551
FXUS64 KLCH 160846
AFDLCH

Area Forecast Discussion
National Weather Service Lake Charles LA
346 AM CDT Tue Jul 16 2024

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

.SHORT TERM...
(Today through Thursday night)
Issued at 322 AM CDT Tue Jul 16 2024

Todays weather will continue with the broadening regime of high
pressure across SETX / SWLA and the central Gulf. Meanwhile an upper
level low pressure trough gradually shifts toward SETX and begins to
deepen into Wednesday morning. Seasonably warm temperatures are
expected to persist today and tomorrow with southerly onshore flow.
Continued dry air from the west in the lower troposphere will
continue to become entrained throughout the mid-upper levels of the
atmosphere. Despite, the moderate dry layers, much of the column for
locations closer to the coast will still remain very moist, yielding
PWATs 1.5-2.0 inches throughout the day Tuesday. Thus similar to the
previous day, any isolated convection that takes place could allow
for a few efficient rain producers. The most favorable signals for
POPS remain over the Acadiana / Atchafalaya basin whereas drier
conditions are favored in SETX. By Wednesday, the upper level trough
begins to fill and broaden at an attempt to phase with the southern
tier of the northern Jet. Such a pattern allows for many
perturbations along with weak speed divergence yielding slightly
better chances for isolated to scattered POPS across area while
still favoring SE portions of LA. Southerly flow and highs grappling
on to the low  mid 90s will be trending north into interior
portions of the CWA.

By the early evening hours trending into Thursday, a frontal
boundary stretching across the Ozarks will shift further toward
ARKLATEX region later that morning. Along and ahead of this boundary
stronger forcing dynamics are forecast to develop over SETX and SWLA
to initiate scattered to widespread showers / storms over the area.
Therefore, temperatures will be lowered compared to the previous
week by a few degrees with increased cloud coverage. As is the case
with many summertime convective weather, some cells may acquire a
few stronger characteristics. That said, forecast soundings do not
suggest notable severe characteristics at this time. Thus, some
gusty outflows and some heavy rainfall would be the main focus- for
any well-developed storms that occur. Frontal boundary is expected
to shift toward the Gulf Coast during the evening hours Thursday
leading into early Friday morning. During this period POPS continue
to increase as the front starts to slow forward progression toward
the offshore waters.


Kowalski / 30


&&

.LONG TERM...
(Friday through Tuesday)
Issued at 322 AM CDT Tue Jul 16 2024

A short wave moving around a strong upper level ridge over the
Mountain West will help push a surface front into the forecast area
as the long term begins on Friday, with this frontal system stalling
along the I-10 corridor on Saturday before washing out over the
remainder of the weekend.

A very moist and unstable air mass will be in place as the front
system arrives. With a weakness aloft and surface frontal
convergence to work with the moisture, widespread shower and
thunderstorm activity is expected to develop and continue into the
weekend. Even after the surface front washes out, plenty of moisture
will still be in place, to go along with the weakness, aloft to
allow for any daytime heating to initiate widespread shower and
thunderstorm activity.

PWAT values on Friday are progged to be between 2.0 and 2.25 inches,
with Mean Relative Humidity values over 75 percent. The 90th
percentile for PWAT from SPC climo is 2.15 inches for this time of
year, so PWAT will be near or above this level. Warm cloud layer is
progged to be in the 12k to 14k foot range, to along with the high
mean layer relative humidity values and the anomalously high
precipitable water that torrential downpours with high rain rates
will be possible with the stronger convection. Add in relatively
light mid level winds to bring about slow storm motions with the
probability for mesoscale boundary collisions and cell mergers.
Therefore, some locally heavy rainfall will be possible on Friday
and WPC has outlined the entire forecast area with a Marginal Risk
(level 1 out of 4) for Excessive Rainfall that may lead to flash
flooding that lingers for locations south of the frontal boundary on
Saturday.

With the expected cloud cover and widespread convection, the heat is
expected to be kept in check somewhat with max heat index readings
mainly at or below 100 degrees for Friday into the weekend.

07/Rua

&&

.AVIATION...
(06Z TAFS)
Issued at 322 AM CDT Tue Jul 16 2024

Conditions to trend mainly VFR through the midday after some
patchy BR mixes out during the early morning hours. Areas of VCTS
best favored toward the I-1O corridor and further along the lower
Acadiana region. A likely timing for convection to take place
lends during the mid to late afternoon where Seabreeze boundaries
may help initiate the isolated activity. Winds will be due
southerly about 5-10kts with again mainly VFR conditions
prevailing into the evening.


&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  96  74  96  74 /  10  10  30  10
LCH  92  78  92  78 /  20  10  50  20
LFT  92  78  94  78 /  30  10  60  20
BPT  92  77  92  76 /  10  10  40  20

&&

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

$$

SHORT TERM...30
LONG TERM....07
AVIATION...87