Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
Issued by NWS New Orleans/Baton Rouge, LA
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791 FXUS64 KLIX 240829 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 329 AM CDT Tue Sep 24 2024 ...NEW SHORT TERM, LONG TERM, MARINE... .SHORT TERM... (Today through Wednesday) Issued at 233 AM CDT Tue Sep 24 2024 A cold front currently resides basically from Texarkana northeast to the MO Bootheal this morning. This feature will continue to move closer to our region today as the parent upper level trough continues to spread eastward across the lower MS River Valley. This feature may be enough to produce some isolated to scattered shower activity across interior south Mississippi and perhaps over the Florida Parishes of Louisiana. However, QPF signal is modest given the upper level dry air. In fact, the special 06z sounding tonight showed this dry column very well...which again should limit a more widespread shower/storm potential today. The only other entity to mention this morning is perhaps some patchy fog in the lower spots, however, guidance may still be a bit too bullish with fog potential (as we`ve seen recently). The front is still just far enough away to limit low level moisture pooling, but there could be some localized patchy fog in those favored lower elevation spots. Prior to the front arrival and eventual passage sometime on Wednesday, we`ll still have to deal with above average temperatures across the region. Otherwise, for the remainder of the short term period eyes will shift to two primary synoptic features...1) the deepening upper level low across the Cornbelt...which eventually starts heading southward down the Mississippi River on Wednesday and 2) PTC9 over the western Caribbean and the impacts the upper level trough and closed ULL have on it. More about the evolution of those both in the long term sections. (Frye) && .LONG TERM... (Wednesday night through Monday) Issued at 233 AM CDT Tue Sep 24 2024 As PTC9 (forecast by this time to be a strong TS or hurricane) moves northward toward the Panhandle of Florida (quickly I may add) the 568dam H5 low will center over Arkansas. This will then take the TC north and eventually perhaps northwestward once it reaches the ENE or NE periphery of the ULL well inland. Being removed from the TC there will be a good bit of subsidence on the far outer periphery, which calls into question any POPs for this timeframe. At this juncture, decided to continue the ongoing forecast with consensus models, however, the QPF will contain a tight gradient if not from the subsidence surrounding the TC, from the dry slot the develops south of the cold core ULL over LZK or perhaps the ArkLaMiss region. Going into the weekend was a bit concerned about the cold temperatures aloft and any potential convection. With H5 temps approaching -20C across interior south Mississippi...any robust updraft could cause some hail potential. However, the QPF signal doesn`t support this neither does the remaining dry air residing over the forecast area. Decided to drop the prior 20 percent POPs respectively and went with a mostly dry weekend with comfortable mornings and around average or maybe a degree or two shy of average MaxTs. (Frye) && .AVIATION... (06Z TAFS) Issued at 1142 PM CDT Mon Sep 23 2024 VFR conditions in place this evening, and likely to be for much of the forecast period. Frontal boundary remains to the northwest of Louisiana. Potential does exist for patchy fog development around sunrise Tuesday, but only areas that I feel any confidence in mentioning are at KMCB and KHUM, and will mention brief MVFR to IFR visibilities there. If any fog does develop, it`ll improve quickly by mid morning. Only last day of only scattered cumulus on Tuesday before the front approaches overnight Tuesday night into Wednesday. Not expecting much in the way of convection prior to sunrise Wednesday, so there won`t be any mention in this package. (RW) && .MARINE... Issued at 233 AM CDT Tue Sep 24 2024 Mainly favorable marine conditions will give way to hazardous marine conditions by Wednesday as seas begin to build in response to PTC9 (then likely a TC) moving northward from the western portions of the Caribbean and southern Gulf of Mexico. Additionally, despite the building seas, gradient winds will also increase, which outside of wave heights, wind will also be the cause for SCAs for the Gulf Waters. Cautionary headlines for the tidal lakes look also possible respectively. By Friday, the storm will have moved well inland over Georgia...or points well east of our region. Seas will begin to relax then and especially going into the upcoming weekend. (Frye) && .PRELIMINARY POINT TEMPS/POPS... MCB 90 69 84 64 / 20 40 50 20 BTR 94 74 90 68 / 10 30 40 10 ASD 91 72 89 69 / 0 10 40 30 MSY 90 74 88 72 / 0 0 30 20 GPT 88 72 88 70 / 0 0 50 50 PQL 93 72 91 71 / 0 0 60 60 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...RDF LONG TERM....RDF AVIATION...RW MARINE...RDF