary
across central/east TX, while closer to home light shower activity
is streaming north out of the Gulf.

Now through roughly 18Z, the cold front will continue to march
towards, and into, the forecast area. An upper level shortwave
driving the front eastward will eventually eject NEwrd later this
morning, before becoming absorbed in the larger scale trough over
the Midwest. This will cause the front to slow down and stall
through the later half of the day, as upper level support wanes.
In addition, the shortwave ejecting NE will reduce support for
showers and storms along the front. Therefore, this morning will
bring our best chances of rain as the boundary moves into the area,
particularly across SE TX, before convection becomes much less
organized by the afternoon hours. SPC has outlined a Marginal Risk
(level 1 of 5) for severe weather across all our SE TX counties as
well as most of our LA parishes, excluding lower Acadiana. The
risk for severe storms will be best through the morning, with the
greatest risk being damaging winds. In addition, WPC has outlined
nearly the same region in a Marginal Risk (level 1 of 4) for
Excessive Rainfall today, with rainfall amounts also expected to
be highest through the morning hours.

This afternoon into tonight as upper level support diminishes and
the front stalls overhead convection will become isolated to
scattered in nature. West of the front, slightly cooler temps are
likely overnight and tomorrow, with overnight lows in the low to
mid 60s and daytime highs in the upper 70s to low 80s expected.
East of the front, onshore flow will keep warm and humid
conditions in place, with overnight lows in the low to mid 70s and
daytime highs in the mid to upper 80s.

The stalled boundary will gradually transition to a warm front
overhead tomorrow, before sliding back west tomorrow evening
through early Thursday. This will bring warm and humid conditions
back area-wide, with highs on Thurs in the low to mid 80s. In
addition, as the boundary retreats it will bring an end to any
lingering shower activity, with only minimal rain chances expected
across SE TX on Thurs and dry conditions elsewhere.

17

&&

.LONG TERM...
(Friday through Tuesday)
Issued at 300 AM CST Tue Nov 5 2024

Unfortunately, the long term forecast is of low confidence as a
number of different scenarios showing up on the deterministic and
ensemble guidance. The main players are a strong upper level low and
trough moving east over the southwestern states and Tropical Cyclone
Rafael in the Gulf of Mexico.

By the start of the long term, Rafael is expected to be a Hurricane
over the east-central Gulf of Mexico. According to the official
track from NHC, Rafael will be slowing and moving west-northwest
across the central Gulf of Mexico. Ultimately the movement and
strength of the upper level trough will likely affect Rafael, as a
stronger, deeper, and faster moving trough will produce strong
southwest shear, along with drier air over the northern Gulf of
Mexico, this will tend to weaken Rafael if it heads toward the
northern Gulf of Mexico over the weekend.

An unseasonably warm and humid air mass will likely be over the
forecast area on Friday. Question will be over the weekend if the
upper level trough can push a Pacific type cold front into or
through the forecast area. Of the global models, GFS brings the
front through on Saturday, while the ECMWF holds the front back to
the west. Due to this, there is a large spread in temperatures and
rain chances. This is especially seen in the overnight lows with
around a 20F plus degree difference between the 75th and 25th
percentile of the whisker plot for overnight lows starting Saturday
night. Until better agreement can come about, will go with the NBM
deterministic values that are just a tad below the mean of the plot.

07/Rua

&&

.AVIATION...
(12Z TAFS)
Issued at 532 AM CST Tue Nov 5 2024

A messy weather pattern will unfold through the forecast period as
a front moves into the area and eventually stalls overhead. Now
through the midday, ceilings will waffle between MVFR and VFR,
while scattered convection will continue to stream north across
the region while simultaneously increasing in coverage from the
west. Most of this convection should be light to moderate shower
activity, with a few embedded thunderstorms possible. In addition,
some gusty winds will continue to be possible this morning. This
afternoon, ceilings largely become VFR overhead while convection
thins out a bit in coverage and winds relax. Still could see a
heavy downpour or two through the afternoon but overall coverage
should be less. Tonight, isolated to scattered showers continue to
stream across the region. In addition, patchy fog will become
possible post midnight, while ceilings will gradually fall from
VFR to IFR and LIFR.

17

&&

.MARINE...
Issued at 300 AM CST Tue Nov 5 2024

Elevated southerly winds will gradually diminish today as a cold
front moves into the region and allows the pressure gradient to
relax. Small Craft Advisories continue across all Gulf zones this
morning, and will gradually drop off by noon as a result. Tonight
through the later half of the week, light to moderate winds
continue. Tropical Storm Rafael across the Western Caribbean Sea
is expected to move northwest and enter the Southeast Gulf of
Mexico later this week through the weekend, which will likely
bring some increased seas and possibly gusty winds to the Gulf
zones later in the period.

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  83  64  78  64 /  70  70  50  20
LCH  84  68  82  69 /  50  40  20  10
LFT  85  72  85  70 /  40  30  20  10
BPT  84  67  83  70 /  60  40  20  10

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...Coastal Flood Warning until 6 AM CST early this morning for
     LAZ073.

     Coastal Flood Advisory until 6 AM CST early this morning for
     LAZ074-241-252>254.

TX...Coastal Flood Warning until 6 AM CST early this morning for
     TXZ615.

     Coastal Flood Advisory until 6 AM CST early this morning for
     TXZ616.

GM...Small Craft Advisory until 6 AM CST early this morning for
     GMZ430-432-435-436.

     Small Craft Advisory until 10 AM CST this morning for GMZ450-452-
     455.

     Small Craft Advisory until noon CST today for GMZ470-472-475.

&&

SHORT TERM...17
LONG TERM....07
AVIATION...17