Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
Issued by NWS New Orleans/Baton Rouge, LA
258 FXUS64 KLIX 180415 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 1115 PM CDT Sun Aug 17 2025 ...New SHORT TERM, LONG TERM, AVIATION, MARINE... .SHORT TERM... (Today through Wednesday Night) Issued at 1051 PM CDT Sun Aug 17 2025 Persistence is the name of the game through the short term period as a broad upper level ridge axis centered over Texas and southern Plains continues to dominate the Gulf South. A pool of drier air in the mid-levels feeding on the back of a deep northerly flow regime will keep rain chances a bit lower and temperatures a bit warmer through Wednesday. The drier air is easily reflected by near to slightly below average PWATS for this time of year. The main impact will be a delayed convective initiation time frame with most of the thunderstorm activity not firing up until the mid to late afternoon hours each day. This will allow highs to quickly climb into the mid to upper 90s each afternoon. Fortunately, just enough dry air should mix down into the boundary layer to push dewpoints into the low to mid 70s by the afternoon hours when the hottest temperatures occur. This should keep heat index values generally between 105 and 108 or just below heat advisory levels. A heat advisory has not been issued for Monday, but anyone working outside should take their proper heat precautions including drinking plenty of water and taking breaks in the shade or indoors. Rain chances will generally range from 30 to 40 percent each day with the highest chances in the late afternoon hours. Fortunately, severe storms are not anticipated, but a few stronger storms producing winds of around 40 mph and heavy downpours could develop. Storm motion will be relatively slow at 10 mph or less, so heavier rainfall could produce some localized street flooding in poorly drained areas. Overall, though, the thunderstorm activity expected is pretty typical for this time of year in terms of intensity and coverage. && .LONG TERM... (Thursday through Sunday Night) Issued at 1051 PM CDT Sun Aug 17 2025 All of the guidance continues to be in good agreement that the ridge will retreat to the west as a broad trough forms across the eastern third of the CONUS. Hurricane Erin off the eastern seaboard will assist in driving this trough a bit further south from Friday through the weekend. An associated weak frontal boundary will also slip into the area, and could stall over the region by the weekend. The biggest impact from this trough and boundary over the area will be a substantial increase in deep layer moisture and higher rain chances each day. PWATS will surge to between the 75th and 90th percentile, or between 1.9 and 2.1 inches, over this period. This moisture will tap into the broad area of increased forcing aloft along the trough axis to produce more numerous showers and thunderstorms each day. The thunderstorm activity will also start earlier in the morning as the convective temperature falls into the upper 80s. The end result will be a cooler and rainier pattern for the latter half of the workweek and into the weekend. Storm motion will remain slow and rainfall processes will be very efficient, so some localized flooding in low lying and poorly drained areas will be a growing concern by the weekend. There may also be a few convective complexes that slide down from the Arklatex region over this period, so that will need to monitored for additional flooding concerns. && .AVIATION... (06Z TAFS) Issued at 1051 PM CDT Sun Aug 17 2025 Prevailing VFR conditions will be the rule at all of the terminals through the forecast period. However, another round of widely scattered storms could form generally after 18z as temperatures climb back into the mid to upper 90s. This convective threat for the afternoon hours is reflected by additional PROB30 wording at most of the terminals. PG && .MARINE... Issued at 1051 PM CDT Sun Aug 17 2025 The Summer doldrums continue across the coastal waters as light winds of less than 10 knots and seas of around 1 foot persist through the end of the week. Thunderstorm chances will be lower than average through Wednesday as some drier air and more northerly winds persist, but higher thunderstorm chances take hold to close out the week. Outside of the locally higher winds and waves associated with any thunderstorms that form, there are no significant impacts to maritime activities expected through the end of the week. && .PRELIMINARY POINT TEMPS/POPS... MCB 74 96 73 96 / 20 30 20 30 BTR 75 96 75 95 / 20 50 30 40 ASD 75 95 74 95 / 20 30 10 30 MSY 80 94 79 93 / 20 40 20 40 GPT 77 92 76 92 / 20 20 10 30 PQL 75 93 75 92 / 10 20 10 30 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...PG LONG TERM....PG AVIATION...PG MARINE...PG