922
FXUS64 KLCH 262355
AFDLCH

Area Forecast Discussion
National Weather Service Lake Charles LA
655 PM CDT Sun May 26 2024

...New AVIATION, CLIMATE...

.SHORT TERM...
(Tonight through Tuesday night)
Issued at 323 PM CDT Sun May 26 2024

Another rather humid for May day across the forecast area with
heat index readings around 100F to 105F degrees. Southerly breezes
from the pressure gradient between a high near Florida and a low
over the Plains has helped keep air temperatures down a bit this
afternoon, and a cap in place has helped preclude any significant
convection. Will have to watch for any convection that develops
later tonight near a surface boundary along the Red River valley
as the outflow from this may try to get a few showers going in
central Louisiana just before daybreak.

Pattern change will begin on tomorrow Memorial Day. The center of
the upper level ridge over old Mexico will shift back to the
southwest helping to flatten the ridge over the forecast area.
This will allow a series of short waves to carve out a trough from
the Great Lakes down to the Gulf coast that will help allow
northwest flow to develop aloft.

The first notice of this pattern change will be a surface boundary
will move into the forecast area on Monday afternoon. Before the
boundary arrives, lighter south winds and some compression warming
ahead of the boundary will allow air temperatures to soar into the
mid and possibly upper 90s. Meanwhile, plenty of low level Gulf
moisture will be in place with afternoon dew points in the mid
70s. The combination of the 2 will mean max heat index readings or
the apparent temperature will soar to near danger levels between
108F and 111F degrees. Therefore, a Heat Advisory will be in
effect for the area, with the exception of right along the coast,
from Noon to 8 pm CDT.

Also, the boundary may combine with the daytime heating to break
the cap and kick off thunderstorms. At this point, storm activity
is expected to be isolated in nature starting late in the
afternoon (like after 3 pm,) then decreasing in the evening with
the loss of daytime heating. Despite the activity to remain
isolated in nature, strong CAPE values of over 4000 j/kg, 0-6km
shear between 40 and 50 knots, favorable mid level lapse rates,
and downdraft DAPE (DCAPE) over 1500 j/kg, will bring about a
conditional potential of severe storms, with damaging microburst
winds the main concern. Due to the factor storms are expected to
be limited in nature, a Marginal Risk Potential (level 1 out of 5)
will be outlined for the forecast area.

The surface boundary will stall over the forecast area on Tuesday,
daytime heating and Gulf moisture will combine for a chance of
showers or storms. With the northwest flow aloft, will have to
watch to see if any short wave energy can make its way into the
forecast area and help enhance any storm activity.

Dew point will be a little lower on Tuesday, along with a better
chance to see clouds and convection keeping air temperature down
just a bit, and thus keeping heat index in check that a heat
advisory is not anticipated on Tuesday.

Rua

&&

.LONG TERM...
(Wednesday through next Saturday)
Issued at 323 PM CDT Sun May 26 2024

A weak frontal boundary will be located off the coast early
Wednesday, while aloft the forecast area will be situated beneath a
persistent W to NW flow between troughing to the north and ridging
to the south and west. This same general mid/upper level pattern
will persist into the weekend, while the surface boundary will
gradually lift back inland as a warm front through the later half of
the work week. At the same time, a series of weak disturbances will
pass overhead in the W/NW flow aloft. The first of these
disturbances will arrive Wednesday, inducing scattered showers and
thunderstorms by the afternoon hours. Rain chances for Wed are much
better today vs. yesterday, with 30-50% POPs now on tap.

Thursday through Sunday will bring a fairly repetitive pattern as a
few more disturbances slide overhead though the period. Rain chances
look to increase each day through the late morning into the
afternoon, before tapering off by the evening hours, as a
combination of daytime heating and the upper disturbances induce
daily showers and thunderstorms. Temperature wise, the entire period
will consist of highs in the upper 80s to low 90s, with overnight
lows in the upper 60s to mid 70s, which is slightly below seasonal
norms.

17

&&

.AVIATION...
(00Z TAFS)
Issued at 655 PM CDT Sun May 26 2024

Pretty much a persistence forecast aviation-wise with MVFR
ceilings expected to develop this evening with good low-level
moisture lingering on persistent srly flow. Restrictions to
visibility are not expected to be much of a problem except at KLCH
where vis is already down to 4SM in haze and will likely stay
there through tonight. As usual, conditions will improve post-
sunrise with VFR conditions expected by late morning. With a
lesser gradient in place, elevated srly winds like today are not
expected on Monday. While there is a slim chance at convection by
Monday afternoon, coverage looks minimal to leave out any mentions
at this time.

25

&&

.MARINE...
Issued at 323 PM CDT Sun May 26 2024

Modest southerly flow over the coastal waters this afternoon with
the pressure gradient between a surface high near Florida and a
surface low over the Plains. The low will move further away from
the forecast area tonight, and this will help reduce the pressure
gradient and lower wind speeds.

For Memorial Day through the middle part of the week, the surface
high near Florida will weaken some, however still ridge westward
into the coastal waters. There, mainly light southerly flow and
low seas can be expected.

Any shower or thunderstorm activity is expected to stay north of
the coastal waters during the period.

Rua

&&

.CLIMATE...
Issued at 655 PM CDT Sun May 26 2024

All five primary climate sites set/tied record warm low
temperature records for 5/26 (assuming nothing odd like an
unexpected rapid cooling happens).

LCH today`s low: 79 (previous record: 78/2000 & earlier)
BPT today`s low: 79 (record: 79/2000)
LFT today`s low: 79 (previous record: 77/1909)
AEX today`s low: 76 (record: 76/2000)
ARA today`s low: 78 (previous record: 77/1989)

25

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  74  95  70  93 /  20  10  10  20
LCH  78  92  75  92 /  10  20  20  20
LFT  79  94  76  94 /  10  20  20  20
BPT  78  94  75  92 /   0  20  20  20

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...Heat Advisory from noon to 8 PM CDT Monday for LAZ027>033-044-
     045-141>143-152-153-241>243.

TX...Heat Advisory from noon to 8 PM CDT Monday for TXZ180-201-
     259>262-515-516-615-616.

GM...None.
&&

$$

SHORT TERM...07
LONG TERM....17
AVIATION...25