textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 641 PM CDT Fri May 22 2026

- Torrential rainfall possible with any stronger storms through this weekend. Rainfall rates of 2-5" per hour are possible and could easily overwhelm drainage systems.

- High rain chances through the next several days. Areal 7 day rainfall totals will range from 4 to 7 inches

SHORT TERM

(Now through Monday night) Issued at 130 PM CDT Fri May 22 2026

Most of the country is under varying portions of upper level trough. A shortwave embedded within the broad scale trough is currently tracking northeast across the Lower Mississippi River Valley. The low level dynamics are certainly better farther north into central MS. However, 500mb winds aloft are forecast to increase this afternoon from that shortwave which aide into convective organization. Moisture rich airmass remains in place, each WFOLIX sounding measuring near record PW for this time if year. One surprise on this morning's flight was just how much CAPE we have throughout the column from much steeper mid level lapse rates than previously seen. Localized hourly rainfall rates of 2 to 5 inches per hour will be possible within the strongest cores this afternoon and evening. The overall movement of storms might be faster than yesterday based on mean flow model sounding data, but updshear/downshear vectors are quite close in direction and bring a higher probability of thunderstorm training. That combined with intense rainfall rates definitely would promote localized flash flooding, particularly in urban and poor drainage areas.

Going into the overnight period, meso and global models suggest a lull in convection, lasting well into Saturday morning. May be Saturday afternoon before convection develops. Numerous showers and thunderstorms capable of producing torrential rainfall and localized flooding impacts expected with nearly 100% coverage as another shortwave slides through the region.

LONG TERM

(Tuesday through Thursday night) Issued at 130 PM CDT Fri May 22 2026

An unsettled and moisture airmass will persist through much of the extended forecast period as broad ridging remains suppressed to the south and east while upper level troughing generally remains in place each day. As seen recently, shortwave impulses will continue to enhance shower and thunderstorm development. Daily rounds of showers and thunderstorms are expected each day through the weekend and into early next week. Precipitable water values generally between 1.8 and 2.2 inches will continue to support efficient warm rain processes and locally heavy rainfall with any thunderstorms that develop. Rainfall coverage may fluctuate somewhat day to day depending on subtle mesoscale boundaries, convective overturning from prior day activity, and shortwaves passing through the base of the broad scale trough. Its the Sunday impulse that is forecast to bring Slight Risk of Flash Flooding Sunday as it moves across the CWA. High temperatures will remain near climatological normals but lows above normal due to increased cloud cover and precipitation coverage.

Although widespread flooding is not anticipated at this time, hence no Flash Flood Watch issued with this forecast period, isolated nuisance flooding and localized flash flooding issues will remain possible each day, especially in urban areas and locations that receive repeated rounds of convection.

AVIATION

(00Z TAFS) Issued at 641 PM CDT Fri May 22 2026

Lingering thunderstorm activity along a weak boundary extending from ASD to HDC will continue for the next 1 to 2 hours at a minimum. TEMPO groups are in place through 04z at these terminals to reflect the ongoing convective risk. The remainder of the terminals will continue to see improving conditions this evening into tonight as a rain cooled and more stable airmass develops. This more stable airmass will also promote some low stratus and fog development around daybreak tomorrow at MCB, HDC, and BTR resulting in a few hours of IFR impacts between 10z and 13z. By 14z, daytime heating and increasing instability will once again allow for scattered thunderstorm activity to start forming, and all of the terminals have PROB30 wording in place to reflect this convective risk tomorrow. Any convective impacts will be short- lived at an hour or less, but periods of IFR visibility restrictions and lightning can be expected as these storms move through.

MARINE

Issued at 130 PM CDT Fri May 22 2026

A large area of high pressure will remain anchored over the western Atlantic throughout the forecast period. This will maintain light to moderate onshore flow through the time. Winds should generally right around 10 knots. Periods of near 15 knots possible, especially in open Gulf waters. 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.

LIX WATCHES/WARNINGS/ADVISORIES

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