542
FXUS64 KLIX 110827
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
327 AM CDT Mon May 11 2026

...New UPDATE...

.KEY MESSAGES...
Updated at 323 AM CDT Mon May 11 2026

- Moderate to High confidence in showers and thunderstorms during
  the afternoon and evening, with localized flooding and a few
  strong to severe storms possible.

- Finally start to dry out Tuesday as ridging builds into the
  area. Expect temperatures to increase again by mid to late week.

- Areas of dense fog in the Mississippi coastal counties and the
  Pearl River Basin this morning. Dense Fog Advisory in effect
  until 9 AM CDT.

&&

.UPDATE...
Issued at 323 AM CDT Mon May 11 2026

Observations and traffic cameras indicated development of areas of
dense fog in Pearl River Basin, St. Tammany parish and the
Mississippi coastal counties since 130 AM CDT. Have opted to issue
a small Dense Fog Advisory for that area until 9 AM CDT. Should
burn off fairly quickly once we start heating up. RW

&&

.SHORT TERM...
(Now through Wednesday)
Issued at 105 AM CDT Mon May 11 2026

Main upper low remains over eastern Canada. There is a shortwave
this morning over Oklahoma and east Texas. An upper ridge was
over the Intermountain West northeastward into the Canadian
Prairie Provinces. Another upper trough was off the Pacific Coast.

At the surface, a frontal boundary extended from Nashville to near
Alexandria to San Antonio. Most thunderstorm activity at midnight
was over Texas, but there were scattered showers and thunderstorms
between Jackson and Hattiesburg moving southeast. Temperatures
locally at midnight were in the upper 60s and lower 70s.

Our airmass locally remains fairly moist and unstable, with
precipitable water values near 1.5 inches, which is around the
75th percentile. That, however, is considerably lower than the
nearly 2 inch precipitable water values we had Friday
night/Saturday when the heaviest rain occurred.

We do have one more round of showers and thunderstorms to contend
with as the shortwave over Oklahoma and Texas, along with the
frontal boundary, still has to transit the area this afternoon
and tonight. Most of the convection allowing models don`t show
much development of thunderstorms until around midday, as a fairly
extensive cirrus deck may slow heating a bit. Convective
temperatures are expected to be in the upper 70s to lower 80s. The
main concerns with any strong thunderstorms will be potential for
damaging winds, although marginally severe hail can`t entirely be
ruled out. While we don`t anticipate the type of rainfall amounts
we saw Friday and Saturday, as saturated as the ground is in most
of the area, it won`t take nearly as much rain to cause issues.
Current estimates are for around an inch of rainfall with locally
higher amounts. Since much of the area has had some time to drain
since Saturday`s heavy rain, we should be able to handle forecast
rain amounts. Rain should end during the evening, if not sooner.

Tuesday and Wednesday are expected to be dry with mostly sunny
skies. Highs should get well into the 80s, and may even touch 90
on Wednesday. Overnight lows will be in the 60s.

&&

.LONG TERM...
(Wednesday night through Sunday)
Issued at 105 AM CDT Mon May 11 2026

Little change in thinking from the previous forecast packages as a
strong deep layer ridge axis dominates the region through Saturday
night.  Ample subsidence in the mid and upper levels will both warm
temperatures and lower humidity aloft.  The end result will be a
very strong mid-level capping inversion around 700mb that will
effectively limit cloud development to 10k feet or less through the
end of the week. These fair weather cumulus clouds will form each
afternoon during peak daytime heating hours. In the low levels, an
onshore flow will be in place, and this will allow dewpoints to
gradually increase through the week. As a result, despite the very
dry air in place aloft, conditions will turn increasingly warm and
muggy as we move through the long term period. Temperatures will
climb into the mid to upper 80s each afternoon and max heat index
values will peak near 90 degrees. Given the early time period for
this heat, there is a minor to moderate heat risk for portions of
the area on Friday and Saturday. Overnight lows will provide some
relief as clear skies allow for decent radiational cooling each
night. Overnight lows will provide some respite as they dip into
the low to mid 60s over inland areas the upper 60s along the coast
each night through the weekend. Light winds and saturated soils
will also be conducive to patchy fog development each night,
especially over more inland areas.

There are some minor model differences that arise as we move into
Sunday and Sunday night.  The GFS keeps the strong mid to upper
level ridge axis in place over the area resulting in a continued dry
and warm forecast. However, the ECMWF is now showing the ridge axis
shifting slightly to the east.  This weakens the mid-level inversion
just enough to support some isolated shower and thunderstorm
activity Sunday afternoon during peak heating hours.  For now, the
forecast continues persistence indicating a dry and warm pattern
through the entire weekend.

&&

.AVIATION...
(06Z TAFS)
Issued at 105 AM CDT Mon May 11 2026

Another round of fog and low stratus will be the main forecast
concern through the overnight and early morning hours of the
forecast period. This next round of fog and low stratus will
develop due to the combination of light winds, high relative
humidity, and very saturated soils. The main concern that may
detract from the fog potential is a deck of cirrus approaching
from the west. The most likely terminals to be impacted by very
low conditions would be KGPT and KASD, and that would be in the
next few hours before higher clouds blanket the area. Will
continue to monitor, and expect that amendments will be necessary
overnight.

After 14z, increasing boundary layer mixing will allow any fog to
clear and the low stratus deck to lift to between 1000 and 2000
feet. Further mixing by 18z will result in a scattered cumulus
field at around 2500 to 3500 feet. Thunderstorm activity will also
begin to fire up in advance of an approaching frontal boundary
after 18z, and this is reflected by PROB30 or TEMPO wording at
nearly all of the terminals after 18z. The convection will produce
lightning, locally strong wind gusts, and reduced visibilities as
it moves over a terminal. Most convection should dissipate during
the 00z to 06z timeframe, but it might take until the daytime
hours Tuesday before we lose most cloud cover.

&&

.MARINE...
Issued at 105 AM CDT Mon May 11 2026

South to southeast winds of 10 to 15 knots will persist overnight.
Anticipating one more rounds of storms this afternoon and
evening with some strong to severe storms possible across marine
waters. Main threats will be wind gusts greater than 34 knots and
waterspouts. A frontal boundary will move into the waters Monday
night, bringing moderate offshore winds through Tuesday.
Otherwise, marine conditions through the rest of the workweek
appear to remain rather benign.

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Dense Fog Advisory until 9 AM CDT this morning for LAZ039-076-
     079-080.

GM...None.
MS...Dense Fog Advisory until 9 AM CDT this morning for MSZ077-
     083>088.

GM...None.
&&

$$

SHORT TERM...RW
LONG TERM....PG
AVIATION...RW
MARINE...RW