Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
Issued by NWS New Orleans/Baton Rouge, LA
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773 FXUS64 KLIX 102135 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 335 PM CST Sun Nov 10 2024 ...New SHORT TERM, LONG TERM, MARINE... .SHORT TERM... (This evening through Monday night) Issued at 325 PM CST Sun Nov 10 2024 Rafael is now a post tropical cyclone with the center mainly exposed. There has been one burst of convection to the south of Terrebonne Parish which produced gusts well in excess of 40 knots, but that cluster is propagating southward. That should pretty much end any significant threat of thunderstorms or heavy rainfall. Likely to still be some patches of light rain for the next 3-6 hours. Main forecast questions for the next 36 hours are whether there will be fog overnight tonight and how quickly the deeper dry air works into the area. We do expect some low ceilings and lowered visibilities if winds decouple overnight, but not confident on dense fog occurring, as there`s still enough of a gradient to keep things mixed. Forecast soundings for Monday morning really don`t indicate drier air getting much further east than Interstate 55. Areas south of Interstate 10 may not entirely clear out for the entire period of the short term ending 12z Tuesday morning, and could even see a little light precipitation tomorrow. Areas that see sunshine on Monday could get into the lower 80s, or even a shade warmer, but most of the area likely to remain in the 70s. && .LONG TERM... (Tuesday through Saturday night) Issued at 325 PM CST Sun Nov 10 2024 The next upper trough will move through the Mississippi River Valley Wednesday night with very moist air in advance of it. Showers and thunderstorms are likely ahead of the front Wednesday and Wednesday night, but that`s about the last thing the operational medium range models agree on. GFS 12z run (and the couple preceding that) never brings cooler and/or drier air into the area with temperatures running 10-15F above normal, even after the frontal passage. The ECMWF operational is 10-15F lower on overnight lows, dropping morning lows well into the 40s across the north half of the area Friday and Saturday mornings, with highs about 5 degrees cooler than the GFS. It should be noted that there is quite a bit of spread in the ECMWF ensemble for the end of the week, with the 90th percentile low temperatures still about 5 degrees cooler than the GFS deterministic. The NBM temperatures at the end of the week are a compromise, and would expect that there will be movement of those numbers in later packages, with the somewhat cooler solutions more reasonable. After all, it is mid- November. && .AVIATION... (18Z TAFS) Issued at 1141 AM CST Sun Nov 10 2024 Most terminals with MVFR conditions occasionally lowering to IFR briefly within patches of rain. Threat of TSRA is rather limited, and if it is going to occur, it`d be in the next 6 hours or so, with KHUM the favored terminal. MVFR conditions likely to lower to IFR at multiple terminals after sunset, even as any widespread precipitation ends. Potential for very low conditions exists after midnight tonight where winds decouple in the moist airmass. Favored terminals for this would be KMCB/KBTR and perhaps KHDC. Expect MVFR conditions to return at mid-morning Monday, and then perhaps VFR Monday afternoon. && .MARINE... Issued at 325 PM CST Sun Nov 10 2024 Convectively induced winds in our southwestern waters should slack off within the hour. Otherwise, winds are beginning to relax, with Small Craft Advisory over most of the inner waters replaced with Small Craft Exercise Caution headlines with forecast issuance, and the one over the outer waters replaced at mid-evening. We don`t have a lot of wave height reports over the open waters this afternoon, but working under the assumption that the seas are going to take somewhat longer to subside than the winds. Don`t expect that there will be a need to go much further than Monday morning with any headlines with this event. Right now, the wind forecast would indicate potential for Exercise Caution headlines with the mid-week front, as pressure gradient is well to the north of the area. && .PRELIMINARY POINT TEMPS/POPS... MCB 65 78 58 77 / 20 10 10 10 BTR 69 83 62 82 / 10 0 10 10 ASD 69 78 64 79 / 40 30 10 10 MSY 71 77 68 78 / 40 20 10 10 GPT 69 77 65 79 / 50 40 20 10 PQL 70 80 66 82 / 60 40 20 10 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...Coastal Flood Advisory from 9 PM this evening to 9 AM CST Monday for LAZ057-058-060-066>070-076>078-080-082-084-086-087. GM...Small Craft Advisory until 9 PM CST this evening for GMZ570-572- 575. MS...Coastal Flood Advisory from 9 PM this evening to 9 AM CST Monday for MSZ086. GM...Small Craft Advisory until 9 PM CST this evening for GMZ572-575. && $$ SHORT TERM...RW LONG TERM....RW AVIATION...RW MARINE...RW