textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 653 PM CST Mon Nov 17 2025

- Areas of dense fog possible during the early morning hours on Tuesday, Wednesday, and Thursday. - Above normal temperatures expected through Saturday.

- A cold front will bring higher rain chances to the area on Friday.

- Hazardous marine conditions due to stronger southerly winds on Thursday and Friday.

UPDATE

Issued at 653 PM CST Mon Nov 17 2025

Checking the potential for dense fog and at this time we will continue to hold off on a dense fog adv. Not saying we won't dense fog tonight but it doesn't seem as probable tonight. First concern is the cirrus cover but that shouldn't be an issue as the clearing line is already a 3rd of the way through the area. The biggest difference it looks like we may not cool enough. With this still being a radiational fog setup/concern one key to look at will be the cross-over temp which is around 60-62. So we probably need to at least cool to 61 to have a real shot of areas to widespread dense fog and realistically probably need to get down into the upper 50s to get decent coverage of dense fog. That said by no means are we saying will fog not develop and not saying dense fog will not develop and to be honest it will likely develop in patches/isolated areas and most likely locations could be the Pearl River drainage area and west across the Florida parishes and along the MS/AL border. We will continue to look over it closely and get an advisory out quickly and hopefully before the evening news cycle. /CAB/

SHORT TERM

(Tonight through Wednesday night) Issued at 653 PM CST Mon Nov 17 2025

Very little change in the day to day weather conditions are expected through the short term period as a broad deep layer ridge axis continues to dominate the Gulf South. Temperatures will remain well above average with readings running around 10 degrees above normal through Wednesday night. The deep layer ridging will keep a strong mid-level capping inversion in place, and this will prohibit any rainfall from forming. However, there will continue to be a persistent light onshore flow regime that will allow for high humidity values in the low levels. As a result, some scattered strato-cumulus development can be expected each day. This strato-cumulus will form as an extensive morning fog bank mixes out with daytime heating each morning.

In terms of the fog threat, conditions are extremely favorable for widespread fog to form across much of the area in the early morning hours tonight, tomorrow night, and Wednesday night. Fog probabilities remain very high through the period and confidence is also high that more fog will form. These conditions include, the upper level ridge over the region, strong radiational cooling, light winds, and the high low level humidity. The fog will turn dense at times, and a dense fog advisory will likely be needed again for tomorrow morning over portions of the area. Any burning of agricultural fields could produce very isolated areas of superfog and near zero visibility each morning as well.

LONG TERM

(Thursday through Sunday night) Issued at 653 PM CST Mon Nov 17 2025

The long term model guidance is in remarkably good agreement and overall ensemble spread is on the lower end as move into the latter part of the workweek and upcoming weekend. This lends higher confidence to the overall forecast. Thursday will be a day of transition with stronger winds developing as the pressure gradient over the area increases in response to a low pressure system deepening over the Southern Plains. Southerly winds should increase to 10 to 15 mph by the afternoon hours. Temperatures will also remain well above average on Thursday with readings easily rising into the lower 80s. By Thursday night, there are indications that weak region of increased upper level forcing will form beneath an increasingly difluent flow pattern aloft. Additionally, a plume of deeper moisture will feed into the region with PWATS rising to around the 90th percentile. With favorable forcing parameters in place, some scattered shower activity should form Thursday night over the area. Fortunately, despite the high PWATS, a heavy rainfall signal is not in place due to a lack of decent thermodynamic support. Any showers will be light and transient in nature through the overnight hours.

Friday will be the primary rain day as the shortwave energy in the Southern Plains passes through the Mid-Mississippi Valley. A trailing trough axis will slide through the area and serve as a focusing mechanism for showers and a few weak and low topped thunderstorms throughout the day on Friday. PWATS will remain in the 90th percentile range for this time of year, so a few brief heavy downpours could occur with any of these weaker storms that form. However, the lack of sustained updraft development due to the limited instability will limit heavy rain potential with most areas seeing less than an inch of rainfall from the event on Friday. Temperatures will remain above average with highs once again climbing into the upper 70s and lower 80s as winds remain from the south.

Well behind the main trough axis and overall rain event, the trailing cold front will finally push through Friday night. A few showers and storms could fire up along the front itself, but the lack of instability will greatly limit overall convective development. At the same time, some weak cold air advection will take hold behind the front. Lows will remain very mild Friday night, but daytime highs will be around 5 degrees cooler on Saturday. These values will still be above average, but not quite as extreme as the temperatures experienced the past several days. Additionally, a surge of drier air aloft will feed into the region and PWATS will fall back to the normal levels seen for this time of year. Further drying in the mid and upper levels is expected by Sunday as an upper level ridge axis begins to build in from the west. PWATS will fall to around the 25th percentile and this will allow for mainly clear skies and dry conditions as we close out the weekend. Temperatures will also continue to cool as the northwest flow regime aloft ushers in somewhat cooler air. Temperatures will fall to more normal readings for mid to late November with highs in the lower 70s and lows in the upper 40s and 50s. Overall, a fairly pleasant weekend is anticipated once the front clears the region.

AVIATION

(00Z TAFS) Issued at 653 PM CST Mon Nov 17 2025

Still concerned with dense fog tonight. Conditions still remain favorable for fog and low stratus to form at all of the terminals but not too confident it will be dense. There was a good deck of cirrus overhead but that is clearing and at least a 3rd of the area has already cleared out. Fog developed rather quick last night but may take a little longer tonight. Expect some terminals to start showing reduction in vsbys around 5/6z and then expand across the area and likely get worse for terminals on the northern half of the CWA. South may be more of a low cloud issue but even some vsby restriction will occur. Conditions will start to slowly improve after 14z but by 15z most if not all terminals will at least be in MVFR status if not VFR. /CAB/

MARINE

Issued at 653 PM CST Mon Nov 17 2025

Through Wednesday, a prevailing light southeast flow of less than 10 knots and seas of less than 2 feet can be expected as the region remains on the western periphery of a broad surface high pressure system. By Thursday, the pressure gradient over the Gulf waters will begin to increase as a low pressure system deepens over Texas. This low will pass to the north of the area on Friday and push a weak cold front through the waters. Stronger southerly winds of at least 15 to 20 knots and potentially up to 25 knots will impact the open Gulf waters as this system moves through. Seas will also rise to 5 to 7 feet in response to the stronger winds. Fortunately, a strong surge of colder air will not accompany the front, so winds will weaken back below 15 knots as they shift to the west and northwest on Saturday.

PRELIMINARY POINT TEMPS/POPS

MCB 60 81 60 82 / 0 0 0 0 BTR 62 83 61 83 / 0 0 0 0 ASD 59 79 58 80 / 0 0 0 0 MSY 64 80 63 80 / 0 0 0 0 GPT 62 75 61 77 / 0 0 0 0 PQL 58 77 58 78 / 0 0 0 0

LIX WATCHES/WARNINGS/ADVISORIES

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