Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
Issued by NWS New Orleans/Baton Rouge, LA
500 FXUS64 KLIX 030632 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 1232 AM CST Wed Dec 3 2025 ...New SHORT TERM, LONG TERM, AVIATION, MARINE... .KEY MESSAGES... Updated at 1120 PM CST Tue Dec 2 2025 - With rather persistent cloud cover most of the evening and even holding on into the overnight hours the potential for freezing conditions has decreased precipitously - Another storm system will bring widespread rain and embedded thunderstorms to the area Thursday through Friday night. There will be at least a low-end threat of heavy rain with this system and two-day rainfall totals are currently forecast in the 2-4 inch range. Please check the forecast for updates in the coming days as forecast rainfall totals and associated flood threats will continue to be refined. && .SHORT TERM... (Today through this Evening) Issued at 1120 PM CST Tue Dec 2 2025 Clouds have plagued the area all night and we are not quite cooling as much as expected. This is going to have a significant impact on morning lows and we will likely remain abv freezing over most if not all of the area. Forecast focus is on the overnight period through the weekend but quickly today. Clouds could still be a little stubborn to start the day but eventually the low clouds should clear out but as soon as the occurs mid lvl clouds will quickly push in from the southwest this afternoon. This is the beginning of moisture returning which will increase much more rapidly overnight. Highs will be warmer today with upper 50s to mid 60s. /CAB/ && .LONG TERM... (Thursday through Tuesday night) Issued at 1120 PM CST Tue Dec 2 2025 Main forecast concern is Thursday through the weekend. Models continue to struggle some with placement of the rain, how much, and how fast long it lasts at times. The latest trend has been a renewed 3rd shot of rain over mainly coastal sections of the CWA Saturday night into Sunday. The biggest problem with the overnight forecast tonight and through Thursday is how models are handling the band of rain/convection with 2 distinct scenarios being advertised. One where the regional and global models have the higher rain across the northern half of the area and the other advertised by the CAMs which as one would expect try to surge the convection towards the higher instability and cut off the moisture for a good chunk of the northern half of the CWA. Given the highly uncertain and low confidence in the forecast stuck pretty close to the latest NBM guidance. It is showing high PoPs for almost the entire area from overnight tonight till early Sunday and lets be honest it will not rain over the entire area that entire time. However, trying to explicitly time things out and focus on specific locations is mostly futile right now. So a quick look at the pattern and setup. Overnight tonight with a rather ugly L/W trough stretching to the southwest from the Hudson Bay into the Pacific well southwest of southern CA. This is already putting us under increasing west-southwest to southwest flow aloft which is easily visible on GOES19 with clouds streaming from the Pacific across Mexico and now into southern TX and the western Gulf. That said there are a few keys pieces of energy embedded in the broad L/W with the one that will have the greatest say over the area currently moving south over CA. This stronger s/w will begin to split with part of it heading back to the south-southwest along the backside of the trough and the rest trying to round out just south of the 4 corners. This s/w will start to flatten out and eventually just merge becoming more part of the L/W trough. That said it will add a lot of energy with the mid lvl flow greatly responding across the southern Plains, the Lower MS Valley and into the TN Valley Thursday. Even though it just becomes part of the whole setup and loses its identity it will provide enough support to see low pressure start to take shape across the TX coast early Thursday with an inverted trough axis extending to the northeast across southern LA. If the s/w can hold onto its identity a little more it may try to help to draw the broad sfc low and inverted trough a touch more north however, if it just quickly merges with the main flow we will likely see a weaker broad sfc low along the TX coast and the inverted trough and possible warm front along the coast. This will have implications on rainfall especially amounts and location. This is where the the two different scenarios emerge. First all model solutions have a weak sfc low and the bigger issue is how the handle the evolution of convection and the locations of the inverted trough and warm front. The global and even regional models draw things farther north where the CAMs which are just now getting into the time frame really allow convection to dictate and eventually surge the convection cold pool style towards the coast and the better instability. That would make sense but am hesitant given as this could just be feedback as the CAMs just feed into themselves. The strong s/w and its impact across the southern Plains make me initially think it will try to draw things a touch farther north. The key will be where convection as as we cross midnight tonight and see it it is continuing to expand ENE or if the eastern edge of the precip isn`t quickly expanding ENE and actually holding onto a harder edge and moving more east with a slight southern component suggesting it trying to be drawn towards the coast. This also would likely be self fulfilling as convection would try to strengthen the sfc low over the coast or coastal waters and thus reinforce convection trying to become more coastal. Again if I had to choose one side over the other I am probably slightly leaning towards the global and regional models. The forcing is not overwhelming to really lead to so strong of convection that cold pooling would take over. In addition the strongest forcing is still north so convection will likely remain focused on the inverted trough which will eventually get anchored over the northern half of the CWA early Thursday through the midday hours. As for potential of heavy rain. The biggest feature is rapidly increasing moisture overnight tonight. PWs will be abv the 90th percentile. So convection will already be efficient and combine that with some elevated instability to work with and there could be a band of locally heavy rain. Obviously the other concern would be training given the band will likely be parallel to the mid lvl flow so the main issue would be where that sets up. Most of the area had been rather dry and even with vegetation likely in a more dormant phase the dry soils and low rivers can handle quite a bit of rain. The issue would be if this lines up directly over any of our larger urban areas. Where runoff is always a problem if the rain comes down hard enough. That is just round one as the trough starts to buckle a little with some the closed low in the Pacific finally sliding east with the L/W trough. This will lead to a break in the rain late Thursday and possible Thursday night however there will still be spotty showers out there overnight. The next round of rain be Friday as stronger forcing spreads out over the area. Even though the forcing will increase it will be broad with no real focus and still some weak inverted trough laying up along the southeastern half of the CWA Friday. Rain will likely be lighter Friday especially over the northwest. As that moves to the east we will probably see another break with spotty light rain overnight Friday and into Saturday but a third area of low pressure could develop over the southern Plains or even the western Gulf and as the trough axis gets closer we will see a 3rd round of rain try to impact the region overnight Saturday and into Sunday. One last thing to mention and it was brought up in the Marine section. There is a window for minor coastal flooding Thursday night into Friday during high tide. 24 to 36 hours of easterly to east- southeasterly flow increasing in strength and occuring at the same time as peak tides this month should lead to some minor coastal flooding across coastal Hancock county and east facing shore of SELA. /CAB/ && .AVIATION...Thursday night (06Z TAFS) Issued at 1120 PM CST Tue Dec 2 2025 Clouds are finally trying to clear out of the area with the southwestern edge eroding to the north. Still quite a bit of low cigs over most of the around mainly hanging around 1400 to 2k ft. This has all terminals currently in MVFR and that will likely continue to be the case through the early morning hours. Cigs will finally start to lift and scatter out from southwest to northeast after 12z and maybe even slightly later than that. Mid lvl clouds will begin to move back in this afternoon and evening as moisture returns. Rain should hold off till after 6z for most terminals with BTR haveing the greatest risk of seeing rain and even MVFR cigs again before 6z. /CAB && .MARINE... Issued at 1120 PM CST Tue Dec 2 2025 High pressure has moved in but will continue to sliding east quickly leading to light return flow by midday/early afternoon today. Weak low pressure will begin to develop along the Texas coast tonight and slowly drift east-northeast Thursday along the coast. This will tighten the pressure gradient especially east of the Mississippi River delta. Winds will increase with moderate to strong east- southeast to easterly winds. This will have multiple impacts with Small Craft Advisory conditions expected Thursday into Friday but the increase in onshore winds will combine with the increasing tidal cycle at the end of the week likely leading to at least some minor coastal flooding. Main concern will be east facing shores of Orleans, St Bernard, Plaquemines, and far southeastern St Tammany. In addition coastal Hancock around Waveland will also deal with some minor coastal flooding Thursday night through Friday morning. Winds will relax and return to offshore late Friday and Friday night but another weak surface low will develop Saturday moving across the coastal waters late Saturday bringing another brief period of moderate to strong winds. /CAB/ && .PRELIMINARY POINT TEMPS/POPS... MCB 43 31 58 43 / 0 0 0 70 BTR 47 32 61 48 / 0 0 0 80 ASD 51 33 60 43 / 0 0 0 60 MSY 51 42 63 52 / 0 0 0 70 GPT 53 35 59 45 / 10 0 0 50 PQL 55 33 60 41 / 10 0 0 30 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...CAB LONG TERM....CAB AVIATION...CAB MARINE...CAB