textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 600 AM CDT Thu Sep 10 2026

- Another surge of tropical moisture will elevate the risk for locally heavy rainfall leading to street flooding and overflowing of poor drainage areas Thursday through Sunday.

SHORT TERM

(Now through Sunday) Issued at 1232 AM CDT Thu Sep 10 2026

A more unsettled weather pattern will take hold of the region today and continue through the weekend. This pattern will be driven by the development a broad, but fairly weak, mid to upper level trough axis across the Lower Mississippi Valley and Gulf South today and into tomorrow. The trough will linger over the area through the weekend before shifting out of the area early next week. Weak forcing aloft will combine with ample moisture as noted by PWATS ranging from the 90th percentile to the daily max for this time of year, or well over 2 inches, and sufficient instability to produce multiple rounds of showers and thunderstorms through the weekend. Given the warm airmass aloft and deep tropical moisture in place, efficient rainfall processes will support higher rainfall rates of 2 to 4 inches per hour with any stronger storms that form. Storm motions will average 5 knots today, and this will lead to increased flooding risk, especially in low lying and poorly drained areas. Thus, a level 1 out of 5, or marginal risk, of flooding rainfall is in place for today across most of the region. On Friday and Saturday, storm motion will increase slightly to around 10 knots, but localized flooding will still be a concern if any training of storms over the same region occurs. Although PWATS will begin to decline slightly on Sunday, storm motion will also drop back to around 5 knots and localized flooding will remain a risk. Model soundings are not supportive of any severe storms developing due to a lack of sufficient shear and the warm air aloft limiting hail development. Temperatures will also be near or even slightly below average through the weekend with highs in the upper 80s and lower 90s and heat index values peaking out near 105.

LONG TERM

(Sunday night through Wednesday) Issued at 1232 AM CDT Thu Sep 10 2026

By Monday, upper level high pressure has moved into the area from the east and taken a firm hold over the southern US. This will bring us back to the summer pattern of afternoon temperatures in the low to mid 90s and 30-50% PoPs in the afternoons. These highs temps are about 5 degrees above normal for the end of summer and combined with the humidity will put heat index values in the 105-110 range, so at this point in time I have to mention the possibility of heat headlines. The good news about the rain is it helps put a bit of a damper on the temperature rise

AVIATION

(12Z TAFS) Issued at 600 AM CDT Thu Sep 10 2026

The pattern will be quite stormy with multiple rounds of showers and thunderstorms impacting the terminals. Coastal terminals like GPT, HUM, MSY, and NEW will be the most impacted by these repeated rounds of showers and storms and PROB30 or TEMPO wording is in place through 00-02z, or the majority of the forecast period to reflect this risk. Further inland, at MCB, ASD, HDC, and BTR, the thunderstorm activity will be a bit delayed and will run from 14-16z through 00z. It is difficult to time out the exact period that storms will impact the terminals as there is no large scale system to hone in on for development, thus the extended window of convective impacts using PROB30 wording. MVFR and IFR visibility restrictions of 2 to 5 miles, gusty winds of 25 to 35 mph, and lightning strikes can be expected as these storms move through.

MARINE

Issued at 1232 AM CDT Thu Sep 10 2026

A weak area of low pressure will move through the waters today with light and variable winds of less than 10 knots expected. As the low shifts to the west tomorrow, winds will turn more south- southwesterly at 10 to 15 knots. These conditions will persist into Saturday. High pressure centered over the eastern Gulf and southeastern United States will become more dominant as we move into next week, and this will cause winds to turn more south- southeasterly at 5 to 10 knots from Sunday onward. Seas will generally remain in the 1 to 3 feet range with the highest seas well offshore. Additionally, thunderstorm activity will develop each day, peaking in the early to mid-morning hours, and these storms will produce higher wind gusts, waterspouts, and lightning concerns.

LIX WATCHES/WARNINGS/ADVISORIES

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