Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
Issued by NWS New Orleans/Baton Rouge, LA
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545 FXUS64 KLIX 201716 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 1216 PM CDT Mon May 20 2024 ...New AVIATION... .SHORT TERM... (Today through Wednesday Night) Issued at 303 AM CDT Mon May 20 2024 Strong and deep ridging will dominate the Gulf South through the entire short term period. The deep layer subsidence associated with this strong ridge axis will result in a very strong mid-level capping inversion remaining in place through Wednesday night. This will effectively suppress cloud development to below the inversion, and result in a dry forecast through the period. Beneath the inversion, Summer like heat and humidity will be on tap with highs easily warming into the upper 80s and lower 90s and lows only dipping into the upper 60s and lower 70s as dewpoints remain elevated on the back of sustained onshore flow. Overall, have opted to stick with NBM deterministic values for daytime highs as they were on the upper end of the probabilistic spectrum. However, deterministic lows were in line with the 25th percentile, and have opted to raise lows up to the 75th percentile to better reflect the high dewpoints in place. Additionally, high humidity at night will combine with clear skies and light winds to produce some patchy fog development during the overnight hours, especially for more inland areas. Overall, a very benign stretch of weather is expected through the short term with high pressure in place over the area. && .LONG TERM... (Tuesday night through Sunday) Issued at 303 AM CDT Mon May 20 2024 Going into Thursday, main focus will be on the ongoing warming trend as ridging remains parked over the southern US. Highs were not modified much from deterministic NBM forecast values, climbing into the mid 90`s possible late week into the Memorial Day Weekend which lies on the 75th percentile of the NBM ensemble envelope. Be aware, this does yield heat indicies crossing into the upper 90`s to low 100`s for many locations. While not excessive, could be strenuous to those spending time outdoors during the holiday weekend. With this being the first time in the year seeing highs and attendant heat indicies heat up this much, messaging will be focused for those to exercise caution spending time outdoors for extended periods. Also, kept the warmer bias in overnight lows going from the short-term into the long-term with warmer than average temperatures persisting. Additionally, not seeing much in the way of rain chances. Will make one small note about the quasi-zonal flow aloft. Seeing some deterministic runs hint at a few subtle shortwave impulses/PVA riding along the west to east mid-level flow. The response is a few MCS/thunderstorm complexes over Texas perhaps nosing into western Louisiana or into the NW Gulf. This will need to be watched, as any stronger cold-pool propagated complex (in conjunction with attendant weak PVA/forcing) could press more east than global guidance suggests (as global guidance typically struggles at convective allowing processes). Will monitor trends but for now, holding onto NBM values keeping it hot and mainly dry this upcoming weekend. Something to check back on. KLG && .AVIATION... (18Z TAFS) Issued at 1214 PM CDT Mon May 20 2024 Clear skies and light winds through the period will lead to no appreciable impacts for most terminals. Will have a similar setup as this morning on tomorrow morning with a shallow inversion aiding in light fog and low cloud development. A few terminals such as KMCB, KBTR, and KASD may see MVFR visibilities from the light fog. Otherwise, VFR will dominate the forecast. MEFFER && .MARINE... Issued at 303 AM CDT Mon May 20 2024 A fairly benign period of weather is expected over the coastal waters through the end of the week as a broad ridge of high pressure dominates the region. A persistent southeasterly wind of around 10 knots and relatively calm seas of 1 to 3 feet are expected through the end of the week. The high pressure system over the area will also keep thunderstorm development at bay, so no waterspout, lightning, or localized gusty winds are anticipated through Friday. Overall, a great week for boating activities is on tap. && .PRELIMINARY POINT TEMPS/POPS... MCB 68 88 68 88 / 0 0 0 0 BTR 70 92 72 92 / 0 0 0 0 ASD 72 89 72 89 / 0 0 0 0 MSY 74 89 75 89 / 0 0 0 0 GPT 73 86 74 87 / 0 0 0 0 PQL 71 89 71 89 / 0 0 0 0 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...PG LONG TERM....KLG AVIATION...ME MARINE...PG