Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
Issued by NWS New Orleans/Baton Rouge, LA
172 FXUS64 KLIX 051128 AAA AFDLIX Area Forecast Discussion...UPDATED National Weather Service New Orleans LA 628 AM CDT Sat Sep 5 2026 ...New AVIATION... .KEY MESSAGES... Updated at 626 AM CDT Sat Sep 5 2026 - Scattered to numerous showers and storms are forecast through the holiday weekend. While the overall severe weather threat will be low, one or two storms could become strong to severe. The primary threats will be strong wind gusts, frequent lightning and periods of heavy rain leading to localized flash flooding. - Above normal temperatures expected most of the 7-Day forecast period. Afternoon heat indices will generally range from 100 to 108 degrees. && .SHORT TERM... (Now through Labor Day) Issued at 136 AM CDT Sat Sep 5 2026 An upper level ridge axis extend from Canada, across the Central Plain, and down to the western Gulf along the TX coast. That puts the local area along its southeastern periphery. At the same time, troughing begins to deepen across the eastern CONUS today, with the resulting weakness aloft continuing to support scattered to numerous showers and thunderstorms. Current GOES-16 Blended Total PW indicates 2.3+ inch precip water values across all of southeast LA and southwest/coastal MS. Those values will remain in place today. As mainly afternoon storms initiate along seabreeze or other mesoscale convergent boundaries, highly saturated column will support quite efficient precip processes and thus the potentially for locally heavy rainfall which could lead to flash flooding. For temps, it`ll be moreso about convective timing and overall coverage. Latest forecast temps are down slightly from 24 hrs ago as more rain and cloud cover will probably again hold highs to upper 80s for the most part. As the ridge shifts farther west Sunday and trough to the east digs south, flow aloft becomes somewhat more northerly. Forecast profiles may then become slightly drier in the mid levels compared to today the period. If this occurs, increasing DCAPE and a better-defined inverted-V structure could modestly increase the potential for isolated strong downbursts, particularly where storms develop after prolonged heating. POPs are down a bit as well, so more likely to see highs back up into the lower 90s. On Labor Day, the forecast area will remain positioned on the southeastern periphery of the upper level ridge centered over the Central Plains and a longwave trough across the eastern seaboard. This will place the region beneath a deep mid to upper level north- northeasterly flow pattern. Previous model runs indicated that a backdoor front associated with the trough to the east would reach the CWA. Not so sure with latest runs and tend to agree with the front stalling just to the east of the forecast area. It seems to not really matter much as ample moisture will still be in place and combined with above normal temps, still going to have widespread convection with POPS well over 50% for some areas. Heat index values will also be approaching to possibly exceeding advisory levels for Labor Day. So for this holiday weekend, staying weather aware will be quite important when outdoors. && .LONG TERM... (Tuesday through Friday) Issued at 136 AM CDT Sat Sep 5 2026 By the time Tuesday arrives, the deep ridge over the western states will have flattened out a bit, and will encompass much of the area from the desert SW out to the eastern seaboard. A weak inverted trough moving across the northern Gulf will be able to continue copious moisture, leading to the highest pops of the long term period. There is a bit of mid level dry air on Tuesday so of all the days in the long term, this would be the day with a higher chance of damaging winds in any the storms that develop. The weak surface low shifts westward Tuesday night into Wednesday, taking the highest pops with it but with the lingering moisture and southerly flow, pops remain elevated, especially along the far southern coast. Given the overall lack of strong ridging over the southern half of the states through the week, the combination of that, light winds, weak disturbances moving across the Gulf and PW values at 2 inches or above, daily summertime thunderstorms will persist each afternoon. It`s likely that the long term NBM pop values are a tad too low as we go into Wed through Fri, especially along the southern half of the area. The ongoing rain and moisture looks to keep high temps in the lower 90s but the moisture will also put heat index values in the 105-107 range in some areas. If pop coverage is lower than expected, and temps get any higher, Heat Advisories will be likely for a few days next week. && .AVIATION... (12Z TAFS) Issued at 627 AM CDT Sat Sep 5 2026 Mostly VFR conditions are forecast through most of the morning hours. Showers and storms will begin to develop late morning near coastal terminals from KGPT to KASD and those south of Lake Pontchartrain. PROB30s will be need for those same sites during the afternoon hours. With loss of daytime heating, convection should gradually dissipate and VFR conditions will then prevail. Any terminals impacted by storms would see temporary IFR or MVFR visibility and ceiling reductions along with frequent lightning. MEFFER && .MARINE... Issued at 136 AM CDT Sat Sep 5 2026 A surface ridge will become established generally across the central and eastern Gulf through Monday night. Wind field around this feature will support west to southwesterly flow over the local coastal waters. Pressure gradient should be rather weak, so expect winds 10kts or less with seas/waves 1-2 feet. Latest medium range model solutions are beginning to indicate the chance for a backdoor cold front reaching the northern Gulf is steadily decreasing. They show the trough digging south a bit farther east than previous runs which means ridge aloft is slightly stronger. That combo makes it harder for front to actually make it here early next week. May see even weaker winds/seas as the front tries to move in, but then onshore flow again becomes re- established. Meanwhile, the main impact in both short and long term periods will be daily showers and thunderstorms. Expect locally higher winds and seas in and around convection. && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...ME LONG TERM....ME AVIATION...ME MARINE...ME