Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
Issued by NWS New Orleans/Baton Rouge, LA
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252 FXUS64 KLIX 032048 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 348 PM CDT Mon Jun 3 2024 ...New SHORT TERM, LONG TERM, MARINE... .SHORT TERM... (This evening through Tuesday night) Issued at 335 PM CDT Mon Jun 3 2024 Upper pattern is a bit west-northwesterly across the area with a shortwave to the northwest across Kansas, and a stronger trough across the Pacific Northwest. Isolated precipitation tried to develop around 18z, but with low level flow from the south and upper flow from the northwest, it appears that shear has stopped most or all of the updrafts from becoming deep up to this point. Temperatures at 3 PM CDT were generally in the upper 80s with dew points in the lower and middle 70s. Main concerns over the next 36 hours will be the potential for mesoscale convective systems to the northwest of the area to travel southeastward and reach the area. One such area is currently over Kansas. Most guidance dissipates this complex during the evening, but the runs of the HRRR since 12z bring it pretty close to the CWA before dissipating it around midnight. While we currently aren`t carrying precipitation mention across southwest Mississippi late this evening, threat is not zero. A somewhat more significant threat appears to be possibly shaping up for the afternoon hours tomorrow, as a second complex is forecast to develop over Oklahoma after midnight tonight and follow much of the same track southeastward. While most guidance doesn`t indicate this system reaching the area tomorrow, the recent runs of the HRRR have it reaching the area around midday tomorrow, and this does have the support of the ECMWF operational model. Forecast soundings from the GFS do show potential for the cap to be broken with CAPE values exceeding 3000 J/kg, low level lapse rates of 7.5 to 8C/km and DCAPE values exceeding 1300 across northern portions of the area. SPC on their midday Day 2 update spread the Marginal Risk into our area, and can`t really discount it. So, we will continue carrying thunderstorm chances for tomorrow across the area, although the GFS/NAM solutions argue dry. The HRRR solution has it through the CWA by about 02z Wednesday, but tends to be a bit slow, especially if it becomes cold pool dominant, so a dry forecast for Tuesday night isn`t totally unreasonable. Don`t see much need to diverge much from NBM temperature numbers, although might nudge overnight lows up a bit based on verification. && .LONG TERM... (Wednesday through Sunday night) Issued at 335 PM CDT Mon Jun 3 2024 As has been the case for the last week or more, ridging to the west of the local area and troughing to the east, global models have struggled to agree. Timing of shortwaves and/or convective complexes lead to a low confidence in details. The operational ECMWF is the wetter solution for Wednesday and Thursday, then dries out for the weekend. The operational GFS is comparatively dry for Wednesday and Thursday, then becomes the wetter model for the weekend. The current NBM deterministic numbers trend toward the ECMWF solution, but it is not a high confidence forecast at this time. Until a definitive trend regarding precipitation chances becomes apparent, can`t see making large changes in the NBM deterministic temperature forecast. && .AVIATION... (18Z TAFS) Issued at 1226 PM CDT Mon Jun 3 2024 Fairly well developed cumulus field this afternoon may occasionally produce ceilings near FL025 or FL030. Cloud streets are moving northward, and radar echoes are primarily north and east of a low level convergence boundary extending from near KMOB to the north-northwest across extreme eastern MS. Will carry VCTS at the western terminals (KBTR, KMCB, KHDC, KHUM) this afternoon, but the threat is non-zero elsewhere. Any convection that develops should dissipate toward sunset. Some concern about additional convection as at least a few CAMs bring mesoscale convective complexes southeastward late this evening and again during the day on Tuesday. The models showing one this evening would mainly impact KMCB, with the 2nd on Tuesday afternoon potentially impacting most terminals. At this time, confidence in those solutions is much too low to include in forecast at this time. Any flight restrictions below MVFR overnight would primarily be at KMCB, where IFR ceilings are possible. Any restrictions should improve by mid-morning Tuesday. && .MARINE... Issued at 335 PM CDT Mon Jun 3 2024 Main marine concern over the next few days is likely to be the potential for thunderstorms, with one such period possible tomorrow afternoon. Confidence in timing is fairly low. There could be brief periods where Small Craft Exercise Caution headlines are necessary. One would be around sunrise tomorrow over the western waters. That one is rather borderline, so we`ll let the evening shift take a look at that one before a final decision. && .PRELIMINARY POINT TEMPS/POPS... MCB 70 89 71 90 / 20 40 0 40 BTR 76 93 76 94 / 10 30 0 30 ASD 75 91 75 93 / 10 40 0 30 MSY 77 90 77 92 / 10 30 0 30 GPT 77 88 77 89 / 20 40 10 30 PQL 74 90 75 91 / 20 30 0 20 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...RW LONG TERM....RW AVIATION...RW MARINE...RW