textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 1213 PM CST Wed Jan 21 2026

- A potentially significant freezing rain event is becoming more likely over the northern tier of the forecast area. Rain will move in on Saturday, but the rain will transition to freezing rain Saturday across portions of southwest Mississippi and the adjacent Florida Parishes. There currently is a 40-60% chance of accumulating ice in those areas Saturday night, with 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 driving the winter precipitation will linger across the area with lows in the upper teens to low 20s along and north of I-12 Sunday morning through Tuesday morning. With that being said, cold weather headlines will likely be needed as early as Sunday morning, with Monday and Tuesday mornings being the coldest at this time.

SHORT TERM

(This evening through Friday night) Issued at 1213 PM CST Wed Jan 21 2026

No significant changes from the previous forecast overall through Friday night. The Gulf South region will remain embedded beneath a zonal flow pattern in the mid and upper levels. At the same time, a persistent onshore flow regime will be in place in the low levels. This onshore flow pattern will continue to advect in a warm and humid airmass, and this will keep temperatures well above average through Friday. Highs will climb into the upper 60s and lower 70s each day, and overnight lows will only dip into the low to mid 50s. Late Friday night, a backdoor cold front will begin to move into the area, and this will help to lower temperatures slightly for areas north of I-10 with readings falling into the 40s.

A fast moving shortwave trough and associated 120 knot jet streak will pass through the Lower Mississippi Valley this afternoon into tonight. The system will start to shift to the east by tomorrow morning. Favorable upper level dynamics from the region being in the entrance region of the jet streak and the increasing positive vorticity advection associated with the passing trough will produce ample forcing in the mid and upper levels. This forcing will tap into the moderately unstable and very moist environment to produce periods of light rainfall through the overnight hours. As the trough axis departs tomorrow morning, increasing negative vorticity advection and upper level subsidence will begin to take hold. This will help to suppress rain chances through Thursday night with only some low topped and very isolated shower activity anticipated.

Friday will see a bit higher rain chance as another weak area of enhanced vorticity slips through, but the activity will remain light and very scattered due to the lack of any low level forcing mechanisms nearby and a continued strong mid-level capping inversion. However, as we move into late Friday night, rain chances will start to increase across the northern third of the CWA as the backdoor cold front starts to push in. Increasing isentropic forcing over a shallow cold pool will support a region of light stratiform rain formation by daybreak on Saturday across southwest Mississippi and portions of the Florida Parishes.

LONG TERM

(Saturday through Tuesday night) Issued at 1213 PM CST Wed Jan 21 2026

The medium range guidance has started to come into better agreement today with smaller temporal and spatial model spread and less temperature spread between the 25th and 75th percentiles in the NBM. That being said, the forecast is still highly dependent on exactly how far south the freezing temperature line can get Saturday night into Sunday morning, and there will be a very sharp thermal gradient across the forecast area as the initial backdoor cold front stalls out. A broad region of isentropically induced rainfall will persist into Saturday across the area as temperatures remain above freezing. However, by Saturday evening, temperatures will start to cool below freezing in southwest Mississippi, and the freeze line will then gradually dip southward toward northern portions of metro Baton Rouge by Sunday morning. The isentropically induced rainfall will turn a bit more heavier Saturday night as another jet streak and increasingly difluent flow aloft increases overall omega values in the region.

The one thing of note is that overall probabilities of freezing rain accumulation have stayed steady today in the NBM with the chance of ice accumulation remaining between 40 and 60 percent for locations in southwest Mississippi and the Felicianas. This continues to be the most likely area to see ice accumulation occur, and the forecast has changed little from before in terms of the freezing rain location. Further to the south, temperatures are projected to remain above freezing, so it will be a rain event for the Northshore, Southshore, and coasts of Louisiana and Mississippi this weekend. One other thing we are starting to be a bit concerned about is the potential for strong to severe thunderstorms impacting areas along the immediate coast of Louisiana and the offshore waters where surface based instability and very strong directional shear parameters could be in place. This will be highly dependent on the exact track of a surface based low pressure system that is projected to move through the area on Saturday.

Conditions will quickly dry out on Sunday as a surge of drier air and strong negative vorticity advection in the wake of a passing strong longwave trough overspreads the Gulf South. Lingering precipitation is expected in the morning hours, but conditions will quickly dry out from west to east in the afternoon hours, and expect to see dry conditions at all locations over land by the evening hours. Along with the increasing dry air advection, an extremely cold arctic airmass will begin to feed into the region. Highs will peak in the morning hours with temperatures falling in the afternoon hours as the arctic air moves in. This will keep highs in the 30s over the northwest third of the CWA and the 40s and lower 50s along the coast. Extremely cold conditions will then be in place from Sunday night through Tuesday night and extreme cold headlines will be in place during this period of time. Lows will fall into the teens north of I-12 and the mid 20s further south. Winds will remain gusty, so wind chills will dip into the single digits and teens. Highs will only climb into the upper 30s and lower 40s Monday afternoon, and temperatures will plunge back into the teens and 20s Monday night. Some modification in the airmass will take place on Tuesday as the heart of the arctic airmass starts to shift away, but temperatures will still be a good 15 to 20 degrees below average with readings in the 40s during the day and the 20s Tuesday night.

AVIATION

(18Z TAFS) Issued at 1213 PM CST Wed Jan 21 2026

Periods of light rain could briefly reduce visibilities to MVFR range of 4 to 5 miles this afternoon, especially at BTR and MCB where PROB30 groups indicate this threat. After 00z, the light rain will spread to the remainder of the terminals and produce similar MVFR impacts. However, between 06z and 08z, as temperatures cool, a low stratus deck will rapidly develop at all of the terminals with prevailing IFR conditions. Ceilings will generally range from 300 to 600 feet. Visibilities will also reduce as this stratus builds down with visibilities of 2 to 3 miles at most locations. The low stratus will persist into the morning hours tomorrow.

MARINE

Issued at 1213 PM CST Wed Jan 21 2026

Persistent east winds of 10 to 15 knots will remain in place through Friday night. 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 or exercise caution range 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...None. GM...None. MS...None. GM...None.