textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 439 AM CST Wed Jan 7 2026

- 1st concern continues to be fog potential through Thursday. Patchy dense fog is expected for much of the area late tonight and again Wednesday night into Thursday morning. Plan ahead for possible travel delays due to low visibility during the morning commute hours.

- Next concern is the risk of strong to severe storms mainly Friday night as the next potent storms system works across the central US and a cold front moves across the area. SPC currently has a 15% probability of severe weather across northwestern portions of the CWA.

- Last topic is highs the next few days. We will be quite warm with a few locations likely topping out around 80 and this could test some records with the best chance of breaking a few on Thursday.

SHORT TERM

(Tonight through Friday night) Issued at 1020 PM CST Tue Jan 6 2026

Very little change in the forecast from the previous packages as all of the guidance remains in good agreement through Friday night. Through Wednesday night, the pattern that we have seen over the region will be little changed with a strong mid and upper level westerly flow regime remaining in place. In the low levels, a broad surface high centered over Florida will keep a light southwest flow pattern off the Gulf in place. Temperatures and dewpoints within this low level flow pattern will remain extremely warm with highs easily climbing into the upper 70s and lower 80s over most of the region both Wednesday and Thursday afternoons. Only areas along the immediate coast will be slightly cooler, but still well above average, in the mid 70s. These readings will be very near or even exceed the record highs for the region. Temperatures will cool to the dewpoints in the lower 60s each night, and conditions look favorable for some fog development to occur each night. Tonight, any fog that forms will develop closer to sunrise and dense fog should be very patchy due to less favorable winds and the passage of some high level cloud cover across the region. However, conditions look more favorable for widespread dense fog to develop Wednesday night into Thursday morning as winds turn more from the due south at 5 to 10 mph. Fog would be most likely to occur along and north of the I-10 corridor where temperatures are forecast to cool the most.

The switch to a more southerly and southwesterly wind field will be in response to a fast moving shortwave trough and associated deepening surface low over the southern Plains that will pass well north of the region Thursday afternoon into Thursday night. Although we are not expecting any direct impacts from this system, the increased deep layer southerly flow will allow for a much deeper pool of Gulf moisture to feed into the region, and this will push PWAT values up to the daily maximum of around 1.7 inches by Friday morning. As moisture deepens, the mid-levels will begin to cool slightly resulting in gradually steepening mid-level lapse rates and greater overall instability. A broad region of increased moisture pooling along the stationary front left behind by the initial trough late Thursday night into Friday morning will combine with the favorable jet dynamics in place to produce scattered to numerous showers, but instability will still be insufficient enough to induce any deeper convective activity. Temperatures will extremely warm as dewpoints surge into the mid to upper 60s.

As we move into Friday afternoon and evening, conditions become far more favorable for some strong to severe thunderstorm activity to impact a portion of the forecast area. A strong southern stream trough kicking out of the southern Rockies will start to merge with northern stream energy descending down from the northern Plains to form a rapidly deepening positively tilted longwave trough axis across the Plains states. As this occurs, a potent low level jet will form across the Lower Mississippi Valley in advance of deepening surface low over the Arklatex region. As noted above, the atmosphere will be extremely moisture laden and lapse rates in the mid-levels will continue to steepen as this longwave trough approaches from the west. By the mid to late afternoon hours, these lapse rates should approach 6.5C/km. Those values indicate a fair degree of instability and that is confirmed by model output MLCAPE approaching 1000 J/KG in the mid to late afternoon hours over southwest Mississippi and metro Baton Rouge. These values will support the development of deeper and longer lasting updrafts. In addition to the thermodynamic support, the development of a 40 knot low level jet over the region in the afternoon will further support the severe weather threat. As this low level jet strengthens, effective bulk shear values of 50 knots will develop across the north and northwest portions of the forecast area. Additionally, storm relative helicity values should peak around 200 m2/s2 in the late afternoon and early evening hours over these areas, primarily southwest Mississippi and points west of I-59 and north of I-10 in southeast Louisiana. Given these parameters, I am still concerned that we will see a QLCS type of severe weather threat that has ability to produce brief tornadoes and straight line wind damage as it moves through the area late Friday afternoon into early Friday evening.

Later Friday night, the severe threat will start to diminish as the low level jet weakens and the cold front itself begins to move through. However, some stronger storms embedded with in a more typical linear convective feature could bring brief gusty winds to portions of the Mississippi coast during the overnight hours. Areas further to the south have a much lower risk of strong to severe storms as the low level jet dynamics are simply less favorable through the entire event.

LONG TERM

(Saturday through Tuesday night) Issued at 1020 PM CST Tue Jan 6 2026

As the front pushes offshore during the day on Saturday, the positive tilt of the broader upper level trough axis will keep a southwest flow pattern in place in the mid and upper levels. With the low levels cooling off a good 10 degrees on Saturday, some post-frontal isentropically induced cloud cover and light rain activity will persist through the day on Saturday. Conditions will finally start to clear and dry by late Saturday night as the wind field aloft turns more northwesterly and a much colder and drier airmass finally moves in from the northwest. A decent 925mb thermal trough axis will be over the region with readings of around 3C supporting highs in the mid to upper 50s on Sunday, Monday, and Tuesday. Conditions will be dry and stable through the start of next week as a mid-level ridge slides through the area. With mainly clear skies and drier air in place, overnight lows will easily cool into the 30s north and west of Lake Pontchartrain for Sunday, Monday, and Tuesday nights. South of the lake and along the coast, lows will dip into the lower 40s each night.

AVIATION

(12Z TAFS) Issued at 500 AM CST Wed Jan 7 2026

IFR/MVFR VIS/CIGs are ongoing across most terminals this morning. Like the last day or two conditions will improve through the morning and into the afternoon hours. VFR conditions are expected through the afternoon and evening hours. However, more VIS/CIG reductions are expected late in the cycle with a better signal for fog Thursday morning. Winds will transition to a more southerly direction through the day, but overall should remain on the light side (generally less than 10kt). (Frye)

MARINE

Issued at 1020 PM CST Tue Jan 6 2026

A threat of some fog forming over the waters will exist Wednesday night into Thursday, but dewpoints are rising so high into the low to mid 60s that dense fog appears to be less of a concern. By Thursday night, onshore flow will start to increase as a low pressure system deepens over the Southern Plains. Winds will rise to 15 to 20 knots by Friday and seas will start to turn choppy at 3 to 6 feet by Friday afternoon. A cold front trailing the low pressure will move through the waters on Saturday, and winds will shift to the northwest and increase into small craft advisory range of 20 to 30 knots as a cooler and drier airmass moves in from the north. These elevated winds and hazardous seas of 7 to 10 feet will persist into Monday morning before beginning to ease as a high pressure system becomes more centered over the waters.

PRELIMINARY POINT TEMPS/POPS

MCB 78 60 79 64 / 0 0 10 60 BTR 80 62 81 67 / 0 0 10 60 ASD 78 60 78 63 / 0 0 10 40 MSY 78 63 79 66 / 0 0 10 40 GPT 73 61 72 64 / 0 0 10 30 PQL 75 61 75 64 / 0 0 20 20

LIX WATCHES/WARNINGS/ADVISORIES

LA...Dense Fog Advisory until 10 AM CST this morning for LAZ034>037- 039-046>048-056>060-064>071-076>090.

GM...Dense Fog Advisory until noon CST today for GMZ530-532-534-536- 538-550-552-555-557.

MS...Dense Fog Advisory until 10 AM CST this morning for MSZ068>071- 077-083-086>088.

GM...Dense Fog Advisory until noon CST today for GMZ532-534-536-538- 550-552-555-557.