275 FXUS64 KLIX 080444 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 1144 PM CDT Mon Jul 7 2025 ...New SHORT TERM, LONG TERM, MARINE... .SHORT TERM... (Tonight through Wednesday night) Issued at 1142 PM CDT Mon Jul 7 2025 Rain-saturated southwest Mississippi is observing locally enhanced low-level RH values from late afternoon storms which in combination with clear skies and near-calm winds will result in light patchy fog development across areas near water bodies and low-lying areas again this morning around sunrise. McComb is 72/71 from the rain-cooled air with calm winds, just like yesterday, which lends confidence we`ll see patchy fog conditions, but significant impacts from dense fog are not anticipated. The weak upper trough has continued to back away and weaken over the northwest Gulf allowing rising mid-level heights and high pressure to nose itself farther west over the northern Gulf coast today. Latest 00z guidance continues to suggest less storm coverage compared to prior days and NBM guidance has fallen in line with this idea finally. 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. Confidence is higher for areas along the immediate coast of SE St. Tammany and coastal MS to remain dry once again today as the lake and seabreeze push inland before showers and storms attempt to develop and this is reflected by 20-40% PoPs, which still may be a tad generous. Our attention then turns to a weak shortwave trough currently situated over North Dakota which will dip down around the eastern periphery of the rebuilding SW CONUS ridge today. 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 Monday night) Issued at 1142 PM CDT Mon Jul 7 2025 Deep moisture will increase across the area with PWAT values forecast to be near or just above 2 inches across most of the area in conjunction with the approaching weak shortwave trough. 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 more efficient rainfall within the storms that develop. While widespread heavy rain is not forecast, individual storms will be capable of producing high rainfall rates exceeding 3 inches per hour that can cause quick accumulations and overwhelm street drainage systems. The more zonal orientation of this weak shortwave portrayed in the global model guidance on Thursday just to the north of the CWA does leave room for some uncertainty in exactly how widespread convection will be despite NBM guidance advertising 80% PoPs almost areawide, and it`s possible we see some spatial and magnitude adjustments as this comes into view of CAM guidance. The shortwave troughing will linger into Friday in the weakness between ridges so afternoon PoPs will remain elevated higher than climatological norms. 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 get closer to the mid to upper 90s. Heat indices could push closer to the 105-110F range if so. 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 an appreciable shift to the longwave weather pattern at a time TBD. && .AVIATION... (00Z TAFS) Issued at 643 PM CDT Mon Jul 7 2025 Lingering stratiform showers from afternoon storms remain present over SW Mississippi and adjacent parishes, but will continue to gradually clear out during the next hour. VFR conditions will be prevailing at all terminals through the overnight hours with exception to MCB where MVFR VIS from patchy fog will likely occur again given the heavy rainfall late in the day, just like yesterday. Although storm coverage will be a bit more isolated than prior days on Tuesday, still have high enough probs to add PROB30s to most terminals with respective timings of onset happening from the coast at around 1700-1800 UTC to inland terminals through 2000-2400 UTC. Lowest confidence in impacts are at ASD (due to lake shadow), MCB, and GPT on Tuesday. Have added a PROB30 for a narrow window at GPT in which a storm or two could develop on the seabreeze nearby before it lifts north. && .MARINE... Issued at 1142 PM CDT Mon Jul 7 2025 Marine conditions will be benign through the period outside of any localized impacts from convection. Winds will remain between 5 to 15 knots 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 71 92 / 30 50 20 70 BTR 74 92 74 92 / 10 70 10 80 ASD 73 92 74 92 / 10 40 10 60 MSY 77 93 77 94 / 10 50 10 80 GPT 75 91 75 92 / 10 30 20 50 PQL 73 92 73 92 / 10 30 10 50 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...TJS LONG TERM....TJS AVIATION...TJS MARINE...TJS