151
FXUS64 KLCH 251958
AFDLCH

Area Forecast Discussion
National Weather Service Lake Charles LA
258 PM CDT Sat May 25 2024

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

.SHORT TERM...
(Tonight through Monday night)
Issued at 255 PM CDT Sat May 25 2024

The Memorial Day holiday weekend is starting off with some
unseasonably hot and humid conditions. Just mainly scattered
diurnal clouds have formed this afternoon, however with a cap in
place, no significant shower activity is forming. With the lack of
clouds, and modest south winds pumping in low level Gulf moisture,
air temperatures are in the upper 80s to mid 90s, with dew points
still in the mid 70s, allowing the heat index reading at reliable
observation sites to range from near 100F to 107F.

A very similar pattern will hold into tomorrow with high pressure
ridging in from the east allowing southerly flow to bring in Gulf
moisture to allow for high dew points and humidity. Upper level
ridge will provide cap to keep away any shower and allow for
enough sunshine for temperatures again to be from near 90F to the
mid 90s, and with that heat index values from 100F to 107F which
are just below the local heat advisory criteria.

At night and early morning, light winds may allow the high
humidity to combine with particles from residual agricultural
smoke for some patchy fog/haze to form, however only light
visibility restrictions are expected.

Monday/Memorial Day, the forecast is a little more tricky. The
surface ridge will still provide winds off the Gulf for plenty of
humidity and high dew points. However, the upper level ridge
centered over Old Mexico, begins to retreat to the southwest some
and this will cause a flattening of the upper level ridge over the
forecast area. A short wave moving across during this time might
be able to push a weak surface boundary, or convective outflow
from convection to the north into the forecast area and clash
with the moist unstable environment to allow for a chance for
showers and thunderstorms.

With the uncertainty of the timing of any features and dropping
down from the northwest and how strong the surface boundary will
be will only keep a slight chance for showers or storms in the
afternoon into the night. SPC does have the area outlooked in a
Marginal Risk for severe storms during that time frame. However,
with such a small chance for storms, it may be one of those
situations with favorable CAPE, mid level shear, and mid level
lapse rate, that if an isolated storm develops it will produce
strong downburst winds and/or large hail.

What is becoming a little more certain is the heat for Memorial
Day. Using a combination of CONSMOS and 50th percentile of NBM,
afternoon temperatures will be in the mid 90s, combined with dew
points in the mid 70s, afternoon heat index values are looking
more likely in the 105F to 110F range. Therefore, the first Heat
Advisory of the 2024 summer season may have to be issued,
especially for portions of southeast Texas where the apparent
temperature tool is giving solid readings between 108F and 110F.

Rua

&&

.LONG TERM...
(Tuesday through next Friday)
Issued at 255 PM CDT Sat May 25 2024

On Tuesday, a weak frontal boundary will slowly push south across
the CWA through the day, allowing for winds to briefly become more
ENE to E. Aloft, Mid level troughing will be over the Great Lakes
while ridging remains to our south from Mexico to FL, resulting in a
mainly zonal flow overhead. Tuesday looks to be another hot and
humid day, with highs reaching into the low to mid 90s, while heat
indices will peak in the mid 90s to lower 100s. As the boundary sags
through the area on Tuesday, the first in a series of weak
disturbances passing overhead may be able to induce some isolated
afternoon convection.

Moving into the second half of the week the boundary moves offshore
and becomes increasingly washed out, as surface winds become
southeasterly again on Wednesday. A small shot of "cooler" air is
however, expected to arrive late Tuesday, and although it won`t
actually feel any cooler it should bring temps back to near seasonal
norms for the later half of the forecast period. Daytime highs
should generally range from the low 80s to near 90 from Wed through
Sat, while overnight lows are expected to fall into the upper 60s
inland to mid 70s at the coast.

In addition, at least small POPs return to the forecast each day
through the later part of the week, as moisture remains elevated
overhead and a couple more weak disturbances pass overhead aloft
helping to induce afternoon convection. Overall, doesn`t look like
any one day will bring better rain chances than the other, with POPs
generally around 20% or so each afternoon for the time being.

17

&&

.AVIATION...
(18Z TAFS)
Issued at 1228 PM CDT Sat May 25 2024

The remainder of the afternoon looks like VFR conditions as skies
should be scattered and any ceilings that may from will be at VFR
levels. Southerly winds will be a little breezy at times with
occasional gusts to near 20 knots.

Tonight, light south winds will prevail, with some low clouds
forming during the evening hours under the cap at MVFR levels
which will continue into the overnight. Particles from residual
agricultural smoke may combine with the high humidity to produce
brief light visibility restrictions from patchy fog/haze,
although conditions should remain at MVFR levels.

Rua

&&

.MARINE...
Issued at 255 PM CDT Sat May 25 2024

Surface high pressure located off to the east of the Florida coast will
continue to ridge into the coastal waters and dominate the low
levels for the period. This will allow for mainly southerly wind flow
to persist through the period.

Winds will increase some tonight into Sunday as low pressure
forms over the Plains with winds approaching 20 knots and thus
small craft exercise caution will be headlined during that period.

An upper level ridge is expected to hold over the northern Gulf of
Mexico and no shower or thunderstorm activity is expected through
the holiday weekend.

Rua

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  74  92  74  95 /   0   0  10  10
LCH  77  88  78  93 /   0   0   0  10
LFT  77  91  78  94 /   0   0   0  10
BPT  77  90  79  94 /   0   0   0  10

&&

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

$$

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