052
FXUS64 KLIX 041938
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
138 PM CST Thu Dec 4 2025

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

.KEY MESSAGES...
Updated at 1208 PM CST Thu Dec 4 2025

1. An area of low pressure near the coast will bring widespread rain
and embedded thunderstorms to the area today through Saturday
morning. 3-day rainfall totals will generally be 1.5" to 3" along
the I-10/12 corridor with locally higher amounts as high as 6"
especially west of I-55.

2. There is a marginal threat of excessive rainfall with this system
today where locally higher rain totals of 2" to 4" in a
approximately 6 hour period could result in flash flooding of
urban and poor drainage areas. Locally higher amounts upwards of
5" cannot be ruled out for the rest of the day.

3. The slow-moving frontal boundary associated with this low will
clear land areas tonight. Drier air filtering in will lower
rainfall rates and reduce the risk for excessive rainfall and
flash flooding. Additional rainfall of up to 3" could occur mainly
along and east of the I-55 corridor. However, most areas are
likely (>50%) to see between 0.5" and 1.5" with scattered shower
activity Friday through Saturday.

&&

.SHORT TERM...
(This evening through Friday night)
Issued at 1208 PM CST Thu Dec 4 2025

The entire area has at least seen some rainfall today as a surface
low pressure makes its way along the northern Gulf coast. A 925mb
frontogenetic band that set up across the Florida Parishes
produced localized rainfall amounts of 5-6 inches this morning.
Since then, that main banding has moved off to the east more
progressively than this morning and has mostly pushed offshore of
the MS Coast. Another 925mb frontogenetic band is seeming to set
up across the Atchafalaya Basin this afternoon with lesser rain
rates of 0-5-1 inch per hour. These rates are lower than what we
saw this morning with the heavy rain across the Florida Parishes,
but this one seems like it will affect more populated areas such
as Baton Rouge and its surrounding areas. The rain rates as they
stand now would not be much of an issue, but if that banding does
intensify, then we could see a renewed flash flood threat, mainly
for urban areas near and south of Baton Rouge. Rain totals with
this new band will likely be in the 1-2 inch range. Drier mid-
level air looks to approach the area from the northwest by 7pm,
pushing the rain eastward with it. So, expect most of the rain to
be out of the area by midnight tonight as that drier air moves in.

Drier air at 850mb looks like it will stick around from tonight
and through Friday. This will bump down overall PW values from
1.7-1.8 inches today down to 1.3-1.4 inches (in between the 75th
and 90th percentile for this time of year). This drier air will
look to keep rain mostly scattered throughout the day tomorrow.
Can`t totally rule out a band or two across the area, but
rain totals with those, if they form, would be up to an inch of
rain. Also with the main low pulling away from the area, winds
will continue to relax in response to this. So, instead of a
cloudy and rainy day such as today, it`ll mainly be a cloudy day
tomorrow with scattered showers, not widespread.

&&

.LONG TERM...
(Saturday through Wednesday night)
Issued at 1208 PM CST Thu Dec 4 2025

Another impulse in the southwesterly mid-level flow looks to come
from the Baja Peninsula and track across northern Mexico and into
the northern Gulf Saturday evening and into Sunday. This impulse
will spin up another low pressure in the Gulf by Saturday night.
This will help to increase PW back to 1.8-2 inches along the SE LA
coast. Yet another frontogenetic band looks to form with this
low, but way farther south along the SE LA coast as well, so a
narrow band of higher rainfall of 2-4 inches is expected late
Saturday and into Sunday. thankfully, with this band expected to
set up along the coast, there is very little flash flood threat
due to those areas being mostly wetlands and marshes.

Drier upper-level air will filter into the area starting Sunday
afternoon as an impulse pushes southward across the southern
plains. This impulse also pushes a cold front coming through the
area on Sunday afternoon, effectively sweeping any rain still left
over from the repeated rounds of rain over the weekend. With the
cold front, we will see our next shot of freezing temperatures
Monday night and Tuesday morning. Since we have already had at
least 2 freezes this season, there will not be freezing headlines,
but we are expecting freezing temperatures across portions of the
northern areas.

Timing, strength, and positioning of the next trough that will
traverse the middle parts of the country mid-week differs a lot in
the medium-range guidance. All of those things will have
implications on if we see rain at all and how warm we get towards
the end of the week. As models get into better alignment, the
forecast will become more refined pointing one way or another.

&&

.AVIATION...
(18Z TAFS)
Issued at 1208 PM CST Thu Dec 4 2025

IFR ceilings and periods of light to moderate rain has persisted
throughout the whole day today in association with a surface low
pressure in the northern Gulf. Expect the IFR ceilings to hang
around at all terminals throughout at least the end of this
forecast period. The light to moderate rain is expected to become
more scattered in nature beyond 03z tonight. So, beyond this
evening, the main impact will be the IFR ceilings across the area
lasting through this forecast period.

&&

.MARINE...
Issued at 1208 PM CST Thu Dec 4 2025

Winds have stayed elevated east of the Mississippi River as a
developing surface low moves across the coastal waters. This will
have multiple impacts with Small Craft Advisory conditions expected
Thursday into Friday. With the wind direction being primarily out of
the east, minor coastal flooding is expected mainly for St. Bernard,
eastern Orleans, southeastern St. Tammany parishes, as well as
coastal Hancock and Harrison counties. Winds will relax and return
to offshore late Friday and then more variable on Saturday with the
passage of another weak sfc low. A frontal passage on Sunday night
will bring another push of strong offshore winds on Monday which
could prompt small craft headlines for much of the coastal waters.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  42  50  44  56 /  70  60  60  60
BTR  44  52  46  59 /  70  60  70  60
ASD  44  56  44  59 /  80  40  70  80
MSY  51  57  51  61 /  70  40  70  80
GPT  48  57  47  59 /  80  40  80  80
PQL  45  58  44  59 /  80  40  70  90

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Coastal Flood Advisory from 6 PM this evening to 6 AM CST Friday
     for LAZ070-076-078.

GM...Small Craft Advisory until 6 AM CST Friday for GMZ530-532-534-
     536-538-555-557-577.

MS...Coastal Flood Advisory from 6 PM this evening to 6 AM CST Friday
     for MSZ086-087.

GM...Small Craft Advisory until 6 AM CST Friday for GMZ532-534-536-
     538-555-557-577.

&&

$$

SHORT TERM...JZ
LONG TERM....JZ
AVIATION...JZ
MARINE...JZ