textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 534 AM CDT Sun Sep 13 2026

- Lower rain chances and warmer temps return first half of the week.

- Stronger easterly winds may result in small craft advisory conditions for the latter half of the week in the coastal waters.

SHORT TERM

(Now through Wednesday) Issued at 1215 AM CDT Sun Sep 13 2026

A broad and deep ridge axis will continue expand eastward from the southern Plains and Texas today and this will lead to both a warmer and drier pattern for the start of the new week. Today and tomorrow will see isolated to widely scattered showers and storms fire up in the mid to late afternoon hours as temperatures climb into the low to mid 90s. A weak remnant outflow boundary just north of the coastal Mississippi and a developing seabreeze will likely collide over this region, and inland areas north of I-10 on the coast will have the greatest rain chances for today. This will also be the area to most likely see a damaging wind gust potential as deeper updrafts experience some dry air entrainment. DCAPE values of 1100 to 1200 J/KG support this higher wind threat for today. As the high continues to strengthen tomorrow, PWATS will continue to fall and overall rain chances will diminish even further. At most, some isolated storms may form in the late afternoon hours along the seabreeze in coastal Louisiana and Mississippi, but these storms will be short-lived and generally weak. Temperatures will continue to run well above average with highs in the low to mid 90s forecast. Fortunately, drier air aloft will mix down to the surface and this will help keep heat index values below advisory levels at around 100 to 105 degrees.

As the high continues to strengthen over Mississippi and Alabama on Tuesday and Wednesday, the pressure gradient over the region will start to increase. Low level easterly winds will increase to 10 to 15 mph by Wednesday and there could be some minor coastal flooding issues on east facing shores, mainly during high tide. PWATS will remain near the average for this time of year and a strong mid-level capping inversion will inhibit most convective development across the area. As seen on Monday, the most likely area for any convective development will be along the coast of Louisiana and Mississippi in vicinity of the seabreeze. The seabreeze will surge further inland on Wednesday on the back of the stronger easterlies, so convection may even make it as far north as metro New Orleans and the River Parishes. Fortunately, any thunderstorm activity will be weak and short-lived due to the strong cap in place aloft. Temperatures will remain well above normal with highs climbing into the mid 90s inland the lower 90s along the coast. No change to heat indices either as dry air continues to mix down with readings peaking between 100 and 105.

LONG TERM

(Wednesday night through Saturday) Issued at 1215 AM CDT Sun Sep 13 2026

By Wednesday night, upper level ridging is expected to be centered (599dm) near Huntsville, Alabama. Meanwhile, an upper trough will be between Bermuda and the Bahamas. This trough will develop a mid level low that moves clockwise around the upper ridge, reaching Florida Friday morning. Beyond that point, the operational GFS/ECMWF solutions diverge greatly. It's been the case the last couple nights that the 12z GFS and ECMWF give the same general forecast trends for next weekend, then the 18z GFS diverges from that solution. The 12z runs eventually take the upper system into the north central Gulf next weekend, while the 18z GFS never brings it west of Florida and then a northern stream shortwave picks it up and lifts it northeast.

This gives quite a bit of confidence to the forecast through at least Friday, and possibly Saturday. Anything beyond that point is beyond the scope of the current forecast package, and model solutions usually do change in one way or another at that time range.

Anything more than very isolated convection over land would be surprising in the Wednesday night through Friday night range. For Saturday (and beyond), will live with the NBM solution for now, while waiting to see which trend holds up with the upper pattern. Temperatures during the day will remain well above normal with highs in the lower and middle 90s. Overnight lows may be a little lower for Wednesday night through Friday night as compared to earlier in the week as drier air is transported into the local area from the north and northeast around the upper ridge. Not out of the question that the normally cooler areas of our CWA could see multiple nights with lows in the 60s. Even if that happens, the numbers in the guidance now would still be several degrees above normal as we approach the autumnal equinox.

AVIATION

(12Z TAFS) Issued at 534 AM CDT Sun Sep 13 2026

No major change in thinking from the previous forecast. VFR conditions and lower thunderstorm chances will continue through tonight. The only terminals with a halfway decent chance of storms firing continue to be GPT and HUM, but probabilities for thunderstorms remain too low to mention in the forecast. Most terminals will only see some scattered clouds form during the day around 3500 feet.

MARINE

Issued at 1215 AM CDT Sun Sep 13 2026

A broad surface high centered over the area will keep benign conditions in place across the waters through Tuesday with light and variable winds of less than 5 knots and seas of less than 2 feet expected. A few showers or storms will pop up in the morning hours with some locally higher winds and waves, but these impacts will be short-lived each day. An increasing pressure difference will develop on Wednesday and continue through the end of the week as a broad low forms south of the waters and the high becomes more centered over Mississippi and Alabama. This will cause winds to increase to at least 20 to 25 knots with gusts near gale force for the latter portion of the week. Seas will respond to these higher winds and increase to 8 to 10 feet from Wednesday onward. Some minor coastal flooding may also impact east facing shorelines over this period.

LIX WATCHES/WARNINGS/ADVISORIES

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