FXUS64 KLIX 040535 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 1135 PM CST Tue Dec 3 2024 ...New AVIATION... .SHORT TERM... (This evening through Thursday night) Issued at 255 PM CST Tue Dec 3 2024 A fast moving southern stream upper level vorticity max sliding through the area tomorrow and Thursday will be the main feature influencing the forecast through the short term period. In advance of this upper level impulse, increasing southerly flow in the low to mid levels will help to transport deeper Gulf moisture back into the area. This is best reflected by PWATS rising from around half an inch tonight to between 1.5 and 1.75 inches by late Wednesday night and Thursday morning. These values are around the 90th percentile for this time of year. Fortunately, the rainfall is expected to remain light to moderate and occur over an extended period of time. This will limit the flood threat greatly even as storm total precipitation approaches 2 inches in a few locations. The southerly flow pattern will also lead to a quick warm up over the next 24 hours. Lows tonight will once again be chilly with lows falling into the lower to middle 30s along and north of the 10/12 corridor and the low to mid 40s further to the south. Highs will quickly rise into the 60s tomorrow afternoon, and overnight lows will only dip into the 50s tomorrow night. Thursday will see highs warm back into the 60s, but a cold front sweeping in from the north as the upper level vort max shifts to the east and a northern stream trough deepens over the eastern CONUS will quickly usher in a much colder and drier airmass by Thursday night. Lows will dive into the lower to middle 30s again for locations along and north of I-10/12, and the upper 30s and lower 40s further to the south. Fortunately, very dry air will also move into the area Thursday night and this will push PWATS down to around 0.50 to 0.75 inches or close to seasonal averages by late Thursday night. The end result is that precip chances will not align with the freezing temperatures over the northern third of the CWA as the deeper moisture is pushed back offshore. Overall, there is still a good deal of spread between various model solutions on the strength of the cold pool advecting into the area Thursday night. Have opted to trend a bit cooler than the NBM, and more toward the ECMWF solution as a strong and deep cold pool over the northern Plains and Canada remains in place. && .LONG TERM... (Friday through Monday night) Issued at 255 PM CST Tue Dec 3 2024 Continuing the trend of leaning more toward the ECMWF solution on Friday will lead to daytime highs running a few degrees cooler than the NBM with highs only warming into the lower 50s forecast for the entire region. This may even be too warm as the ECMWF keeps readings into the upper 40s. Friday night will also be very cold as a surface high becomes a bit more centered over the region resulting in lighter winds. Lows will easily fall back to the same levels seen the night before. Fortunately, conditions will remain dry through this period as PWATS linger around 0.75 inches. Temperatures will begin to modify over the weekend as high pressure shifts to the east and a potent southern stream trough moves into the southern Plains. Increasing deep layer southerly flow will once again usher in a warmer and more moist airmass with PWATS increasing to between the 75th and 90th percentile climatologically for this time of year, and temperatures warming into the lower 70s by Sunday afternoon. These above average conditions will continue into Monday and Monday night as deep layer southerly flow persists. The approaching southern stream trough axis and more favorable jet dynamics will induce a broad region of increasing upper level lift, and this lift will tap into a modest amount of instability to produce periods of rain with embedded thunderstorm activity. This is reflected by likely PoP forecast for Sunday night and Monday as the trough axis begins to move into the area. Sounding profiles are not very supportive of severe storms at this time for early next week, but this will continue to be monitored as the evolution of the southern stream trough comes into better focus. && .AVIATION... (06Z TAFS) Issued at 1131 PM CST Tue Dec 3 2024 VFR conditions with light/variable winds expected to persist through the next 12 hours. Mid level clouds will be moving in from the west before noon. As the day progress, light to occasionally moderate rain will spread east across Louisiana and Mississippi. && .MARINE... Issued at 255 PM CST Tue Dec 3 2024 Continued cold air advection over the waters tonight will keep winds elevated for the waters west of the Mississippi River through the overnight hours. These stronger offshore winds of 15 to 20 knots will keep exercise caution wording in the forecast. By tomorrow, a surface high pressure system will become more centered over the area, and this will allow winds and seas to fall below headline levels from tomorrow through Thursday afternoon. However, another strong cold front will sweep through the waters Thursday night in the wake of a passing low, and winds will rise back into advisory levels from late Thursday night through Friday night. As another high moves through the Deep South on Saturday and Sunday, winds will turn more easterly and also fall into the 10 to 15 knot range. Seas will also ease from 5 to 7 feet offshore Saturday morning to to 3 to 5 feet by Sunday. && .PRELIMINARY POINT TEMPS/POPS... MCB 32 63 52 59 / 0 50 100 70 BTR 39 67 56 63 / 0 50 90 70 ASD 35 67 56 65 / 0 20 80 80 MSY 46 68 60 66 / 0 20 70 80 GPT 38 66 57 66 / 0 10 70 70 PQL 32 66 55 66 / 0 0 60 80 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...PG LONG TERM....PG AVIATION...ME MARINE...PG