Severe Thunderstorm Warning 21, NWS Lake Charles, LA

Area Forecast Discussion
National Weather Service Lake Charles LA
403 PM CDT Fri May 13 2022

.SHORT TERM [Tonight through Sunday]...

Scattered convection has blossomed along the Atchafalaya Basin in
a region of enhanced MSTR convergence and divergence aloft between
an eroding mid/upper ridge over TX and an upper trof over the SE
CONUS. This activity is in an environment characterized by weak
wind shear but more than adequate buoyancy, so the severe weather
risk is limited, but not zero. Pulse-type events appear most
likely as cells move/propagate slowly southward, posing
a risk of downburst winds and perhaps borderline severe hail along
with locally heavy rainfall, though clusters progressing more
quickly along outflows are also possible. Driven largely by
diurnal instability, this activity may linger into early evening
prior to dissipating. Once the convection dies off, a quiet night
is expected with some patchy fog possible overnight into early SAT
morning.

Convective evolution SAT is a bit nebulous and will likely depend
at least in part on residual outflows left over from today. CAM
guidance varies quite a bit, but generally depict the same overall
idea of scattered convection and/or TSTM clusters initiating in
the afternoon and subsequently tracking southward across mainly
east and south central LA, though a few are as far west as the
Sabine River. With perhaps a little more areal involvement to the
clouds/convection, highs may not be quite as warm as today, but
upper 80s to lower 90s are still expected.

The mid/upper level ridge out west will flex a bit eastward on
SUN, which will knock PoPs back down to just a small chance across
the lower Atchafalaya. Assuming any decline tomorrow, highs will
certainly rebound on SUN, with lower to mid 90s expected. As for
low temperatures, little day to day variation is expected, with
readings in the upper 60s to around 70.

13

.LONG TERM [Monday through Friday]...

The long term period will be characterized by several more days of
hot and dry weather, with a repetitive forecast of above average
temperatures and no rainfall expected. At the surface, weak high
pressure will meander over the NWern Gulf at the start of the week,
slowly shifting eastward through the second half of the week as low
pressure amplifies across the Plains. Aloft, ridging will be
situated over the Rockies and Texas, while a shortwave trof will be
located over the eastern Gulf to start the week. With the forecast
area located between these two features, a fairly dry NWerly flow
aloft will be overhead to start the week, helping to suppress any
rain chances.

Moving into the Tue-Wed time frame, shortwave troffing begins to
side east and become absorbed by a larger trof over New England,
while ridging slides eastward as well and begins to flatten
overhead. The broad flat ridge will then remain overhead through the
end of the week resulting in, you guessed it, more dry and hot
weather. With more of a zonal flow aloft, moisture begins to return
to the mid levels, allowing for a bit more cloud cover and some
increase in humidity through the second half of the week, especially
by Friday. However, lack of any good forcing mechanisms both at the
surface and aloft will keep rain at bay. With ridging overhead, no
rain, and plenty of sunshine, temperatures continue to warm up well
above seasonal norms, with highs topping out in the low to mid 90s
each day next week.

17

&&

.MARINE...

Onshore flow will persist through the weekend with isolated to
scattered showers and thunderstorms possible across the coastal
waters east of Intracoastal City during the afternoon and evening
hours today through Sunday.

13

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  69  90  68  92 /  20  30  10   0
LCH  68  89  69  91 /  10  10  10  10
LFT  70  89  69  90 /  50  30  10  20
BPT  68  90  69  92 /   0  10   0   0

&&

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

&&