


Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
Issued by NWS New Orleans/Baton Rouge, LA
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940 FXUS64 KLIX 071721 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 1221 PM CDT Mon Jul 7 2025 ...New AVIATION... .SHORT TERM... (Today through Wednesday night) Issued at 1106 PM CDT Sun Jul 6 2025 Late afternoon and evening rainfall across southwest Mississippi and the Pearl River basin may locally enhance low-level RH values which in combination with clearing skies and near-calm winds could result in light patchy fog development across areas near water bodies and low-lying areas. However, dense fog is unlikely to develop given current guidance. McComb is already 69/68 and Bogalusa is 74/71 from the rain-cooled air with calm winds which could lend a bit more confidence we`ll see these patchy fog conditions, but nonetheless significant impacts are not anticipated. A weak upper trough centered just off the coast of Louisiana is the primary feature that locally enhanced more scattered storm coverage on Sunday, and we can expect relatively more of the same today. The key difference today does appear to be that the best forcing with this upper trough will continue to gradually move away which could limit coverage ever so slightly compared to yesterday, but HREF guidance continues to pinpoint highest PoPs of 60-70% focused along the Atchafalaya Basin extending east to the I-55 corridor. Though there was some showers and storms that attempted to fire up along the lake/sea breeze in St. Tammany and coastal MS on Sunday, the lake shadow and drier air filtering in from the northeast was an inhibitor and this should still be true today so PoPs are closer to 30-50%. By Tuesday, the upper trough will have backed away and weakened over the northwest Gulf allowing rising mid-level heights and high pressure to nose itself farther west over the northern Gulf coast. Latest 00z guidance continues to suggest Tuesday will carry the least amount of storm coverage and thus PoPs have been dropped 10-15% below NBM guidance to reflect the lower confidence in measurable precipitation. That said, PoPs are still in the 40-60% range, especially along and west of the I-55 corridor where moisture and less suppressive atmospheric conditions will still be present. Our attention then turns to a weak shortwave trough currently situated over the Prairie Provinces of Canada which will dip down around the eastern periphery of the rebuilding SW CONUS ridge on Tuesday. This weak shortwave will arrive to the Mid Mississippi River Valley by Wednesday, slow down as it gets stuck in between the ridges on either side of it, and begin to lose its coherence. As it does so. This will begin the gradual trend back up in PoPs each afternoon starting Wednesday afternoon and continuing into the latter half of the week. && .LONG TERM... (Thursday through Sunday night) Issued at 1106 PM CDT Sun Jul 6 2025 During the second half of the week, deep moisture will increase across the area with precipitable water forecast to be near or just above 2 inches across most of the area. This should lead to a further increase in convective coverage with storms becoming more numerous to widespread Thursday and Friday. The increase in moisture will also lead to potential for more efficient rainfall. While widespread heavy rain is not forecast, individual storms will be capable of producing high rainfall rates with a couple inches of accumulation in a relatively short period of time. By the weekend, it`s less clear whether we`ll see this troughing linger and continue to enhance afternoon PoPs or if the ridge will nose back in enough to allow temperatures to nudge back closer to the mid to upper 90s. Regardless, the muscle memory of this pattern continues to support persistence forecasts of near or slightly above normal temperatures with elevated chances for afternoon storms each day, and that will continue until we see a considerable shift to the longwave weather pattern at a time TBD. && .AVIATION... (18Z TAFS) Issued at 1216 PM CDT Mon Jul 7 2025 Currently VFR conditions across all terminals, expected to remain so through the period. Exception will be areas of convection in the vicinity of terminals that may lower CIGs and VIS to MVFR for the duration of the convection. && .MARINE... Issued at 1106 PM CDT Sun Jul 6 2025 Marine conditions will be benign through the period outside of any localized impacts from convection. Winds will remain light out of the south to southwest in an onshore direction through the work week. A fairly typical summertime convective pattern is expected with showers and storms developing during the late night, peaking during the morning hours, and diminishing through the afternoon and evening. Storm coverage over the waters will increase in coverage during the morning hours each morning starting Wednesday into the weekend with widespread storms most likely on Thursday. && .PRELIMINARY POINT TEMPS/POPS... MCB 71 92 72 92 / 20 50 10 70 BTR 73 92 74 93 / 10 50 10 70 ASD 73 93 73 92 / 10 40 10 70 MSY 77 93 78 93 / 10 50 10 70 GPT 75 91 75 92 / 10 30 10 60 PQL 73 92 73 92 / 10 30 20 60 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...TJS LONG TERM....TJS AVIATION...DS MARINE...TJS