textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 519 AM CST Thu Jan 22 2026

- A Winter Storm Watch has been issued for southwest Mississippi and a portion of southeast Louisiana. A potentially significant freezing rain event is becoming more likely over the northern tier of the forecast area. Rain will transition to freezing rain late Saturday across portions of southwest Mississippi and the adjacent Florida Parishes. The chance of accumulating ice in those areas Saturday night remains at 40-60%. Areas along the I-12 corridor west of I-55 at about a 20-25% chance. Icing across the Northshore, Southshore, and coastal MS is unlikely at this point (0-10% chance), but we will continue to monitor for trends.

- After the threat of freezing rain, the cold Arctic airmass brings coldest air of this winter season with lows in the upper teens in northern portions of the forecast area to near freezing down to Grand Isle. This is basically Sunday morning through Tuesday morning. Cold weather headlines will likely be needed.

UPDATE

Issued at 519 AM CST Thu Jan 22 2026

Marine Dense Fog Advisory has been issued for mainly the nearshore coastal waters including the sounds and lakes through 11am today. SST numbers are around 55F for these waters and 50F for the Miss River. Dew pt temps are near 60F making this a delta of 5 to 10F with 98%+ humidity. These areas should be capable of dense fog this morning with criteria 1NM or less with the Miss River most vulnerable. But most of these locations should become 1/4NM by sunrise today. Winds are variable to non-existant across land locations, and since this has to go by advective properties for land zones, it will be hard to get this fog inland very far but those on the immediate coast could get some dense fog if the light wind is oriented inland. The Causeway Bridge will also see some of this dense fog form mainly from centerpoint to north approach.

UPDATE

Issued at 211 AM CST Thu Jan 22 2026

A Winter Storm Watch has been issued beginning Saturday night at midnight. Confidence is building for some ice accumulations in areas of SW Miss and a portion of SELA late Saturday night ending Sunday evening. Amounts of icing and how far south it will reach is still questionable and will likely change with successive forecasts. The line still lookse to be along and north of BTR to MCB but we have added one more line of parishes adjacent and south of this line for a buffer. Since it is only a watch, it gives some wiggle room to add or subtract areas as this scenario becomes more focused.

Two global model suites(GFS and CMC) are showing a similar trend and have not changed their output extensively since showing this scenario several days ago. The Euro is the only model that has aggressively changed its output. 3 of 10 NBM ensemble members continue to agree with these two(GFS and CMC/Canadian) global models as well. Two H3 jet pulses will help support this scenario. The second, that moved overhead of upper air site PASY at 12z Wed(6a Wed) and 00z Thu(6p Wed), did not get sampled because, although previous releases before this were successful, these were the only two times that this site did not get a successful release. So we still don't have a good sample of this jet core in either of the two pulses. The first of these two jet max areas is moving around the top of the upper ridge over Alaska and since this core is in the Arctic Circle north of Alaska, we won't get anything from it until 12z Thu(6a Thu) and this will only be the periphery of the jet at CYEV and CYVQ over NW Canada. The second will be taking a similar treck as the first. Both of these will get sampled close to their cores with the 12z Fri(6a Fri) releases from CYYE and CWSE and if those are successful we should see the global suites come somewhat more in line finally. We will stay close to the model runs that had input from these jet max over Japan about 3.5 days ago. The polar and subtropical jets will phase Fri morning as the polar trough opens up from the first pulse, the second stronger pulse causes the trough to combine and slow the coupled trough down as it causes the trough to dig then start lifting out as these faster winds exit to the east side of the immediate trough Sunday. For these reasons, the slower deeper solution of the GFS and CMC would be selected over the Euro. The cold air rush will continue coming even as the precip moves out. This is when Cold Weather Advisories and other cold products and headlines will be posted since the main headline and focus needs to be the Winter Storm Watch at the moment.

SHORT TERM

(Tonight through Friday night) Issued at 1148 PM CST Wed Jan 21 2026

A swath of mostly light rain continues to track ENE along the northern Gulf Coast including the local forecast area early this morning. A very expansive upper level trough encompasses almost the entire US. The nearest shortwave trough axis to the north of the region is already pulling north. Thus, frontal boundary associated with that system has stalled in the vicinity of the CWA and is gradually dissipating. That slow weakening will allow for lingering showers in the morning hours today but will covering lessening with time. At the same time, should be relative cloudy throughout the day with mild temps as zonal flow aloft temporarily sets up. Similar conditions expected on Friday in terms of temps and POPs.

LONG TERM

(Saturday night through Wednesday night) Issued at 1148 PM CST Wed Jan 21 2026

The biggest impact to the forecast period begins to take shape over the weekend. The large scale pattern that appears to be occuring is a potent shortwave trough embedded in the large scale trough diving south to the Gulf Coast. At the same time, a southern stream upper low coming from the Pacific across the Baja of California and merges with that shortwave Sunday. This convergence of these features takes place right over the local region. So what you get is abundant moisture and warmth in the mid levels with arctic cold undercutting it as it surges south. When you look at model soundings Sunday, its hard to remember an event in recent times where temps at the surface were near/below freezing while 850mb was nearly 20 degrees F warmer! That type of profile completely supports freezing rain...with the caveat that sleet not impossible in far NWRN areas of the CWA where cold layer could possibly be a little deeper. So how much ice accumulates and how far south do accumulations reach into the CWA. That's the million dollar question and 5 days out science isn't going to be providing high precision. However, still can have a somewhat decent idea and latest forecast follows that with highest probability of any ice along/NW of a line from KBTR to KMCB...and that's generally what previous forecast indicated for Sunday afternoon into the early overnight hours.

Impacts don't end with the ice potential as 1035-1040mb ridge builds in and really drives in the cold air. There will be multiple nights going into next week where hard freeze conditions occur. Some locations in far northern CWA parishes/counties may be near freezing or below for 30-40 hours.

Will we see temps rebound back to normal this forecast period? Probably not. Realistically likely looking at the following weekend before low/mid 60s highs return.

AVIATION

(12Z TAFS) Issued at 519 AM CST Thu Jan 22 2026

Cigs will be lowest over the northern third of the area with BTR and MCB having IFR while ASD and GPT stay in MVFR to VFR and all others VFR today. Some -SHRA will limit vis to 3 to 5SM including some BR in and out this morning causing vis to also produce MVFR to IFR levels temporarily. A few sites could have FG with 1/2SM but this should be fleeting. This changes this evening and overnight as all terminals will fall to IFR or lower levels due to cigs and a few with vis issues as well nearest the coast.

MARINE

Issued at 1148 PM CST Wed Jan 21 2026

A cold front slowly moving southeastward through LA and MS will be washing out before it reaches the Gulf due to upper level trough situated to the north is already moving to the east and farther away from the local area. Weakening front means the surface pressure gradient is already relaxing. Winds in the tidal lakes have started relaxing on a open Gulf waters will be doing the same as well.

The rest of this week into the weekend, there will be a gradual transition to persistent easterly winds of 10 to 15 knots as zonal flow develops before next trough comes through. A low pressure system is expected to pass through the waters Saturday into Saturday night. The easterly winds will turn more southeasterly and increase to 15 to 20 knots as this low tracks through the waters. In the wake of the low, a strong cold front will sweep across all of the coastal waters on Sunday. Winds will shift to the northwest and quickly ramp up to 20 to 25 knots by Sunday afternoon. These small craft advisory conditions will persist into Monday.

LIX WATCHES/WARNINGS/ADVISORIES

LA...Winter Storm Watch from late Saturday night through Sunday afternoon for LAZ034>037-039-046>048-071-083.

GM...Dense Fog Advisory until 11 AM CST this morning for GMZ530-532- 534-536-538-552-555.

MS...Winter Storm Watch from late Saturday night through Sunday afternoon for MSZ068>071.

GM...Dense Fog Advisory until 11 AM CST this morning for GMZ532-534- 536-538-552-555.