Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
Issued by NWS New Orleans/Baton Rouge, LA
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837 FXUS64 KLIX 102325 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 625 PM CDT Mon Jun 10 2024 ...New AVIATION... .SHORT TERM... (This evening through Tuesday night) Issued at 336 PM CDT Mon Jun 10 2024 Upper trough extended from Maine to the Lower Ohio River Valley this afternoon, with upper lows over New Mexico and off the Baja California coast. At the surface, a frontal boundary was drifting southward, and may be fairly close to the Interstate 10/12 corridor. Scattered showers and a few thunderstorms dotted the area, with somewhat better areal coverage over the lower portions of the coastal parishes. Storms have really struggled to strengthen, with very few even reaching the -20C level, which was around 26,000 feet this morning. Wind fields below 600 mb were rather weak, and while we can see outflows apparent on radar, haven`t seen any ground truth wind reports much above 20 mph. Away from convection, temperatures were generally in the upper 80s to mid 90s at mid afternoon. Dew points were in the low to mid 70s near and south of the frontal boundary, but seeing dew points fall into the upper 60s across southwest Mississippi. Expect most or all of the weak convection currently on radar to dissipate as we lose surface heating this evening. The upper trough to our northeast should help the surface boundary off the coast. Drier air, defined in this case as sub 70 dew points, may not make it too far south of Lake Pontchartrain. Considering the slightly better moisture south of the lake, we may see isolated convection there tomorrow afternoon as we reach convective temperatures, but with little shear and sub optimal lapse rates, threat of severe at this time appears to be pretty low. Again tomorrow, storms should weaken as we lose surface heating. Won`t depart significantly from the NBM deterministic temperature forecast, which is pretty much a compromise on minimum temperatures, and on the warmer end for highs. && .LONG TERM... (Wednesday through Sunday night) Issued at 336 PM CDT Mon Jun 10 2024 Frontal boundary remains just offshore for the end of the workweek, with the airmass gradually drying out. By the time we get to Thursday/Friday, precipitable water values fall to about the 10th percentile climatologically, around 1.10 inches. With weak offshore flow, that should limit convection significantly. Can`t rule out one or two storms along sea breeze boundaries, but that is probably pushing things. Would not be surprised at all to see high temperatures in the mid and upper 90s (at least) across much of the area Thursday into Saturday, with very little inland penetration of sea breezes. NBM numbers are trending on the warmer end, and may even need to bump them up a degree or two in later packages. Highs on Sunday will be very dependent on precipitation trends, and don`t see that as a confident target of opportunity to diverge from the NBM solution. The center of an upper ridge is forecast to transit Interstate 40 to our north over the weekend. This places the local area under easterly mid and low level flow, but the global models are struggling with the details of how that may impact the local area. The GFS solution would paint a fairly wet Sunday for the Mississippi coast and eastern portions of southeast Louisiana, while the ECMWF keeps that area comparatively dry, and better rainfall to the west of the local area. Don`t have any real issues with the NBM PoPs of 40-60 percent on Sunday, but confidence in precipitation amounts is rather low. && .AVIATION... (00Z TAFS) Issued at 614 PM CDT Mon Jun 10 2024 Terminals will all be VFR for the forecast period outside of possible dips due to thunderstorms. The window for tonight is closing soon but cna`t rule out some storm impacting a terminal so left VCTS in a few terminals. Otherwise winds will generally be light and out of the northeast. -BL && .MARINE... Issued at 336 PM CDT Mon Jun 10 2024 Low level flow should become offshore overnight tonight, and remain primarily offshore until at least late Friday. Convection should be the only real concern over the next 48 hours or so, and that threat is fairly limited. Once onshore flow commences over the weekend, we may start building swell. Depending on which global solution becomes preferred, at least some potential for higher than normal tide levels. The relatively good news in that case is that astronomical tide levels will be decreasing this weekend. && .PRELIMINARY POINT TEMPS/POPS... MCB 68 89 65 89 / 10 10 0 10 BTR 74 93 71 93 / 10 20 0 20 ASD 73 93 70 93 / 20 20 10 20 MSY 78 92 77 92 / 10 40 10 30 GPT 74 92 72 92 / 20 10 10 10 PQL 71 95 69 94 / 20 10 10 10 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...RW LONG TERM....RW AVIATION...BL MARINE...RW