Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
Issued by NWS New Orleans/Baton Rouge, LA
084 FXUS64 KLIX 022323 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 623 PM CDT Tue Sep 2 2025 ...New AVIATION... .SHORT TERM... (Tonight through Thursday night) Issued at 1220 PM CDT Tue Sep 2 2025 The models remain in good agreement on the timing of a stronger upper trough embedded within deep layer northwest flow aloft. This lends to higher confidence that a much drier and more stable airmass will be in place by Wednesday night in the wake of this passing system. In advance of this trough, moisture will remain very limited with PWATS running between the 25th percentile and median values for this time of year. This will keep rain chances suppressed at 20 percent or less for locations north of coastal Louisiana through tomorrow afternoon. However, along the immediate coast of Louisiana, a weak stationary boundary will continue to serve as a focus for widely scattered convective activity and low end chance PoP of around 30 percent through this evening. Once the trough and associated front passes by, very low PWATS in the 25th percentile range will be in place through Thursday night across the entire area as deep layer subsidence and negative vorticity advection takes hold. The front will also sweep far enough offshore to suppress convection even across the coastal waters. Although conditions will be mainly clear and dry, the cooler airmass to the north will not feed down into the Gulf South. As a result, temperatures will actually warm a few degrees above normal in the mid 90s on Thursday as the drier air quickly heats beneath strong solar insolation. Fortunately, low dewpoints and humidity will keep maximum heat index values in the upper 90s. && .LONG TERM... (Friday through Monday night) Issued at 1220 PM CDT Tue Sep 2 2025 The pattern aloft will begin to transition from the persistent trough that has dominated the eastern half of the CONUS for the past couple of weeks to a more zonal flow regime as the trough weakens and lifts to the north and east. Initially, the region will still be under of the trough on Friday, but over the weekend the zonal flow pattern will become predominant. Heading into early next week, the remnant energy from a Pacific based tropical feature that is projected to move through the Baja California region will move into the Southern Plains. Both the GFS and the ECMWF have come into somewhat better agreement on this occurring, bu the GFS has a much stronger and deeper feature forming over the Plains on Monday. Given these disparities in strength, a blended solution using the national blend of models was used for the Monday and Monday night forecast. In the low levels, a surface ridge will be parked over the area on Friday, but will begin to shift to the east over the weekend and early next week. This will allow the wind field to shift from offshore to onshore by the weekend. These persistent onshore winds will gradually usher in more moisture and PWATS will climb from below the 25th percentile on Friday and Saturday to as high as the 90th percentile or 2.1 inches by Monday. In terms of the sensible weather impacts from these shifting patterns, will keep conditions warm and dry on Friday and Saturday with largely clear skies, very low PoP of less than 20 percent, and warmer than average temperatures in the mid 90s. Fortunately, the dry air will continue to mitigate heat indices with max values peaking near 100 degrees both days. As the moisture deepens on Sunday and Monday, cloud development and overall rain chances will start to increase. PoP on Sunday will see a decent moisture gradient over the area, with scattered convection south of I-10 and more isolated activity further inland. The increased in moisture,convection, and cloud cover will also allow temperatures to fall back to near average in the upper 80s and lower 90s. Similar conditions are expected on Monday, but rain coverage should be slightly higher as forcing aloft increases with the deepening trough to the west and PWATS climb to somewhere between the 75th and 90th percentile. && .AVIATION... (00Z TAFS) Issued at 617 PM CDT Tue Sep 2 2025 Generally VFR conditions expected through the forecast period. If there`s going to be any precipitation impacting a terminal, it would be KMCB tomorrow afternoon. At this point, the probability is too low to justify a mention in the TAF forecast. && .MARINE... Issued at 1220 PM CDT Tue Sep 2 2025 Overall, no major impacts to maritime operations are expected through the weekend. Through tonight, a weak frontal boundary will remain stalled along the coast of Louisiana. Scattered thunderstorm activity and east winds of 10 to 15 knots are expected over the offshore waters with this boundary in place. Tomorrow into tomorrow night, a much stronger front will push through the waters and winds will shift to the north. A drier surface high will then settle in for Thursday and Friday with very low rain chances, light winds, and calm seas. This high will begin to move to the east on Saturday allowing for a light southerly flow to develop. Offshore shower and thunderstorm activity will also increase as moisture feeds back into the area over the weekend. && .PRELIMINARY POINT TEMPS/POPS... MCB 68 89 69 92 / 10 20 10 0 BTR 71 90 72 93 / 10 20 10 0 ASD 67 90 70 91 / 0 10 0 0 MSY 75 90 75 91 / 10 10 0 0 GPT 70 88 71 88 / 0 0 0 0 PQL 67 89 69 89 / 0 0 0 0 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...PG LONG TERM....PG AVIATION...RW MARINE...PG