textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 531 AM CST Fri Dec 12 2025 - Little or no rain expected through Saturday. Higher rain chances Saturday night into Sunday morning with a cold front.

- The coldest air of the year will bring dangerous wind chills and a widespread freeze to the area Sunday night into Monday morning.

- Strong winds and dangerous seas are expected Sunday into Monday after a strong cold front moves through.

UPDATE

Issued at 115 AM CST Fri Dec 12 2025

Updated ZFP to lower this morning's low temperatures, as current temperatures at 1 AM CST were several degrees below forecast lows, near the NBM 5th percentile. While high pressure is sliding off to the east, it may be several more hours before temperatures moderate in most of the area. Noted that MSY and NEW reporting southeast winds, while most of remainder of the area is calm. Could see temperatures start to rise toward sunrise. RW

SHORT TERM

(Tonight through Saturday night) Issued at 1030 PM CST Thu Dec 11 2025

The surface high pressure that is sitting east of us will move further eastward through the day on Friday. In the upper levels a southern stream shortwave moving across Texas will push into our area on Saturday. This happens while a much larger and deeper trough swings across the Great Lakes region. All of this helps keep us in an onshore flow, aiding to increase the moisture across the areas. This immediately shows in our RH values Friday afternoon, on the order of ~70% which is up from the 35-40% Thursday afternoon. Some very minor rain chances creep into western areas Friday afternoon, ~15-20%, while a little bit better of chances arrive later in the day Saturday, up to 25-30% for northern areas.

That increased moisture that we will see helps the environment be more conducive to fog, which is our main concern of the short term period. Friday night into Saturday morning looks to have a good chance at widespread fog as we see light winds and that moisture thanks to the onshore winds. The HREF is already hitting on this potential very hard, along with several other models. If this trend continues a Dense Fog Advisory may be needed with the forecast package tomorrow.

LONG TERM

(Sunday through Thursday night) Issued at 1030 PM CST Thu Dec 11 2025

The start to the long term brings our best chance of rain throughout the forecast period, with a strong cold front associated with that upper level deep trough approaching our area. The early morning hours on Sunday will see a 40-50% chance of rain for northern areas and a 15-25% chance for further south areas. This is expected to be a pretty light rain in the areas it does fall, with no real threat of strong storms or organized convection. After this cold front passes later in the day Sunday, we will see upper level ridging building in from the west. This will be paired with a decent area of high pressure at the surface, sitting to our NE. These features bring us drier weather through at least mid-week. Global models are hinting at another southern stream trough making its way towards us towards mid to late week, but with not a ton of agreement in the models not going to stray from NBM at all.

Now getting into the real threat of the long term period, the cold. Sunday's cold front will be a pretty decent one, bringing a surge of cold air in behind it. Monday morning MinTs across areas north of the lake and coastal MS are sitting in the low to mid 20s with MinTs near freezing south of the lake. Wind chills north of the lake are expected to be in the teens with areas south of the lake likely seeing the low to mid 20s. Some sort of cold weather hazard will definitely be in place Monday morning, at this point looking to be a Cold Weather Advisory but given we are still a few days out and need to watch trends I wouldn't rule out an Extreme Cold Warning for some areas.

AVIATION

(12Z TAFS) Issued at 531 AM CST Fri Dec 12 2025

All forecast terminals were VFR at forecast issuance, although there were a few other airports reporting patches of fog at times. Low level moisture is beginning to return, but is more noticeable west of the Atchafalaya River. Expect MVFR ceilings to spread across the area from west to east later today, potentially prior to 18z. The MVFR ceilings are expected to continue through the evening. Expect conditions to lower to IFR toward sunrise Saturday. Main question at that point is whether it'll be ceilings or visibilities. Moisture will be increasing over the next 24 hours, but whether we get into a definitive advection fog regime is up for question as surface dew points look to be in the mid and upper 50s overnight tonight. That's pretty close to where the water temperatures are. We'll keep monitoring it.

MARINE

Issued at 1030 PM CST Thu Dec 11 2025

Light onshore winds of 10 knots or less and calm seas of 2 feet or less will persist over the waters through Saturday as a broad area of high pressure remains centered over the region. A rapid change in conditions will then take place Saturday night and Sunday morning as a very strong cold front moves through. Winds will turn northerly and increase in speed to between 25 and 35 knots with higher gusts from Sunday afternoon through Monday morning. There is a decent probability that headlines will be issued for the waters over this time period due to high winds and rough seas anticipated. Another high will then quickly settle over the area on Tuesday, and this will allow winds to turn more easterly and fall back to less than 10 knots. Seas will also begin to subside as the winds decrease Monday night into Tuesday.

PRELIMINARY POINT TEMPS/POPS

MCB 69 53 70 44 / 10 10 20 60 BTR 73 56 74 50 / 20 10 20 50 ASD 72 53 73 49 / 10 10 10 30 MSY 74 58 75 53 / 20 10 10 20 GPT 69 55 70 51 / 10 10 20 30 PQL 71 52 73 48 / 0 10 20 30

LIX WATCHES/WARNINGS/ADVISORIES

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