textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 1237 AM CDT Thu May 21 2026

- Expect high rain chances through the next several days. 7 day rainfall totals will range from 3 to 7 inches across much of south MS and SELA.

SHORT TERM

(Now through Sunday) Issued at 1237 AM CDT Thu May 21 2026

Upper pattern over the local area continues to be dominated by southwesterly flow due to a large trough running from Montana to southern California. Several shortwaves are moving through that southwesterly flow with one exiting the local area this evening, and the next one already over the Rio Grande Valley in Texas, and a third over Baja California. At the surface, the Bermuda high is pretty much where it is supposed to be, and there is a frontal boundary that extends from near Nashville Tennessee to Austin Texas. Locally, rain showers continue to dissipate across the area. Skies were mostly cloudy at midnight CDT with temperatures in the 70s and dew points in the lower 70s.

Very little is going to change in the upper pattern through the weekend. The upper flow will remain southwesterly and shortwave impulses will rotate through the area at 18 to 24 hour intervals, producing rounds of showers and thunderstorms. Precipitable water values remain above the 90th percentile for late May (>1.75 inches), approaching daily maxima. Each round of storms will be capable of producing 1-2 inches of rain in a short time, and if cells repeat over an area, localized flooding issues could occur. Not seeing any indications of organized heavy rain at this point, but multiple days of heavy rain would point to needing a Flood Watch over portions of the area sometime in the next few days. Cumulative totals of expected rain over the next 5-7 days would point at most areas getting at least 3 inches of rain, with some potential to get double or triple that in a few aeras.

Potential for thick clouds and precipitation leads me to believe that high temperatures in the mid 80s will be reasonable in most cases, with lows around 70.

LONG TERM

(Sunday night through Wednesday) Issued at 1237 AM CDT Thu May 21 2026

The new workweek will be very similar in terms of overall pattern. The H5 flow will remain an active southwesterly flow. Upper level short waves/vorts will continue to develop and move downstream, which will help generate convection especially during peak heating in the afternoon hours. Outside of an isolated strong wind gust or two, the main concern will likely be ongoing hydro concerns from the active pattern continuing from the short term period into the long term. PWAT values between 1.75-2.00" respectively will be more than enough for efficient rates. Higher rates over locations that may receive excessive rainfall prior to the long term will be most at risk. This will likely be west of the I55 corridor closer to the best upper level ascent (again mainly during the peak heating hours).

Temperatures for the long term will be relatively unchanged from the short term. Generally lower to middle 80s for max temperatures, which is around average for this time of year. Cloudiness and rainfall will help along with slightly lower heights and thicknesses especially early in the workweek as a rather robust upper level low develops over the southern Plains and Red River Valley. (Frye)

AVIATION

(06Z TAFS) Issued at 1237 AM CDT Thu May 21 2026

Convection this evening across LA and SW MS terminals has decreased to isolated coverage prior to 06z. Overnight, MVFR or lower conditions will be possible with locations receiving rainfall mostly likely to see IFR conditions. Otherwise, convection will increase once again by afternoon and impact most of the sites outside of GPT, with dissipation in most areas by 01-02z Friday. Light to moderate southerly winds expected.

MARINE

Issued at 1237 AM CDT Thu May 21 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.

LIX WATCHES/WARNINGS/ADVISORIES

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