520
FXUS64 KLIX 262342
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
642 PM CDT Tue May 26 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 641 PM CDT Tue May 26 2026

- Heavy rainfall continues to be the main weather threat through
  the week. Some of the stronger storms will be capable of
  producing hourly rainfall rates of 1-3" per hour. With mostly
  saturated soils, high rainfall rates even over short periods
  could overwhelm drainage systems, leading to ponding of water in
  low lying and poor drainage areas. Localized flash flooding
  could also result in some roads becoming impassable, mainly in
  areas where the heaviest rain falls, or where multiple storms
  result in longer periods of moderate to heavy rain.

- A Flood Watch will be in effect through 7 PM Tuesday generally
  for areas from the New Orleans metro eastward through the
  Mississippi Coast including the north shore. Elsewhere, the
  flood threat will be lower, though isolated flooding could still
  occur.

- A Flood Watch is in effect for our entire area Wednesday and
  Wednesday evening. Additional Flood Watches may be needed,
  especially Thursday.


&&

.SHORT TERM...
(Now through Friday night)
Issued at 1229 PM CDT Tue May 26 2026

Tonight through tomorrow morning, there will be a lull in shower
and storm activity generally. We are not expecting much if any
rainfall overnight. Looking at the CAMs and global models, there
is an MCS complex moving across western Louisiana tonight, which
could make it into our area by around 12-14z (7-9am). It is
expected to weaken and slow as it approaches the area, which could
cause some training for our northwest areas as it stalls. Some
gusty winds (40-60mph) will be possible with these storms as well
for our northwest areas, but we are not expecting these storms to
be severe.

Flash flooding will be a concern with these storms as
they approach the northwest areas. Flash flooding will also be a
concern for areas east of I-55 as the morning trends in the CAMs
show a consensus boundary that sets up tomorrow around 10am along
a line from Houma to Picayune, including New Orleans and the
northshore of Lake Pontchartrain. So, we have 2 main focus areas
for flash flooding concerns:
the approaching synoptic MCS from the west that is expected to
stall over western areas around 7a-1p CT tomorrow and a stalled
mesoscale boundary for areas east of I-55 that will set up around
10a-6p CT tomorrow. For both of these areas, the concerns and
potential impacts from flash flooding will be the same. Abundant
moisture combined with a decent LLJ, decent instability, and high
PWs (above the 90th percentile for SPC sounding climatology) will
caused enhanced potential for flash flooding issues. Rainfall
rates will be generally 1-3 inches per hour, as these storms will
be highly efficient. This is especially the case for areas that
have seen widespread rainfall over the weekend. Additionally,
minor to moderate rises for area rivers will be expected from
these storms.

Saturated antecedent conditions and favorable flash flooding
conditions will make runoff quicker and enhance flash flooding
impacts. And the high effiency of the rainfall will be of
particular concern for areas that are saturated and for urban
areas, which is at this point our entire area. Though we do have
higher concerns for the MS Coast due to the remarkable rainfall
totals that area has seen over the last few days as well as New
Orleans and Baton Rouge for their urban vulnerabilities.

So, we have discussed the potential for heavy rainfall and the
concerns, but what does this look like in terms of impacts? Well,
we have several concerns. A lot of the potential impacts will be
the same or similar to what we saw over the weekend. So, there is
potential for water over roadways, which could cause some roadways
to be impassable or closed, especially urban or saturated areas.
Of note for New Orleans is the concern for ponding of low-lying
roads, underpasses, and poor drainage locations. Keep in mind that
underpasses will flood before other roadways. And then for river-
adjacent locations, there is concern for water to be approaching
structures along rivers, mainly for the flashier rivers along the
MS Coast.

Thursday into Friday, an MCS will move through the area slowly,
which will enhance flash flooding concerns again. The environment
will still be quite conducive to flash flooding, even moreso than
today or tomorrow. And the timing of these storms will be less
certain, since we are still several days out and CAMs haven`t
fully weighed in. But we would expect concerns similar to the past
few days for Thursday and Friday. MSW

&&

.LONG TERM...
(Saturday through Monday night)
Issued at 1229 PM CDT Tue May 26 2026

Saturday through early next week, there is a lot of model
uncertainty. There are still several days out, so a lot may change
between now and then, especially given the lack of reliabiltiy in
the models lately as they struggle with this pattern. Generally,
ridging looks to build back over the area, and we start to see
more of a typical pattern for this time of year. Afternoon and
evening showers and storms will be expected Saturday, Sunday, and
Monday, which will have some risk of localized flash flooding and
strong storms. We are not expecting severe weather over the
weekend at this time, and generally coverage looks to be moreso
around 30-50%. So, expected isolated to scattered
afternoon/evening showers and storms over the weekend, closer to
our climatology for May. MSW

&&

.AVIATION...
(00Z TAFS)
Issued at 641 PM CDT Tue May 26 2026

VFR conditions across the area predominate as earlier
thunderstorms die out in the overnight hours. TEMPO coding
account for on and off sh/ts activity tomorrow that fires off
again around daybreak and will bring MVFR to possible instances of
IFR wherever storms do build. /Schlotz/

&&

.MARINE...
Issued at 1229 PM CDT Tue May 26 2026

High pressure anchored over the western Atlantic will maintain light
to moderate onshore flow across the local coastal waters. Daily
showers and storms will be capable of producing locally hazardous
winds and seas, with a few cells each day capable of producing winds
in excess of 34 kts over the next few days.

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Flood Watch from Wednesday morning through Wednesday evening for
     LAZ034>037-039-046>048-056>058-064-070-071-076>087-089>100.

     Flood Watch until 7 PM CDT this evening for LAZ039-064-070-
     076>080-087-089>093-098>100.

GM...None.
MS...Flood Watch from Wednesday morning through Wednesday evening for
     MSZ068>071-077-083>088.

     Flood Watch until 7 PM CDT this evening for MSZ077-083>088.

GM...None.
&&

$$

SHORT TERM...MSW
LONG TERM....MSW
AVIATION...DS
MARINE...MSW