Flash Flood Warning 48, NWS New Orleans, LA

Area Forecast Discussion
National Weather Service New Orleans LA
150 PM CDT Thu May 28 2026

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

.KEY MESSAGES...
Updated at 146 PM CDT Thu May 28 2026

- River flooding in Pearl River Co and MS Coastal Basins will be
  main impacts from heavy rain this evening.

- A slightly drier pattern going into the upcoming weekend,
  however, isolated to scattered afternoon showers and storms will
  remain possible. With rain chances a bit lower, temperatures
  later this weekend will climb close to or exceed 90 degrees with
  heat indicies approaching 100.

&&

.SHORT TERM...
(Now through Sunday night)
Issued at 146 PM CDT Thu May 28 2026

A very amplified upper level flow pattern is in place across the
country with troughs on the West and East coasts and a ridge between
them on the east side of the Mississippi River Valley. A shortwave
trough embedded within the eastern side of the West Coast one is
currently tracking into the ridge and slowly weakening. Regardless,
deep layer moisture has been drawn northward from and mid level flow
as this feature moved SW to NE across TX and AR. PW on this
morning's KLIX sounding was 2.28" which is quite impressive for even
late may. This did result in quite heavy rainfall over Pearl River
Co and northern portions of coastal MS counties. The good news is
radar trends over the last few hours indicates that the heaviest
rain has now shifted northward. While there may be some
redevelopment closer to the trough across Baton Rouge Metro and
northwestward, coverage and rain rates should be much less
intense there.

A decent pocket of drier air is forecast to follow in the wake of
that shortwave and slide across the CWA Friday. It won't be enough
to stop all convection but should be a noticeable decrease in
rain and thunderstorm coverage as well as heavy rain threat.

MEFFER
&&

.LONG TERM...
(Monday through Wednesday night)
Issued at 146 PM CDT Thu May 28 2026

Finally a pattern change coming this weekend into early next week.
As the shortwave nearby today dissipates, upper level high pressure
will build in across the northern Gulf Coast. This will both drop
POPs down to more typical scattered afternoon thunderstorm coverage
as seen in early summer patterns as well as allow for temps to warm
up. Should see highs in the mid to upper 90s. Combine that will
dewpoints in the 70s to yield heat indices well into the mid 90s,
possibly touching 100 degrees this weekend.

MEFFER
&&

.AVIATION...
(18Z TAFS)
Issued at 146 PM CDT Thu May 28 2026

Outside of thunderstorms, MVFR to VFR are the dominate conditions at
terminals. Where showers and storms interact with local terminals,
expect at least brief VIS/CIG reductions. Latest radar shows swath
of rain northeast of a KMSY to KBTR line. Once that rain shield
shifts north, meso models suggest the rest of the day will be pretty
quiet from convective standpoint. Some light fog may develop near
terminals that received rain today and bring VIS down into the 4-6sm
range.

MEFFER
&&

.MARINE...
Issued at 146 PM CDT Thu May 28 2026

A surface ridge will begin developing over the southeastern Gulf
tomorrow. This will maintain onshore flow for local coastal waters.
A deep upper level trough will dig southward across the Eastern
Seaboard Sunday into Monday. This will shift that ridge westward and
attempt to send a backdoor front to the coastal waters. Latest
guidance suggests that the boundary stalls right as it reaches the
MS sound due to the proximity of the trough axis in relation to the
local area. Thus, expect wind field to weaken considerably next week
due to weak pressure pattern in place. 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.

MEFFER
&&

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

SHORT TERM...ME
LONG TERM....ME
AVIATION...ME
MARINE...ME