textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 140 AM CDT Wed Sep 16 2026

- Drier air from a back door front brings breezy conditions along coastal areas, unsettled marine waters, and a few scattered showers/storms today.

- More comfortable humidity and dry conditions will follow on Thursday and Friday, but moisture and rain chances will begin to return by the weekend.

SHORT TERM

(Now through Saturday) Issued at 140 AM CDT Wed Sep 16 2026

A weak/subtle backdoor front is moving into the region from the east. High pressure is wedging down the lower appalachians, which will be responsible for decreasing surface moisture beyond today. Pressure gradient will also begin to increase with some coastal gusts approaching 20 to 25 mph during the afternoon. Additionally, convection, although somewhat limited in coverage will be possible, especially over the MS Gulf Coast as well as southeast Louisiana mainly south of the I10 corridor. CAMs show some rather decent parameters. First, instability will be there generally at or above 3K-JKg. DCAPE values of 1200 JKg is also expected during the afternoon, so wider and more robust updrafts will have the potential for a strong wind gust or two. PWAT values of 2.2" will allow for efficient rainfall rates, but with the mean level flow allowing for storm movement (generally east to west), outside of the typical urbanized areas, localized flash flooding will be limited.

Going into Thursday and beyond, the primary story will be lower RH values, which despite the lower to middle 90s expected for high temps (nearing record territory), heat index values will not be much higher as dew point values drop into the lower to mid 60s during the afternoon hours. Otherwise, moderate easterly flow will continue as moderate pressure gradient remains in place between the high wedging down the Appalachians and the lower pressure in the southern Bay of Campeche. (Frye)

LONG TERM

(Saturday night through Tuesday) Issued at 140 AM CDT Wed Sep 16 2026

While the daytime Tuesday medium range modeling agrees on the upper ridge being near Texarkana Saturday evening, and remaining over Arkansas for most of the long term period, they definitely do not agree on the upper low moving across Florida into the Gulf. The ECMWF side doesn't bring the upper circulation much further west than the west coast of Florida near Tampa by Saturday evening, the GFS operational has it off of Southwest Pass. The ECMWF solution sits it near Tampa for a couple days before weakening it and taking it northward near Tallahassee on Tuesday. In the 15/18z GFS operational solution, the low eventually makes it the entire way across the Gulf to Texas by the middle of next week. In a spread like this (west vs north), there's really no happy compromise solution regarding the upper feature, and WPC also notes the uncertainty. There's not much in the way of a surface reflection in the pressure fields in either family.

On the brighter side locally, neither family of solutions track real deep moisture across the area until perhaps midweek next week, if even then. Until then, precipitable water values look to remain generally in the 50th to 75th percentile climatologically (in the 1.6 to 1.8 range). The upper high appears to remain close enough to our area to keep precipitation development on the scattered side and primarily during the afternoons.

Even with different scenarios, in this case, the deterministic forecast ends up being fairly similar. Temperatures a bit above normal (90-95F) and scattered PoPs each day, primarily in the afternoon. (RW)

AVIATION

(06Z TAFS) Issued at 1221 AM CDT Wed Sep 16 2026

Mostly VFR conditions expected through the overnight and into the morning hours on Wednesday. There will be some limited convective development during the day on Wednesday, but low confidence is keeping most sites dry. Closer to the coast the surface winds are forecast to increase during the day with some gusts for HUM, GPT, NEW, and MSY approaching 25 to 30 knots at times. Winds should decrease just a bit shortly after sunset and become far less gusty. (Frye)

MARINE

Issued at 140 AM CDT Wed Sep 16 2026

Surface high pressure will wedge down the southern Appalachians through mid to late week. This feature will increase low level pressure gradient and allow surface winds to increase to SCA thresholds today and Thursday. Seas will respond to these higher winds and increase to 6 to 9 feet in the open Gulf waters. These unsettled marine conditions will gradually abate late Friday and into Saturday. A few showers or storms may develop during the morning hours with some locally higher winds and waves possible, especially this morning. (Frye)

LIX WATCHES/WARNINGS/ADVISORIES

LA...None. GM...Small Craft Advisory from 7 AM this morning to 4 PM CDT Thursday for GMZ529-531>536-541-543-551-553-554-557-570-572-575-577.

MS...None. GM...Small Craft Advisory from 7 AM this morning to 4 PM CDT Thursday for GMZ531>536-541-543-551-553-554-557-570-572-575-577.