Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
Issued by NWS New Orleans/Baton Rouge, LA
720 FXUS64 KLIX 260504 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 1204 AM CDT Sat Sep 26 2026 ...New SHORT TERM, LONG TERM, AVIATION, MARINE... .KEY MESSAGES... Updated at 1018 PM CDT Fri Sep 25 2026 - Outside of a few isolated showers mainly across coastal southeastern Louisiana, quiet weather with warmer than normal temperatures will persist through the beginning of next week. - During the latter part of next week, a period of more active weather appears likely. While there is still significant uncertainty regarding the specifics, heavy rain could become a concern mainly Friday and into the weekend. && .SHORT TERM... (Now through Tuesday) Issued at 1018 PM CDT Fri Sep 25 2026 Very dry cool mornings and warm days through at least Tuesday, which is reminiscent of October type weather. Strange thing is September is normally wetter than October, and this may end up being the case this year as well, but it won`t seem like it as we move from September into October this time, but we`re getting ahead of ourselves. The dry air will hang around through Tuesday so enjoy it while its here because it will get replaced with deep moisture as we move through next week. But, the good thing is the dry air will be back at some point during October. && .LONG TERM... (Tuesday night through Friday) Issued at 1018 PM CDT Fri Sep 25 2026 Through Wednesday night the region will experience increased negative vorticity advection and subsidence as a southern stream shortwave ridge axis remains centered over the region. This increased ridging aloft will warm and dry the mid and upper levels of the atmosphere, and this will lead to weak mid-level lapse rates of less than 5.0C/KM. This is reflected in the lack of instability as noted by SBCAPE values of around 500 J/KG. The end result will be a continuation of the dry and warm pattern through Wednesday night. Highs will continue to run around 5 degrees warmer than average in the lower 90s. Fortunately, the dry air in place will keep heat index values in check with most areas experiencing heat indices peaking in the upper 90s. The dry air will also allow for decent radiational cooling each night. Overnight lows should fall into the upper 60s inland and the low 70s along the coast Tuesday and Wednesday night. As we move into the latter part of the week, the ridge over the area will push to the east as a vigorous southern stream shortwave trough moves into the southern Plains and Texas. This trough will have deeper tropical moisture associated with it as the remnants of Hurricane Polo merge into the system. Fortunately, the heaviest rainfall on Thursday and Thursday night will remain west of the area, but increasing deep layer southeasterly flow in advance of the trough and a broad region of higher positive vorticity advection will support both PWATS rising back to the median for late September and increasing convective activity. Although there will some support aloft, the convection will be largely diurnal in nature with scattered showers and thunderstorms peaking in the afternoon hours over the region. By Thursday night, most of the activity will dissipate except out over the coastal waters. Temperatures will also be closer to average with highs in the upper 80s on Thursday and lows in the upper 60s and lower 70s for Thursday night. A much wetter period of weather will then set up across the Gulf South for Friday and Friday night as the deep layer southerly flow pattern ushers in a surge of tropical moisture. PWATS will increase to around 1.75 inches and this will allow for continued scattered shower and thunderstorm activity to develop and for the rainfall rates to increase to 1 to 2 inches per hour. The broad region of positive vorticity advection and favorable forcing aloft will combine with a series of weak vorticity impulses to support several rounds of showers and thunderstorms throughout Friday and Friday night. Given the repeated periods of rain, conditions will quickly start to saturate and some flooding issues may begin as early as Friday afternoon. Temperatures will also be cooler due to the increase in cloud cover and rainfall with highs generally staying in the mid 80s on Friday and lows dipping into the low 70s. && .AVIATION... (06Z TAFS) Issued at 1018 PM CDT Fri Sep 25 2026 VFR through this cycle. && .MARINE... Issued at 1018 PM CDT Fri Sep 25 2026 Easterly winds around 15 knots will ease west of the Miss River early this morning. Winds over all coastal waters will become light and sometimes variable through Monday. Winds will become predominantly SE by Tuesday at around 10 knots the rise further into mid next week to around 15 to 20 knots as a cold front approaches the coast. && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...TE LONG TERM....PG AVIATION...TE MARINE...TE