textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 1204 AM CST Fri Jan 23 2026

- A Winter Storm Watch is in effect for southwest Mississippi and a portion of southeast Louisiana for potential of freezing rain this weekend.

- After the threat of freezing rain, the cold Arctic airmass brings coldest air of this winter season with lows in the teens in northern portions of the forecast area to near freezing down to Grand Isle. This is generally Sunday morning through Tuesday morning.

- Cold weather headlines will likely be needed for wind chills in the single digits in southwest MS to mid teens south of I-10.

- Near gale force wind conditions are expected to impact the coastal waters on Sunday and Monday. These strong winds will create hazardous boating conditions in the coastal waters.

SHORT TERM

(Today through Saturday) Issued at 1204 AM CST Fri Jan 23 2026

A broad upper-level trough continues to dominate virtually the entire CONUS, with the local forecast area currently beneath the flatter, more zonal segment of that larger-scale flow. At the surface, a shallow front that pushed into the CWA and stalled yesterday will drift south over time. Model soundings show just how shallow this boundary is. And speaking of those soundings, almost textbook advection fog setup with shallow modest low level inversion underneath 15-20kt southwesterly winds and dry slot aloft. Already seeing fog on interstate cams and some areal obs so went ahead and issued Dense Fog Advisory for this morning. Fairly benign weather for the remainder of the day.

MEFFER

LONG TERM

(Saturday night through Thursday) Issued at 1204 AM CST Fri Jan 23 2026

The high-impact portion of the forecast begins to come into focus over the weekend as a strong shortwave trough embedded within the broader CONUS trough dives toward the Gulf Coast. At the same time, a southern-stream upper low moving east from the Pacific across Baja California approaches and phases with the northern-stream shortwave Sunday. Guidance continues to favor this interaction occurring near the central Gulf Coast.

The resulting setup supports a classic Gulf Coast freezing rain profile: warm, moist mid levels overrunning an increasingly cold, shallow Arctic surface layer that is surging southward...but uncertainly is still relatively high in terms of how far south into the CWA freezing rain reaches.

Before the cold air gets here the environment setup is a bit interesting. A fairly sharp temp and dewpoint gradient will exist across the CWA Saturday with a roughly 30 degree delta-T between Woodville MS and Boothville LA. If you look at soundings along coastal areas from LA to MS, cold air aloft combined with those mid 60 degree temps and you're seeing some elevate instability. Not a lot but non-zero. The more impressive parameters are high shear (not surprising this time if year), moderate helicity and climatologically high PW's. So do have some concern for rotating cells. Surface based?....remains to be seen.

Back to winter wx....the newly combined shortwave and upper low really digs southeastward Sunday. Temps pretty much hold steady all morning then start dropping in the afternoon, followed about 18 hours of falling. Model soundings during this later day period show a very strong warm nose aloftnear 850 mb temperatures roughly 20F warmer than the surface with a saturated column loft. What's different with previous model runs is that they no longer support freezing rain b/c by the time the air cold enough to support this at the surface, the mid and upper levels are already drying out. Not ready to call of the freezing rain potential for one model run.

Regardless of the freezing rain, the arguably bigger hazard for greater % of those in our CWA will be Sunday night through Tues morning. Strong high pressure (10351040 mb) builds in and drives the cold air deeper into the region. Multiple nights of hard freeze conditions appear likely next week, and parts of the far northern parishes/counties could remain near or below freezing for **3040 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. Plus, wind chill values, especially Monday morn, will be possibly as cold as 0 <---that's the # Z E R O in southwest MS and even in the 10-15 degree range down to the LA and MS coastlines.

Will we see temps rebound after Tuesday? Probably not. Realistically likely looking at continued cold though not bitterly cold the rest of next week.

MEFFER

AVIATION

(06Z TAFS) Issued at 1204 AM CST Fri Jan 23 2026

IFR to LIFR conditions are ongoing at all terminals right now due to low ceilings and visibilities. Fog, dense at times, will likely hang around at most terminals through the morning hours. The fog will then lift. Ceilings will slightly lift as well but still will be relatively low so terminals will eventually reach MVFR during the daytime hours.

MARINE

Issued at 1204 AM CST Fri Jan 23 2026

Model sounding profiles suggest that conditions remain favorable for another round of dense sea fog to develop over the nearshore waters and lakes this morning. A marine dense fog advisory will be in effect for that threat.

Stalled and weak front from yesterday will be reinforced as more of a backdoor front today. That'll will shift winds to the east and east-northeast and begin to strengthen them. Wind speeds will also increase to 15 to 20 knots as the surface pressure gradient tightens resulting in some exercise caution conditions. A low pressure system will approach on Saturday, and this will cause winds to shift back to the south and increase further into small craft advisory range. As the low pulls away Sunday afternoon, a strong cold front will push through. Winds will shift to the northwest and north and wind speeds could further increase to near gale force Sunday night into Monday. As high pressure builds in Monday night into Tuesday, the northerly winds will gradually decrease, but small craft advisory conditions will persist.

MEFFER

LIX WATCHES/WARNINGS/ADVISORIES

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

Dense Fog Advisory until 8 AM CST this morning for LAZ036-037- 039-046>048-056>060-064>071-076>090.

GM...Dense Fog Advisory until 9 AM CST this morning for GMZ530-532- 534-536-538-550-552-555-557.

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

Dense Fog Advisory until 8 AM CST this morning for MSZ070-071- 077-083>088.

GM...Dense Fog Advisory until 9 AM CST this morning for GMZ532-534- 536-538-550-552-555-557.