296
FXUS64 KLIX 181725
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
1225 PM CDT Wed Sep 18 2024

...New AVIATION...

.UPDATE...
Issued at 1005 AM CDT Wed Sep 18 2024

Forecast looks to be on track for this afternoon. Did make some
minor adjustments to PoPs, blending the HRRR and NBM, to show
chances for showers are looking more isolated than previously
thought. 12z sounding is showing PWs starting to come down, 2" on
last nights 00z sounding and 1.75" on this morning`s. HRL

&&

.SHORT TERM...
(Today through Thursday)
Issued at 311 AM CDT Wed Sep 18 2024

The only thing that sort of defines this trough axis that has been
very slow to move through is in PW values. 00z soundings show this
drier air NE of the area with 1.4" PW at BMX and near 2" at LIX.
Models show this boundary moving very slowing to the coast by late
Thursday. This presents a very good environment for fog production
along with abundant moist soils and rain that fell yesterday,
moisture in the boundary layer is not lacking. There is a very nice
susident dry layer at 955mb which will take the heat radiated from
the sfc. Basically, we should see fog form again this morning, but
unlike past mornings, this could be a bit more dense along and north
of the interstate 10/12 corridor as well as some south shore
locations mainly outside heat islands. And we should have clear
skies through the morning hours until the cloud on the ground
develops. We will watch for this as it should begin to form just
before sunrise. We may need to issue a dense fog advisory if this
becomes the case. With the boundary still to the NE of the area, we
could still see at least isolated sh/ts around and there are some
hints at where the best locations for higher precip numbers. We have
brought precip chances up a bit from the NBM and also tried to give
the highest numbers to the areas that look to have the highest
potential for sh/ts with help from CAMS and synoptic scale models.
Otherwise, by Thursday we should see somewhat lower precip numbers
but may keep isolated along and ahead of this boundary as it lays
along the coast late Thu.

&&

.LONG TERM...
(Thursday night through Tuesday)
Issued at 311 AM CDT Wed Sep 18 2024

Conditions are still conducive for waterspouts today, but this
begins to change as we move into late Thu into the weekend. We will
have a few easterly waves that traverse the gulf late in the weekend
into next week and this will at least enhance rain chances during
that time frame. The large stacked high is beginning to move NE
and will eventually center itself over southern TX by the weekend.
The extended holds some very interesting features. The first is
what will grab headlines which will be the area in the NW
Caribbean that has a 20% chance of becoming a tropical cyclone
over the next 7 days. The other is a very deep fast digging upper
trough into the country as this tropical cyclone is supposed to
start developing. This is what models are advertising to pick this
tropical system up bringing it north then NE. The upper trough
moves so fast that strong modifying is not able to take full
effect. IF this tropical system moves east of the area, it could
help bring this very dry cool air into the area. That is a big IF
at the moment. We will have to see how this works out but at some
point over the next month we should see the first true cold front
move into or through the area.

&&

.AVIATION...
(18Z TAFS)
Issued at 1223 PM CDT Wed Sep 18 2024

VFR at all terminals right now and this will continue through the
forecast period. Some isolated showers are not out of the question
this afternoon and evening, mainly for MCB, GPT, and HUM.

&&

.MARINE...
Issued at 311 AM CDT Wed Sep 18 2024

Winds will be quite light and variable at times over the next
several days. But as we get to the weekend, winds become more stable
and established from the east and rise to around 15kt. Winds and
seas will be higher near and in storms and waterspouts will be
possible with any of this activity into Thu.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  70  89  67  89 /  30   0   0   0
BTR  74  93  71  94 /   0  10   0   0
ASD  73  91  70  91 /   0  10   0   0
MSY  74  89  74  90 /   0  10   0   0
GPT  72  89  70  90 /  10   0   0   0
PQL  72  93  70  94 /  20   0   0   0

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...None.
MS...None.
GM...None.
&&

$$

SHORT TERM...TE
LONG TERM....TE
AVIATION...HL
MARINE...TE