textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 525 AM CDT Tue May 26 2026

- Heavy rainfall continues to be the main weather threat through the week. Some of the stronger storms will be capable of producing hourly rainfall rates of 1-3" per hour. With mostly saturated soils, high rainfall rates even over short periods could overwhelm drainage systems, leading to ponding of water in low lying and poor drainage areas. Localized flash flooding could also result in some roads becoming impassable, mainly in areas where the heaviest rain falls, or where multiple storms result in longer periods of moderate to heavy rain.

- A Flood Watch will be in effect through 7 PM Tuesday generally for areas from the New Orleans metro eastward through the Mississippi Coast including the north shore. Elsewhere, the flood threat will be lower, though isolated flooding could still occur. Additional Flood Watches may be needed, especially Thursday.

SHORT TERM

(Now through Thursday) Issued at 156 AM CDT Tue May 26 2026

So far a rather rare sight here recently...a relatively rain free night across the central Gulf Coast...at least for now. After locations across the MS Gulf Coast got a season's worth of rain in the last week this is very much welcome.

However, the same pattern that soaked most of the area (and flooded others) remains over the region today and the overall pattern will likely persist through the short term period. The active southwest flow will continue to bring shortwave after shortwave over the region generally one every 12-18 hours or so. Timing of the heaviest rainfall is still tricky as we have seen the last few nights even after losing peak heating we have managed to over perform in terms of overnight rainfall. That said, rain chances increase when the upper H5 impulses move over during peak heating where instability is maximized.

For Today, a few changes to note at least modest changes. There is a bit more dry air in the mid and upper levels filtering into the region. This means instability will likely be a bit higher with somewhat better lapse rates. Also, PWAT values are a good bit lower than yesterday with around 1.65-1.85" respectively. That said, we don't need PWATs to be near record territory for rainfall rates that may cause a problem with the recent soakers we have had. We will continue to FFA generally east of NOLA along I10 through this evening given the incredibly wet antecedent conditions, especially along the MS Gulf Coast. CAMs are a bit bullish with the parameters this afternoon. Delaying the convective initiation time to just afternoon allows for moderate instability to develop. Additionally, DCAPE values climb above 1000 J/KG leading to a conditional threat of a strong to severe storm with gusty winds being the main concern.

Wednesday features what could be a MCS to our west moving east with time out of Texas and then perhaps across the northern Gulf. The cold pool looks to arrive generally around the time of peak heating. Dry air in the mid levels decreases just a bit, but along this boundary and/or any mesoscale boundaries that develop, storms will again fire in the afternoon hours. PWATs slightly increase, but similarly it will not take much heavy rainfall to cause issues. Additional FFA's may be needed, but again timing and location for the heaviest rainfall is still tricky so opted not to issue headlines for Wednesday for now.

After a brief break Wednesday night, Thursday looks to start early with another impulse moving in later in the morning generating additional convection across the region. Thursday is a bit concerning because PWATs do bounce back over 2.0" once again and with the rather defined wave aloft expect more widespread showers and storms will develop and linger through the afternoon and early evening hours.

Temperatures, today look to be a bit warmer considering a later convective initiation time, but should still only climb into the lower to middle 80s. Wednesday looks to be a bit on the warm side as well, again with most of the convection waiting until later, but Thursday looks cooler due to more widespread earlier convection with most of the area only warming only into the lower 80s. (Frye)

LONG TERM

(Thursday night through Monday) Issued at 156 AM CDT Tue May 26 2026

The upper-level troughing stuck over the northwest Gulf within the subtropical jet will continue to provide prevalent southwest flow favorable for above normal chances for showers and storms, especially during the daytime hours, through Friday. Storm flow will continue to favor southwest to northeast motions within this upper- level flow, particularly with more organized convective activity coming out of southeast TX. However, exact timing, size, and strength of any of these convective systems is about as good as anybody's guess at this lead time.

Upper troughing will gradually scoot eastward into the SE CONUS causing more subtle shortwave ridging to move overhead this weekend which could tamp down PoPs though summertime afternoon pop-up convection would still be probable to provide some impacts to outdoor plans even if it's more isolated in nature.

By early next week, the global ensembles indicate that this unsettled weather pattern could eventually break where a stronger, more textbook, rex block attempts to establish across the north- central CONUS and strengthen east coast troughing that could help pivot upper-level flow into a more northwesterly orientation and promote advection of drier, continental air. This would bring about more climatologically normal chances for PoPs in the 20-50% range headed into Monday and Tuesday. This solution does appear to have some more run to run consistency, but I'm not trying to get anybody's hopes up just yet. (TJS)

AVIATION

(12Z TAFS) Issued at 525 AM CDT Tue May 26 2026

MVFR and perhaps lower CIGs/VIS will be possible through the early morning hours. Conditions will improve shortly after daybreak, however, like the last several days more convection is anticipated with the highest confidence for terminals east of the I55 corridor. Brief VIS/CIG reductions will be possible in and around convection. Otherwise, outside of SHRA/TSRA expect VFR conditions for the most part. Southerly winds will continue to be light to moderate, but may be a bit erratic in and around convection. (Frye)

MARINE

Issued at 156 AM CDT Tue May 26 2026

High pressure anchored over the western Atlantic will maintain light to moderate onshore flow across the local coastal waters. Daily showers and storms will be capable of producing locally hazardous winds and seas, with a few cells each day capable of producing winds in excess of 34 kts over the next few days. (Frye)

LIX WATCHES/WARNINGS/ADVISORIES

LA...Flood Watch through this evening for LAZ039-064-070-076>080-087- 089>093-098>100.

GM...None. MS...Flood Watch through this evening for MSZ077-083>088.

GM...None.