Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
Issued by NWS New Orleans/Baton Rouge, LA
684 FXUS64 KLIX 300512 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 1212 AM CDT Sat Aug 30 2025 ...New SHORT TERM, LONG TERM, AVIATION, MARINE... .SHORT TERM... (Today through Sunday) Issued at 1205 AM CDT Sat Aug 30 2025 Upper troughing and ridging has shifted a few degrees eastward from the last few days with an upper low over the St. Lawrence River Valley, and the base of the trough near the Georgia coast. Ridging was from Texas through the northern Plains. A frontal boundary was sitting east-west near the Interstate 10 corridor. Much of the afternoon convection had dissipated by mid-evening, but a shortwave near Interstate 20 has reactivated showers on the edge of the drier air/front since 10 pm. Precipitable water values of 2.2 inches were noted on the LCH and LIX evening soundings, so any convection that does develop will have the potential to produce locally heavy rainfall through at least the afternoon hours today. Drier air is expected to work into the area from the north on Sunday, with precipitable water values forecast to fall into the 1.5 to 1.7 inch range. This should mean less in the way of clouds and precipitation from about Interstate 10 northward. Areal coverage north of Interstate 10 is expected to be mainly isolated Sunday afternoon, with scattered or better coverage from about the Houma- Thibodaux area southward. High temperatures today are likely to remain in the 80s, although one or two sites could hit 90. For Labor Day, highs should be a few degrees warmer, especially north of Interstate 10. && .LONG TERM... (Sunday night through Friday) Issued at 1205 AM CDT Sat Aug 30 2025 After several days of the ECMWF family of guidance being more aggressive than the GFS in pushing the frontal boundary out into the Gulf, the 12z model guidance flipped, with the GFS being the more aggressive solution and the ECMWF hugging the coast. The end result becomes a wash for the NBM with little change in the PoP numbers, with PoPs ranging from about 30 percent north to 60 percent along the lower southeast Louisiana coastal parishes Monday and Tuesday afternoons as the upper trough axis retreats westward toward the local area. Northerly flow will continue to push drier air into the area for the end of the week, with precipitable water values in the GFS model runs falling to around 1.3 inches, which is around the 25th percentile for early September. This should mean little or no rain by Thursday and Friday. Highs are likely to be in the upper 80s to around 90 for most of the area for the first half of the week. With more sunshine toward the end of the week, temperatures creeping above 90 may be a little more widespread. Where a difference may be noticed is in low temperatures during the second half of the week, where overnight lows in the 60s could overspread much of the northern half of the area, and potentially even into the Houma-Thibodaux area. && .AVIATION... (06Z TAFS) Issued at 1205 AM CDT Sat Aug 30 2025 Terminals were generally VFR at forecast issuance, with the exception of KMCB, where IFR ceilings had moved in to the north of a frontal boundary. There was a thin line of SHRA along this boundary that will continue to creep southward overnight. There was somewhat deeper convection offshore, but it is highly questionable whether TSRA will impact even coastal terminals prior to sunrise. As the boundary shifts southward through the first 6 hours of the forecast, MVFR to IFR ceilings could overspread KBTR, KHDC and perhaps KASD. Conditions should improve to at least MVFR by mid morning, with SHRA/TSRA possible from late morning through the afternoon hours before most dissipate prior to sunset. Expect VFR conditions during the evening hours as drier air overspreads most or all terminals. && .MARINE... Issued at 1205 AM CDT Sat Aug 30 2025 The main marine concern during the next few days of the forecast period will be the threat for thunderstorms that could produce locally higher winds and seas. Gusty outflow winds upwards of gale force are the main threat with any stronger thunderstorms. This pattern continues into early next week as a cold front gradually pushes into the coastal waters. The current wind forecast indicates generally offshore flow by late Sunday afternoon for most or all of the waters as the front pushes in from the northeast. && .PRELIMINARY POINT TEMPS/POPS... MCB 85 69 87 68 / 30 10 20 10 BTR 88 72 90 71 / 50 10 30 10 ASD 87 69 88 69 / 50 10 30 10 MSY 90 76 91 77 / 60 10 40 10 GPT 87 71 87 71 / 50 20 30 20 PQL 87 69 88 69 / 60 20 40 20 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...RW LONG TERM....RW AVIATION...RW MARINE...RW