textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 531 AM CDT Thu Sep 17 2026

- A weak cold front will bring drier air into the area today and Friday resulting in more comfortable humidity levels.

- Rain chances will gradually increase going into the upcoming weekend and early next week.

SHORT TERM

(Now through Sunday) Issued at 147 AM CDT Thu Sep 17 2026

The robust H5 ridge will remain over the Midsouth today allowing for a dry northeasterly flow aloft to take shape over the region. This will promote much lower POPs across the region when compared to the last several days. With the 601 dam ridge, temperatures will remain above average across the region. Easterly low level flow will start to gradually decrease along coastal areas today as a surface high continues to drop southward into the "AlaTennGa" region reducing pressure gradient from north to south. Surface dew points will continue to remain on the lower side, so despite the above average temps, heat index values will be a bit more tolerable. This trend will continue into Friday and Saturday. Temperatures going into the weekend will gradually climb higher and close to record territory. Moisture will slowly try to work back into the region, but with strong subsidence and afternoon mixing, it will be a challenge. With that, POPs will remain low until Sunday when there may be just enough low level moisture to have isolated coverage along lake/sea breezes. (Frye)

LONG TERM

(Sunday night through Wednesday) Issued at 147 AM CDT Thu Sep 17 2026

Going into the work week, an upper low will be moving into the eastern Gulf underneath the stronger upper ridging. It still looks like the low will lose the battle against stubborn high pressure to the northwest over the Texarkana region, and the low will eventually dissipate as it move into the central/western Gulf. Models continue to indicate little to no surface reflection of this upper low, and the main impact will be an influx of moisture into the region resulting in a gradual increase in rain chances during the first part of the work week, especially across southern portions of the area.

There continues to be some uncertainty with exactly how far west the low will move before dissipating and thus how much convective activity we'll actually see. The farther west the low moves before dissipating, the better our rain chances will be locally as that would allow for deeper onshore flow. The general trend over the last few model cycles has been for a warmer and drier solution, and the 18z ensemble guidance is coming in similarly as well. That being said, expect to see at least isolated to widely scattered showers and storms each day Mon-Wed, but not expecting any widespread significant rainfall.

Temperatures will remain solidly above normal through the period with lows in the 70s and highs in the low to mid 90s. maximum afternoon heat index values currently forecast generally in the 100- 105 degree range. (DM)

AVIATION

(12Z TAFS) Issued at 531 AM CDT Thu Sep 17 2026

VFR conditions expected through the cycle. Moderate easterly flow will continue for coastal terminals, but likely will see fewer gusts than Wednesday. (Frye)

MARINE

Issued at 147 AM CDT Thu Sep 17 2026

Surface high pressure will wedge down the southern Appalachians through late week. This feature will keep low level pressure gradient somewhat tight and allow easterly winds to remain at or around 20 knots through today. Seas will also remain around 6 to 8 feet in the open Gulf waters. These unsettled marine conditions will gradually abate going into the upcoming weekend. (Frye)

LIX WATCHES/WARNINGS/ADVISORIES

LA...None. GM...Small Craft Advisory until 4 PM CDT this afternoon for GMZ529- 531>536-543-557-577.

Small Craft Advisory until 1 AM CDT Friday for GMZ541-551-553- 554-570-572-575.

MS...None. GM...Small Craft Advisory until 4 PM CDT this afternoon for GMZ531>536-543-557-577.

Small Craft Advisory until 1 AM CDT Friday for GMZ551-553-554- 570-572-575.