499
FXUS64 KLCH 030930
AFDLCH

Area Forecast Discussion
National Weather Service Lake Charles LA
430 AM CDT Mon Jun 3 2024

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

.UPDATE...
Issued at 1014 PM CDT Sun Jun 2 2024

Evening update primarily involved updating PoPs in association
with convection moving into central and west Louisiana. Also added
in areas of patchy fog where we`ve had excessive rainfall today.

Convection is beginning to look less and less robust the further
east it moves. This is a sign of waning CAPE and developing CIN.
While there remains enough MLCAPE to keep storms going, perhaps
their severity will diminish below traditional severe limits. That
being said, some storms with wind gusts 40 to 50 mph could clip
into Rapides and Avoyelles parishes in the next hour or two.
Previous storm systems have proven that it doesn`t take 60+ mph
winds to cause damage or power outages, so that possibility
remains until these areas can clear from storm potential.

11/Calhoun

&&

.SHORT TERM...
(Today through Wednesday night)
Issued at 417 AM CDT Mon Jun 3 2024

Unsettled is the key message of the forecast package this morning
with POPs continuing to become more prevalent in our very
subtropical moist environment. The recent trend with this pattern
has been remnant boundaries from storm complexes across central TX
and LA modifying over SETX and SWLA and utilizing relatively large
instability and high PWAT values to facilitate redevelopment across
the CWA daily. Short range guidance has been fickle in being able to
target genesis and evolution of scattered to widespread
showers/storms. Basis the latest guidance now, this trend of
relatively unorganized storm complexes will continue into the early
work week. What hasn`t changed, are the signals for light ridging
from the western Atlantic to build further into the central GOM
briefly by mid week. However, given a consistent southerly flow and
active pattern across the midwest, the potential for storm complexes
to redevelopment even during the mid week is non-zero.

Any patchy fog that has developed overnight will quickly mix out to
hazy, mostly cloudy skies with highs building into the upper 80`s
for most inland locations. Upper level shortwave trough over the
central plains will pivot near the Ozarks before lifting across the
Ohio Valley into Tuesday. Currently, forecast remains that the
stronger dynamics which favor severe weather will be limited in this
region and remain further north closer to the more active region of
the upper level pattern. Signals have grown stronger for troughing
to develop closer into the ARKLATEX region ahead that pattern.
Therefore, similar to the past couple days, another round of
scattered storms have become more favorable to develop into the
afternoon. This thinking aligns closely with SPC guidance of a
marginal and slight risk encompassing the northern ~ 1/3rd of the
CWA combined with a marginal risk of excessive rainfall.

While much of the upper level shortwave continues to feed downstream
toward the TN Valley, small perturbations in the flow aloft yield a
weakly positive tilted shortwave across the region into Tuesday
evening over SETX / SWLA. Much of the global guidance and National
Blend of Models does not pick up well on the precipitation
potential, however, there are no significant limiting factors in the
forecast atmospheric profile that would confidently prevent
redevelopment of clustered storms trending SE from Central TX. That
said, considering the upper level dynamics, the most favorable
regions would lie east of SETX into Acadiana / Atchafalaya. Moving
forward into Wednesday, the ridge extension mentioned earlier
appears strongest throughout the day which indicate that enough
subsidence will be in place to limit any POPs. However, unlike a
large synoptic high pressure cell, this weak ridging will be short
lived before receding back east over the FL Peninsula.

 Kowalski/30

&&

.LONG TERM...
(Thursday through Monday)
Issued at 417 AM CDT Mon Jun 3 2024

Looking into the long range, confidence in the forecast pattern does
not get any stronger with a very active northern jet across S`rn
Canada and the Midwest while the subtropical jet across Mexico and
the Gulf becomes more chaotic, albeit with weaker Jet Maxes. A large
and deep surface low will stall out north the Great Lakes with
troughing deepening south into Ohio Valley region for the remainder
of the forecast outlook. Meanwhile the subtropical pattern also
shifts further south toward the northern Caribbean while en
elongated stationary boundary left over from the aforementioned
northern stream shortwave meanders toward the ARKLATEX region. There
has been a few run to run consistency in this boundary sinking south
across Central LA and E`rn Tx into Saturday which would serve as a
focal region for shower and thunderstorm development into the
upcoming weekend for the CWA.

 Kowalski/30

&&

.AVIATION...
(00Z TAFS)

Main area of strong to severe TSRA over Western Louisiana along
remnant outflow boundary far away from terminals, so will be
ending the VCTS at this time. Otherwise, MVFR ceilings expected
by 09z through 15z. Southeast winds 10-12 kts expected to remain
elevated around 5-7 kts later this evening and overnight,
increasing by 15z to 8-10 kts, and becoming south 12-16 kts with
gusts 20-24 kts by 18z Monday. Higher chances (30-40%) of TSRA
for eastern terminals Monday afternoon, with VCTS beginning
around 17-18Z with a PROB30 group from 19-24z for all sites.

&&

.MARINE...
Issued at 330 PM CDT Sun Jun 2 2024

Onshore flow is expected to begin gradually increasing tonight,
with caution conditions forecasted by Monday night as the gradient
tightens thanks to lower pressures over the srn Plains. These
elevated winds are progged to linger into mid-week before
settling.

25

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  89  73  91  74 /  50  20  20   0
LCH  87  76  89  78 /  30  10  10   0
LFT  89  78  91  78 /  30  10  20   0
BPT  89  77  90  78 /  40  10  10   0

&&

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

$$

SHORT TERM...30
LONG TERM....30
AVIATION...08