913
FXUS64 KLCH 151209
AFDLCH

Area Forecast Discussion
National Weather Service Lake Charles LA
709 AM CDT Mon Jul 15 2024

...New AVIATION...

.SHORT TERM...
(Today through Wednesday night)
Issued at 317 AM CDT Mon Jul 15 2024

Locally, broad high pressure remains over the southern CONUS with
modest ridging extending over the western Atlantic to the FL
Peninsula. Seasonably warm temperatures will continue over the next
few days to complete the short term while under a light variable
southerly flow. Further to this, the present regime will allow the
marine boundary layer to extend over the I-10 corridor, while more
interior counties and parishes remain roughly 3-6F warmer trending
north into central LA and Eastern Tx. SFC high pressure ridging is
forecast to become slack by ahead of an upstream trough deepening
eastward across the Southern Plains.

The start of the work week will remain generally on the lower end
for POPS with drier air being entrained into portions of the lower
troposphere from central Tx. Therefore, most favorable region for
isolated showers and storms will remain toward the lower Acadiana
region with slight chances to carry west along the I-10 corridor
into eastern Tx with mainly Seabreeze driven convection during the
mid-late afternoon hours. Apart from any isolated storms, highs will
still reach across the spectrum of 90s from the coast to the
central portions of LA. While diurnal maximums of dewpoints keep us
out of advisory criteria, it should be noted both Monday and Tuesday
will still have several locations approach or briefly breach Heat
Indices of a 100F.

By Wednesday an upper level low stalled over central Tx will
consolidate and strengthen. Thus, throughout the day upper level
divergence will begin to increase with some signals of weak
perturbations aloft. Some guidance is a little more egregious to
bring the deeper 1000-500mb layer of elevated RH into south portion
of SETX and SWLA by midday, however, much of the more favorable
instability continues to trend above 3km AGL, meaning that activity
may be capped for most locations. However, by the evening hours, the
aforementioned upper level low and developing surface trough to the
further north begin to exhibit more baroclinic components over the
area creating the potential for scattered activity over a greater
area of coverage to occur during the evening and overnight hours
into Thursday.

Kowalski / 30

&&

.LONG TERM...
(Thursday through Monday)
Issued at 317 AM CDT Mon Jul 15 2024

A weakness aloft will be in place over the region as we begin the
long term period. An upper level trough rounding the upper level
ridge over the Mountain West will help push a surface front into the
forecast area on Thursday, with the front stalling out along the I-
10 corridor on Friday, with the frontal boundary waffling around the
forecast area through the weekend.

A very moist and unstable air mass will be in place ahead of the
frontal system and therefore, widespread shower and thunderstorm
activity is expected for the end of the week into the weekend.

PWAT values on Thursday are progged to be between 2.0 and 2.25
inches, with Mean Relative Humidity values over 70 percent, with
PWAT values over 2.25 inches and Mean Relative Humidity values over
80 percent for Friday. The PWAT values are near or above the 90th
percentile of SPC daily climo for Thursday and Friday. Relatively
light mid level winds will bring about slow storm motions with the
probability for mesoscale boundary collisions and cell mergers.
Therefore, some locally heavy rainfall will be possible and WPC has
outlined the northern portion of the forecast area on Thursday, and
the entire forecast area on Friday, with a Marginal Risk (level 1
out of 4) for Excessive Rainfall that may lead to flash flooding.

PWAT values lower some over the weekend, and closer to 2 inches
which is at the 75th percentile of SPC climo.

With the expected cloud cover and widespread convection, to go along
with some lower dew points, daytime heat temperatures will be a
little below climo norms, with max heat index readings kept in check
around 100 degrees or lower for Friday into the weekend.

07/Rua

&&

.AVIATION...
(12Z TAFS)
Issued at 700 AM CDT Mon Jul 15 2024

VFR conditions to persist for majority of the day with the
exception of isolated locations, particularly along Eastern sites
LFT and ARA where popup TS are possible. Most favorable time for
convection along this region as well as locations further west
into SETX will be during the mid-late afternoon where Seabreeze
may help outflow boundaries to develop the isolated convection.
Otherwise sfc winds to back and retain more southerly components
through the evening hours before becoming more variable through
remainder of the overnight hours.

30

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  96  73  97  74 /  20  10  10   0
LCH  93  78  92  78 /  30  10  30  10
LFT  94  78  94  79 /  40  10  50  10
BPT  92  76  93  77 /  20  10  20  10

&&

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

$$

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