An upper level system moved across the area very slowly on March 29th. The flow pattern in the upper levels were quite conducive for sustained thunderstorm growth.
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS LIX wrote it up.
An upper level system moved across the area very slowly on March 29th. The flow pattern in the upper levels were quite conducive for sustained thunderstorm growth. Add in ample moisture in place to produce moderate to heavy rain and the environment was prime for producing flash flooding. Training thunderstorms in the Baton Rouge Metro area resulted in flash flooding.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS New Orleans, LA wrote its last area forecast discussion before the first event at Mar 29, 1:21 PM CST, 3 hours 49 minutes earlier.
Area Forecast Discussion
National Weather Service New Orleans LA
221 PM CDT Sat Mar 29 2025
...New SHORT TERM, LONG TERM, AVIATION, MARINE...
.SHORT TERM...
(This evening through Sunday night)
Issued at 120 PM CDT Sat Mar 29 2025
Tonight through Sunday mid-day, several rounds of storms will move
through the area, enhancing rain chances significantly for the
region. Storms will start to fire up late afternoon today and move
through the area in several waves through the evening and overnight
hours. PW values are well above the 90th percentile for the SPC
sounding climatology, so rainfall should be highly efficient. There
is plenty of moisture throughout the atmospheric column (>75% RH for
mid and low levels). There are ongoing deep warm cloud layer
processes in place for tonight. And generally, the shear seems
fairly low for this area. The storms that have developed so far this
morning in our marine areas have been quite slow-moving as well,
evidencing an environment favorable for backbuilding and training.
So, overall, we are looking at a very favorable environment for
flash flooding this evening into the overnight hours. The widespread
totals in the models are generally around 1-3 inches for the area as
a whole. HREF runs and CAMs are showing high probabilities (>40%) of
seeing localized amounts of rainfall 5-7+ inches with even some
indications that 10" could be possible in 1-2 locations. WPC has
outlooked us in a Moderate (3 out of 4) Risk of Heavy Rainfall as a
result. We have a Flood Watch in effect for all of our areas for
tonight through 12Z Sunday.
The biggest unknown at this point is going to be location.
We are confident that storms will develop and that they will have
the potential to be stationary, which could result in 5-7+ inches or
more of rainfall; however, we have little confidence in the specific
areas that will receive the heaviest rainfall. And as we all know
along the Gulf Coast when speaking about heavy rainfall, location is
critical. If the heaviest rainfall occurs in less vulnerable
locations, like the Atchafalya Basin, swampy areas, or more rural
locations, then there will likely not be as many impacts from this
system. However, the scenario that we are most concerned about that
is very much a real possibility looking at the models, would be if
the rainfall occurs in our more vulnerable and urban locations (i.e.
Thibodaux, New Orleans metro, Baton Rouge metro, northshore of Lake
Pontchartrain, or the Mississippi Coast). If the storms move over
these locations, drainage capacity would be overwhelmed, leading to
significant impacts such as widespread street flooding with numerous
roads becoming impassable due to high water, or even some buildings
becoming flooded. An additional concern with the timing of the
rainfall is that the best timing will be this evening into the
overnight hours, which means that a lot of this flooding if it
occurs would be at night. Nighttime flooding would be particularly
dangerous, since it is more difficult to ascertain depth of the
water as well as generally see flooding at night.
Sunday, looking at the models, there will be a break in the rainfall
from the morning hours through the afternoon hours. Scattered
showers will be possible during the late afternoon and early evening
hours on Sunday. These storms should be fairly isolated to scattered
and would be more popup/off and on in nature, and the main risks
would be lightning and gusty (30-50mph) winds. The main timing for
the scattered storms will be 2p through sunset (~6/7p) generally.
There will be another break in the rainfall Sunday night from sunset
Sunday through around ~2am Monday morning. A frontal system is
expected to move through the area Monday morning. The general timing
is still quite a bit uncertain, though admittedly, the models have
come into better agreement with each other. Overall timing of the
frontal system looks to be approaching our area around 2a-4a
timeframe (Euro is earlier still while GFS ensembles are a little
later) and move through the area fairly quickly, exiting the area by
mid-day Monday. The main threats associated with this system will be
gusty severe winds (60+mph) and an embedded tornado or two cannot be
ruled out. There is still a lot of uncertainty with this system and
a lot can change in the next 12-24 hours, so we will be monitoring
this closely. MSW
&&
.LONG TERM...
(Monday through Friday night)
Issued at 120 PM CDT Sat Mar 29 2025
Monday through Wednesday morning, zonal flow will
dominate the upper level pattern. Southerly flow will continue to
dominate Tuesday and Wednesday. As a result of the continue warm air
advection and increasing humidities, afternoon showers and storms
will be possible Tuesday from about 2p through sunset. These storms
will be scattered popup type showers in nature. The main threats
looks to be gusty winds (30-50mph), lightning, and locally heavy
rainfall.
Wednesday through Friday morning, high pressure builds over the
area. Looking at the models, conditions will be fairly dry overall
during this time. Persistent southerly flow will allow for continued
warm air advection over the region. And temperatures will be quite
warm with highs in the mid 80s for the area with some locations
approaching 90 degrees for Wednesday through Friday. MSW
&&
.AVIATION...
(18Z TAFS)
Issued at 120 PM CDT Sat Mar 29 2025
MVFR conditions prevail at all area airports. Conditions at area
airports will stay at MVFR with brief drops to IFR conditions due
to rounds of showers and storms moving through the area late this
afternoon through the evening and overnight hours and PROB30
groups are in the forecast. These MVFR/IFR flight conditions will
remain through the end of the forecast period, since the rounds of
showers and storms are expected to linger into the morning hours
tomorrow. MSW
&&
.MARINE...
Issued at 120 PM CDT Sat Mar 29 2025
Saturday through Tuesday morning winds will be southerly
and moderate (10-15kts). Tuesday, winds will be easterly and
moderate (10-15kts). Wednesday through Friday, winds will be strong
(15-20kts) and southerly in direction. MSW
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 65 84 67 82 / 40 30 70 70
BTR 68 86 70 84 / 30 20 60 60
ASD 67 84 70 84 / 70 30 30 80
MSY 69 84 71 84 / 60 20 30 70
GPT 65 77 67 81 / 70 50 20 80
PQL 65 80 67 82 / 60 50 20 80
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Flood Watch through Sunday morning for LAZ034>037-039-046>048-
056>060-064>071-076>090.
GM...None.
MS...Flood Watch through Sunday morning for MSZ068>071-077-083>088.
GM...None.
&&
SHORT TERM...MSW
LONG TERM....MSW
AVIATION...MSW
MARINE...MSWThe Hammond radar (KHDC), 82 km away, was scanning. The volume nearest the first event began at 23:09 UTC.
12 flash flood, 1 strong wind. Local standard time, as filed.
Louisiana Highway 68 covered in high water. Several flooded vehicles reported.
Louisiana Highway 955 covered in water. Stalled vehicles due to the high water.
US Highway 61 covered in high water. Several vehicles flooded out and stalled on the highway.
Water surrounding homes on Plains-Port Hudson Road.
Several homes with water surrounding them based on photos sent by trained spotter on Plains Port Hudson Road.
High water covering roads. Depth is halfway up car tires.
Street flooding from high water with vehicles reported stranded and stalled out.
Street flooding reported at the intersection of Airline Highway, Bluebonnet Blvd., and Coursey Blvd. in Baton Rouge.
A tree fell on a home during a wake low event in Baton Rouge.
High water covering Summa Ave. between Essen Lane and Picardy Ave.
High water covering the road at Blecker Dr. and Pine Crest Dr. in Baton Rouge.
High water covering the road at the intersection of Essen Lane and United Plaza Blvd. in Baton Rouge.
High water covering the road at Toulon Dr. and Cabot Ave. in Baton Rouge.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Louisiana in 2025Every state in 2025This day in weather historyWarnings in Louisiana, March 2025
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1256332, 1256334, 1256335, 1256336, 1256338, 1256339, 1256617, 1256619, 1256626, 1256620, 1256621, 1256623, 1256625.