textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 105 PM CDT Wed May 20 2026

- Expect high rain chances through the next several days. 7 day rainfall totals will range from 4 to 7 inches in the northwest to less than an inch of much of coastal MS and extreme SELA.

- Minor coastal flooding may slightly impact typically known problem areas like Waveland, MS today around midday.

SHORT TERM

(Now through Saturday night) Issued at 105 PM CDT Wed May 20 2026

The upper level pattern shows a cutoff low east of Florida, a weak ridge centered near the Bay of Campeche and finally more broad scale trough over much of the rest of the country northwest of a line from El Paso to Chicago. Established onshore flow will continue to bring moisture into the column. The 12Z KLIX sounding had a 1.6" PW and by this afternoon we'll be looking at 2"+ across the CWA. From a climo perspective, that's well above the 90th percentile which is 1.75" and much closer to daily max or record. Important to remember that high PW, even daily record, does not always equate to flash flooding but certainly presents potential. Upshear/downshear corfidi vectors aren't prime this morning but do look more concerning later today as upshear drops to nearly 5kts. At that same time, downshear of 15+kts suggest storms still move a decent clip. Nearly same direction corfidi directions, however, definitely doesn't scream watch out Other factors related flash flood risk today include warm sfc temps with highs in the mid 80s and then slow moving or stalling front in central LA. Model soundings show really decent cooling in the mid/upper levels which yields quite impressive instability. Finally, add in that stalling cold front in central LA will be sagging south today. So overall threat appears to fall right in line with WPC's Slight Risk of flash flooding today. Development along outflow boundaries or cell interactions with them will need to be monitored closely.

Warm and humid conditions in place along with cloudy skies should continue to limit overnight cooling quite significantly. Definitely will feel like early summer as lows struggle to drop in the lower/mid 70s overnight. A quick glance at record warm low temps and the forecast lows shows we'll be really close to those records pretty much everywhere across the CWA.

MEFFER

LONG TERM

(Sunday through Tuesday night) Issued at 105 PM CDT Wed May 20 2026

In the grand scheme of things, the forecast is pretty much the same through this weekend through early next week. Multiple shortwave troughs will pass through the southeastern side of the main trough during this timeframe. Onshore flow will maintain high moisture and combined with strong daytime heating and lift from those shortwaves, 80-100% rain chances appear to be justified. Period rainfall totals of a few to several inches likely.for many.

MEFFER

AVIATION

(18Z TAFS) Issued at 105 PM CDT Wed May 20 2026

Radar imagery over the last few hours has begun to show increasing development of showers and thunderstorms with coverage expanding mainly along a broad line from KBTR to KMCB. All terminals will have at least some threat of TSRA during the afternoon and early evening hours, with TEMPO and PROB30 used as threat suggests. Should be a break in convection overnight at most terminals, but could get some fog development later tonight at terminals that get rain.

MARINE

Issued at 105 PM CDT Wed May 20 2026

A large area of high pressure will remain situated over the western Atlantic through the week and into next week. This will maintain light to moderate onshore flow through the time. Winds will bounce around headline criteria with sustained winds right around 10 knots, especially closer to the coast and west of the MS River, sometimes approaching 15 knots. As for showers and thunderstorms, daily isolated to scattered showers will be possible each day however the bulk of the coverage will remain inland. With any thunderstorms locally hazardous winds and waves can be expected.

MEFFER

LIX WATCHES/WARNINGS/ADVISORIES

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