textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 539 AM CDT Wed May 27 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 is in effect for our entire area through this evening.

SHORT TERM

(Now through Saturday Night) Issued at 204 AM CDT Wed May 27 2026

Eyes are focused upstream this morning watching a MCS over Texas move generally eastward. CAMs have this feature moving into the region later this morning/early afternoon, but weakening as it nears the CWFA. The mid level dry air that helped suppress convection slightly yesterday will continue to moisten over time. PWATs approach 2.0" again this afternoon so the convection with the MCS may contain locally heavy rainfall once again (mostly west of I55). The MCS decays later this morning and early afternoon, but the boundary along with sea/lake breeze boundaries will be the focus for additional diurnal driven convection. The main threat will be heavy rainfall. Since the dry air aloft vanishes this afternoon, there is less of a wind threat with the cells (evident by DCAPE values half of what they were yesterday).

Going into Thursday both mesoscale and global guidance is trending drier. Because of this trend didn't extend the FFA in time given the lower confidence and somewhat large shift in the trends. Going into late week and into the upcoming weekend, there is finally a small pattern shift taking place. The active southwesterly flow aloft evolves to a more zonal and even eventually some upper level ridging develops over the forecast area. This will suppress rainfall just a bit, but still diurnally driven convection will be possible each afternoon, just a bit more limited in coverage than the last week or so. As for temperatures, with the lower heights temps will be a bit under climo. But going later into the short term temperatures warm back to average for this time of year, which is getting closer and closer to 90 degrees. (Frye)

LONG TERM

(Sunday through Tuesday) Issued at 204 AM CDT Wed May 27 2026

The specifics of the long term outlook are still a bit hazy. It is a certainty that we will be seeing continued rain through about the middle of next week. However, the long term global models are not in full agreement of how we get there. The primary difference is treatment of how an upper low behaves as it drops out of the high latitudes toward New England and evolves through the early weekend and then moves offshore as a closed low over the OH Valley vs an open trough centered off the Canadian Maritime provinces. As mentioned, model solutions bring us rain and the current consensus is that we move to a more summertime feel of afternoon showers and thunderstorms with on the order of 1/2 inch of rain every day, and of course local amounts could be somewhat higher or lower. Fortunately, these amounts should be low enough that the localized flash and river flooding we've seen this weekend and early workweek will not be repeated. The other positive note is that although there may be some thunderstorms, we aren't expecting any full-blown severe weather. (DS)

AVIATION

(12Z TAFS) Issued at 551 AM CDT Wed May 27 2026

VIS/CIG reductions possible through the morning hours with improvement occuring right after sunrise. Through today expect VFR conditions outside of convection. Once again, showers and storms will be possible during the afternoon and early evening, but overall confidence in coverage is on the low side. Later tonight more CIG/VIS reductions will be possible, especially locations that receive rainfall today. Winds will remain southerly and will continue to remain light to moderate. Around thunderstorms expect more gusty and erratic winds. (Frye)

MARINE

Issued at 204 AM CDT Wed May 27 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 LAZ034>037-039-046>048- 056>058-064-070-071-076>087-089>100.

GM...None. MS...Flood Watch through this evening for MSZ068>071-077-083>088.

GM...None.