textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 635 PM CDT Tue Sep 8 2026

- Scattered to numerous showers and storms are forecast through the forecast period. The overall severe weather threat will be low, but one or two storms could become strong to severe each day.

- Primary threats with storms will be strong wind gusts, frequent lightning and periods of heavy rain leading to localized flash flooding.

- Above normal temperatures expected for most of the 7-Day forecast period. Afternoon heat indices will generally range from 100 to 108 degrees.

SHORT TERM

(Now through Friday night) Issued at 1222 PM CDT Tue Sep 8 2026

Upper ridge extended along Interstate 40 from New Mexico to the Carolinas this morning, with the northern extent of the ridge across the Great Lakes into Ontario. Troughs were off the New England coast and over Montana. An easterly wave was to the south of the ridge over western Louisiana. The surface high pressure was over the Appalachians, and a weak frontal boundary was off the Louisiana coast. This morning's LIX sounding remained very moist with a 2.12 inch precipitable water value, which is right around the 90th percentile. Noon temperatures away from precipitation were in the upper 80s and lower 90s with dew points mainly in the mid 70s.

A weakness in the upper ridge will develop over the lower Mississippi River Valley over the next 48 hours, which is likely to hold the moisture in place over the next several days. While there may not be much organization in convective development, precipitable water values in the upper quartile climatologically will just about guarantee development of thunderstorms each afternoon the remainder of the workweek. As we saw yesterday, a few severe storms can't be entirely ruled out each day. Low level flow will remain easterly through at least Thursday, and any convection that develops should be progressive in that direction. If there's an area that might escape convection on any day, it would be areas north of the Interstate 10/12 corridors tomorrow.

By Thursday night, the break in the ridge becomes more pronounced, and a frontal boundary is expected to move into (but probably not through) the area. This will enhance areal coverage of convection, and increase the threat of heavy rain somewhat, beginning Thursday afternoon and continuing on Friday.

Highs are likely to be in the 90 to 95 range for most of the area this afternoon and tomorrow. As the threat of thunderstorms increases Thursday and Friday, high temperatures are expected to be closer to 90 degrees, and that's probably going to occur late morning or early afternoon. Overnight lows won't change much from day to day. Heat index values should generally remain below the level that would necessitate Heat Advisories (108F).

LONG TERM

(Saturday through Monday night) Issued at 1222 PM CDT Tue Sep 8 2026

The weak troughing over the lower Mississippi River Valley is expected to remain in place Saturday and Sunday before upper ridging builds back eastward, again, early next week.

Saturday and Sunday won't be all day washouts, but outdoor activities should anticipate being interrupted, at a minimum, especially in the afternoon hours. As the ridge builds back in on Monday, It'll be centered near Nashville at that time.

Not much day to day change in temperatures from Saturday for Sunday and Monday with highs around 90, but with less precipitation (and probably fewer clouds), Monday highs should climb a couple degrees, and similar highs probably continue on Tuesday. Would note that if upper ridge would build a bit further south, we could see temperatures warmer than currently forecast, but won't mess with the current trends for now.

AVIATION

(00Z TAFS) Issued at 635 PM CDT Tue Sep 8 2026

VFR conditions are forecast for terminals except if they are impacted directly by any showers and storms. The storms for today seem to be pretty much done outside of a few showers so took out mention for this afternoon. For tomorrow, coverage seems more limited with the best chances being the terminals closer to the Louisiana coast during the afternoon hours. Winds will generally be easterly and light (less than 10 knots).

MARINE

Issued at 1222 PM CDT Tue Sep 8 2026

Will hold onto the Small Craft Exercise Caution headlines for this afternoon, but unsure it'll verify, as we're not seeing observations verifying it right now. Winds should mostly remain between 10 and 15 knots with seas around 2 feet or less through the short term. The primary marine concern will continue to be thunderstorms. Deep moisture remaining over the northern Gulf will favor scattered convection over the coastal waters, particularly during the late night and morning hours before the focus shifts inland with the sea breeze during the afternoon.

Outside of convection, conditions should remain well below advisory criteria. The stronger storms will remain capable of locally gusty winds and briefly higher waves.

LIX WATCHES/WARNINGS/ADVISORIES

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