textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 1137 AM CST Sat Nov 29 2025 - Hazardous marine conditions for much of the next 5 days. - Entering a wetter pattern beginning later today into Sunday, with additional periods of rainfall, possibly heavy, Monday night into Tuesday, and possibly again on Thursday.

SHORT TERM

(This afternoon through Sunday) Issued at 1137 AM CST Sat Nov 29 2025

A weak shortwave was moving across Mississippi this morning with a deeper trough over the northern and central Plains States. At the surface, high pressure was centered from Ohio to the Carolinas. Low pressure was centered just northeast of Oklahoma City with a warm front into east Texas. Clouds were increasing across the area this morning, and radar indicates there could even be a few sprinkles of rain over southwest Mississippi. Temperatures were mainly in the 60s.

The lead shortwave should be into Alabama by early afternoon. The main trough axis and surface low will move into the Great Lakes by Sunday afternoon, which will pull a cold front across the area late tonight and Sunday morning. Precipitable water values that were near the 25th percentile this morning (0.6 inches) will increase to about the 50th percentile (0.9 inches) by sunset and the 75th percentile (1.2 inches) Sunday morning. At this point, it appears that any precipitation is likely to be post-frontal stratiform rain, with totals generally below one-half inch. Instability is extremely limited, with very little, if any thunder expected.

High temperatures Sunday will be tricky depending on the timing of the frontal passage at any one location. Areas behind the front are likely to remain in the 50s, while areas ahead of the front (mainly near and south of the I-10/12 corridor) could be as warm as the lower 70s before falling off.

LONG TERM

(Sunday night through Friday) Issued at 1137 AM CST Sat Nov 29 2025

We never really clear out behind the frontal passage on Sunday, with moisture levels remaining high, precipitable water values around 1.25 inches. The next trough in the progressive pattern will move across the lower and middle Mississippi River Valley Monday night and Tuesday. This trough is stronger and further south than the one in the first 24 hours of the forecast. Moisture content will also be higher, with precpitable water values around 1.6 inches, which is at or above the 90th percentile for early December. With a difluent pattern aloft and favorable jet dynamics, low pressure is expected to develop over the Gulf Monday night and race northeastward. Once again, much of the rain is expected to be to the north and west of the front with only a very limited threat of thunder. There will be a band of heavy rainfall to the northwest of the low pressure track, but some uncertainty exactly where this sets up. One to three inches of rain, locally heavier, will be possible with the heavy rain band, but with the rather dry antecedent conditions, not anticipating a Flood Watch with that system as of this time.

Beyond the Tuesday system, the GFS and ECMWF continue to have divergent solutions with the GFS operational runs continuing to bring another system across the area late Thursday into Friday, while the ECMWF keeps the area considerably drier until the weekend.

Through the daytime hours Tuesday, most of the temperature guidance is at least in the ballpark. Have noted that the GFS/ECMWF guidance from the 29/00z run is warmer than the runs from the last couple days, and the NBM numbers will probably end up coming up several degrees in later packages. Won't make changes for now, but have noted the trends.

AVIATION

(18Z TAFS) Issued at 1137 AM CST Sat Nov 29 2025

VFR expected through most of the forecast period. MVFR conditions will onset late tonight as the frontal boundary moves into the area. Some potential for IFR conditions between 12z-18z Sunday, especially at KMCB and KBTR.

MARINE

Issued at 1137 AM CST Sat Nov 29 2025

At least in the near term, will terminate headlines as pressure gradient and cold advection has ended. We'll be back in the hazardous conditions beginning Sunday night, with headlines necessary for much of the period from Sunday night through at least Tuesday night.

PRELIMINARY POINT TEMPS/POPS

MCB 50 57 42 55 / 60 80 40 70 BTR 53 63 46 60 / 50 70 40 70 ASD 52 70 47 64 / 20 50 20 60 MSY 58 72 54 66 / 20 40 20 60 GPT 54 71 50 67 / 10 40 10 50 PQL 49 71 47 67 / 10 40 10 50

LIX WATCHES/WARNINGS/ADVISORIES

LA...None. GM...None. MS...None. GM...None.