Severe Thunderstorm Warning 40, NWS Lake Charles, LA

Area Forecast Discussion
National Weather Service Lake Charles LA
331 PM CST Mon Mar 4 2024

...New SHORT TERM, LONG TERM, MARINE...

.SHORT TERM...
(Tonight through Wednesday night)
Issued at 325 PM CST Mon Mar 4 2024

Surface analysis shows broad low pressure and a cold front over
the Central Plains, while high pressure is near the Carolinas and
a weak surface trough is situated overhead. Aloft, zonal flow is
ongoing overhead with an approaching shortwave just to our west
at this time. Area radar shows quite a bit of activity ongoing
along and east of the I-49 corridor, which is subsequently along
and east of the approx location of the surface trough. Surface obs
show temps ranging from the mid to upper 70s, except for near AEX
where thicker cloud cover has kept temps in the upper 60s to low
70s, while skies are mostly cloudy and winds are out of the south
areawide.

As we head into tonight, convection should continue mainly along
and east of I-49, while the remainder of the CWA will see an
occasional shower or two. Activity should begin to taper down a
bit as we head towards midnight, with a lull in convection
expected area-wide overnight. That's not to say we won't see an
occasional shower or two but widespread activity looks fairly
unlikely. However, we will more than likely see another round of
marine fog pushing inland overnight, which will mainly become an
issue for those of us near and south of I-10. Otherwise, warm and
muggy overnight conditions are once again expected with lows only
falling into the low to mid 60s.

Moving into tomorrow, a second round of convection is expected to
begin near sunrise as the aforementioned upper level shortwave
traverses the region and provides additional support for
convection. The CAMs are not in good agreement with the evolution
of tomorrow's convection, with solutions ranging from a quick
moving MCS feature to more scattered/widespread activity similar
to today. Once again, SPC has the entire CWA outlined within a
Marginal Risk (level 1 out of 5) for severe weather tomorrow, with
the main threats being wind and hail. As convection should begin
to taper off through the mid day, the severe threat will come to
an end, with a dry afternoon expected. Cloud cover may clear out a
bit through the afternoon as well, opening the door for warmer
temps with highs expected to top out in the upper 70s to low 80s.

Wednesday will be our only true quite day this week, with a lull
in convection expected between tomorrow's departing shortwave and
the next shortwave that is scheduled to arrive on Thursday.
Wednesday will bring partly sunny skies and highs in the lower
80s, while overnight lows will fall into the upper 50s to low 60s.

17

&&

.LONG TERM...
(Thursday through next Sunday)
Issued at 325 PM CST Mon Mar 4 2024

The first half of the long term will be stormy while the second half
will be smooth sailing. Flow aloft will start off zonal, while at
the surface the CWA will be at the base of a ridge extending from
the Great Lakes down to the Gulf. Winds will be out of the south
with some decent moisture advecting into the region. Thursday
morning, a closed off upper level low will be off the coast of
SoCal. Over the day, this system will move over the desert SW then
make its way into the Southern Plains on Friday. At that time, a
rich plume of moisture will move in as a low level trough moves in
and across the Gulf Coast on Friday morning. PWATs will shoot up
from around an inch to the 1.6-1.8 inch range which is well over the
90th percentile.

We will see some isolated showers and storms ramp up midday
Thursday, however the bulk of the activity will hold off until later
that evening ahead of the front. Currently there is a Marginal Risk
for excessive rainfall and a 15% risk area for severe storms over
the northern tier of our CWA on day 4 (Thursday) to account for the
showers and storms expected that night. Then the Marginal Risk ERO
expands to cover the entire area while the 15% risk area expands to
cover along and north of the I-10 corridor on day 5 (Friday).

The models timing of frontal passage is a bit off, however we could
see precip clear the area by as early as Friday night. Cooler and
drier air will move in quickly behind the front with temperatures
falling around 10 degrees. Post frontal MaxTs will struggle to get
into the 70s while MinTs will fall into the 40s to 50s.

Stigger/87

&&

.AVIATION...
(18Z TAFS)
Issued at 1137 AM CST Mon Mar 4 2024

A messy pattern will persist through the TAF period with
improvements expected later tomorrow. A combination of MVFR, IFR,
and LIFR ceilings, reduced VIS, showers and thunderstorms, and
fog are expected at all terminals through the period. Short range
guidance is becoming more in agreement with the first ongoing
round of convection tapering off later this evening, with a quiet
period (precip wise) overnight, and a secondary round of
convection tomorrow morning. Although overnight should be mainly
free of convection patchy dense fog, low ceilings, and reduced VIS
will continue. Conditions today and tomorrow will be worse near
and within convection, while away from convection low ceilings
will likely be the main concern.

17

&&

.MARINE...
Issued at 325 PM CST Mon Mar 4 2024

Onshore flow will continue through the end of the work week.
Tonight, fog will build in quickly once again across all zones
post-sunset, and another Dense Fog Advisory has been issued through
10AM tomorrow. Otherwise, an approaching upper level disturbance will
bring a few scattered showers and thunderstorms overnight, with
coverage potentially increasing a bit as we head towards sunrise
tomorrow. After the disturbance exits east of the region, no
precipitation is expected tomorrow evening through early Thursday.

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  62  79  59  81 /  60  40   0   0
LCH  64  80  61  80 /  50  40   0   0
LFT  66  79  62  80 /  70  50   0   0
BPT  64  84  62  81 /  40  30   0   0

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...None.
TX...None.
GM...Dense Fog Advisory until 10 AM CST Tuesday for GMZ430-432-435-
     436-450-452-455.

     Dense Fog Advisory from 9 PM this evening to 10 AM CST Tuesday
     for GMZ470-472-475.

&&

SHORT TERM...17
LONG TERM....87
AVIATION...17