Flash Flood Warning 40, NWS New Orleans, LA

Area Forecast Discussion...UPDATED
National Weather Service New Orleans LA
550 AM CDT Mon May 25 2026

...NEW AVIATION...

.KEY MESSAGES...
Updated at 544 AM CDT Mon May 25 2026

- Heavy rainfall continues to be possible with any stronger storms
  into the start of the new workweek. A Flood Watch remains in
  effect through Monday evening for portions of the area generally
  south of a line from Baton Rouge to Bogalusa.

- Some storms will be capable of producing hourly rainfall rates
  of 1-3" per hour. High 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.

&&

.SHORT TERM...
(Now through Wednesday)
Issued at 155 AM CDT Mon May 25 2026

The stubborn upper level pattern continues to remain southerly or
southwesterly with the series of vorts continuing to move over
the region within the flow. Today will be no different. Both
globals and CAMs indicate a potentially wet day, especially east
of the I55 corridor including the MS Gulf Coast. PWATS are well
up there over 2.0" which will support efficient rainfall rates.
Went ahead and continued the FFA through this evening, but the day
shift may need to extend the headline if, indeed, the region gets
a good soaking today with additional heavy rain being a threat on
Tuesday. Speaking of Tuesday, it will remain difficult to
properly time each impulse as it moves downstream over the region,
but another wave looks to move over during peak heating with the
best potential for rainfall again east of the I55 corridor. PWATS
on Tuesday may be just a skosh lower, but still 1.75"-1.85" will
be enough for concern especially with antecedent conditions being
a bit more favorable. Finally, not to sound like a broken record,
but Wednesday the pattern is left unchanged. Again timing will be
tricky, which also makes knowing where the heaviest precip will
fall a bit tricky as well. But a continuation of localized hydro
concerns is anticipated.

As for severe weather potential, overall, the potential will be
very conditional...not zero. The main threat will be gusty winds
with precip loading evident by the highly saturated environment.
And finally temperatures will remain a touch below average through
the short term as again cloudiness, rainfall, lower
heights/thicknesses, and mesoscale boundaries will help limit
duration of heating, though if there is a break in the afternoon
hours where sun pops through the cloud cover, there will be some
decently strong and rapid surface heating. (Frye)

&&

.LONG TERM...
(Wednesday night through Sunday)
Issued at 155 AM CDT Mon May 25 2026

The latter half of the week will inherit much of the same broad,
southwesterly flow regime aloft of earlier in the weak as the upper
troughing within the subtropical jet lingers. This will continue to
enhance rainfall chances with largely summertime diurnally-driven
convective patterns setting up. The qausi-rex block regime with
ridging over southern Canada will keep upper troughing and stubborn
subtropical jet parked across the southern U.S. into the end of the
week with the only nuanced difference potentially being propagation
of the upper trough toward the SE CONUS. This would promote more
westerly to northwesterly flow that could relatively lower PWATs
from their current near-daily maximums between 1.9 to 2.1 inches.
Either way, PoPs will be a mainstay in the forecast particularly for
the afternoons each day through the forecast period. Temperatures
will be near average through the period with highs in the mid 80s
and lows in the upper 60s and lower 70s.

A tease beyond Day 7 in the global ensembles does allude that this
unsettled weather pattern could eventually break early next week
where a stronger, more textbook, rex block attempts to establish
across the north-central CONUS and strengthen east coast troughing
that could help pivot upper-level flow into a more northwesterly
orientation and promote advection of drier, continental air. We'll
see if this solution becomes more consistent in the coming days.
(TJS)

&&

.AVIATION...
(12Z TAFS)
Issued at 544 AM CDT Mon May 25 2026

Mostly VFR conditions expected during the daylight hours outside
of convection. Early morning and overnight, MVFR or lower
CIGs/VIS will be possible especially if convection develops at
night later in the period. Otherwise, surface winds will remain
light to moderate and mostly out of the south...but may be a bit
more erratic around convection. (Frye)

&&

.MARINE...
Issued at 155 AM CDT Mon May 25 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. (Frye)

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Flood Watch through this evening for LAZ039-046>048-056>058-064-
     070-076>087-089>100.

GM...None.
MS...Flood Watch through this evening for MSZ077-083>088.

GM...None.
&&

SHORT TERM...RDF
LONG TERM....TJS
AVIATION...RDF
MARINE...RDF

Preliminary Local Storm Report
National Weather Service New Orleans LA
853 AM CDT Mon May 25 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0835 AM     Marine Tstm Wind 83 SE Venice            28.52N 88.29W
05/25/2026  M53 MPH          GMZ575             LA   Mesonet

            Mesonet station KIKT 82 SE Venice measured a
            wind gust of 53mph or 46kt.

&&

JZ

Special Weather Statement
National Weather Service New Orleans LA
905 AM CDT Mon May 25 2026

LAZ089-090-092-251500-
Central Plaquemines LA-Central Jefferson LA-Upper Plaquemines LA-
905 AM CDT Mon May 25 2026

...A STRONG THUNDERSTORM WILL IMPACT PORTIONS OF NORTHWESTERN
PLAQUEMINES PARISH THROUGH 1000 AM CDT
...

At 904 AM CDT, Doppler radar was tracking a strong thunderstorm
capable of producing waterspouts over marine areas near Lafitte, or 9
miles south of Belle Chasse, moving northeast at 20 mph.

HAZARD...Waterspouts and winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Waterspouts can easily overturn boats and create locally
         hazardous waters. Gusty winds could knock down tree limbs
         and blow around unsecured objects.

Locations impacted include...
Belle Chasse and Terrytown.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

If on or near marine areas, get out of the water and move indoors or
inside a vehicle. Remember, lightning can strike out to 10 miles from
the parent thunderstorm. If you can hear thunder, you are close
enough to be struck by lightning. Move to safe shelter now! Do not be
caught on the water in a thunderstorm.

&&

LAT...LON 2971 9005 2972 9008 2990 9001 2989 8999
      2991 8997 2989 8993 2979 8986 2966 9001
TIME...MOT...LOC 1404Z 220DEG 16KT 2971 9002

WATERSPOUT...POSSIBLE
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

Zeringue

Preliminary Local Storm Report
National Weather Service New Orleans LA
1005 AM CDT Mon May 25 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1005 AM     Flash Flood      2 W New Orleans         29.97N 90.11W
05/25/2026                   Orleans            LA   Public

            Carrollton Underpass is closed due to street
            flooding according to NOLA Streetwise.

&&

JZ

Preliminary Local Storm Report
National Weather Service New Orleans LA
1007 AM CDT Mon May 25 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1006 AM     Flash Flood      2 NE Bridge City        29.95N 90.14W
05/25/2026                   Orleans            LA   Public

            Intersection of Oak St and Eagle St flooded
            according to Streetwise NOLA.

&&

JZ

Preliminary Local Storm Report
National Weather Service New Orleans LA
1010 AM CDT Mon May 25 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1010 AM     Flash Flood      4 WSW East New Orleans  30.04N 89.99W
05/25/2026                   Orleans            LA   Public

            Intersection of Curran Blvd and Benson St
            flooded according to Streetwise NOLA.

&&

JZ

Preliminary Local Storm Report
National Weather Service New Orleans LA
1011 AM CDT Mon May 25 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1011 AM     Flash Flood      4 SW East New Orleans   30.01N 89.97W
05/25/2026                   Orleans            LA   Public

            Street flooding along Old Gentilly Rd
            according to Streetwise NOLA.

&&

JZ