Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
Issued by NWS New Orleans/Baton Rouge, LA
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781 FXUS64 KLIX 301754 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 1254 PM CDT Thu May 30 2024 ...New AVIATION... .SHORT TERM... (Today through Friday) Issued at 321 AM CDT Thu May 30 2024 The old front has backed off into central Miss which is where some sh/ts are developing this morning. A few storms are moving NE as they follow this boundary north of Natchez and this area through central Miss should continue to fester until after sunrise. The MCS that moved offshore of Cameron Parish this morning is following a ThetaE gradient to the SE. This gradient will hang around today and will set up from south of New Orleans to Lafayette up to Shreveport. This will be the second area that sh/ts will develop today. Most activity today will be the more normal summer type pop up storms. The late afternoon/evening activity is being advertised to move into the area again with models trying to indicate the MCS over the northern TX panhandle running along the old frontal boundary then dividing as one area moves along the front and another moving along the ThetaE axis. Some models try to keep this whole thing together, but this would be unusual and some just keep this MCS moving along the Red River Valley then dissipate it after sunset today. Regardless of which way this goes, any activity that decays west of the area could and most likely would cause new storms to develop downstream in our area and if they actually make it in tact, we would still get some storms with it. The fcast will reflect this outcome for today with scattered storms over about 2/3rds of the area. This pattern does not change a lot for Fri, but some subtle differences are shown. The old front well to the north will buckle into Oklahoma where a sfc low will develop early Fri and move east. This should be the main corridor for most storms to develop and travel Fri. The ThetaE gradient will still be located over the area near New Orleans except it will also buckle northward from just west of BTR to Monroe starting tonight. This will actually produce a barrier- like feature causing anything that makes it east of this line to begin decaying, but moving into this drier air mass could produce some strong wind speeds. That being said, downburst numbers are basically nonexistent today and tomorrow. And the best numbers for severe storms will be over and west of BTR and along and west of a BTR to MCB line Fri. Synoptic models are promising a run away squall line moving out of NW TX tonight into Fri morning. If this were to occur, it would look menacing but should not hold together very long as it moves across LA especially once it encounters this boundary/barrier. Storms look to develop over the NW/NC gulf Fri and move north along this barrier between BTR and LFT to join the sfc low and new front that will be pushing through the central plains. Other than this activity possibly moving over the western most portion of the area Fri, that would be about it outside a renegade pop up. && .LONG TERM... (Friday night through Wednesday) Issued at 321 AM CDT Thu May 30 2024 As the sfc low ejects to the NE it will cause the deep moisture field to also spread east(moving our barrier east) setting up new gradients. The "barrier" gradient looks to be found from west of Tallahassee northward well into central Tennessee then joining the sfc low to the north. The next gradient forms from SE Oklahoma to BTR to NEW. These two avenues are also where most of the sh/ts develop and travel except most storms with the eastern boundary should be moving north bound unless cold pools can propagate storms southward, while the western boundary would still be the MCS path to the SE bringing our rain chances higher Sat. After Sat, it is quite difficult to have enough confidence in any particular outcome. But global models are causing the entire gulf south flow to move gradients and boundaries northward as another cold front moves southward out of Canada. We should see the first glimpse of this late Monday as it moves into the northern tier of states. This is advertised to be close to the area by late Thu and into the gulf before stalling late Fri or early Sat of next week. Yes, we are far away for any strength of forecasting but when all global models agree on the same solution for systems in the westerlies, it does make one take notice. But we do need to factor in the time of year and that most of these systems stall before getting here or over the area. We will need to wait and see. && .AVIATION... (18Z TAFS) Issued at 1244 PM CDT Thu May 30 2024 Numerous thunderstorms have developed at all terminals near Lake Pontchartrain. Storm motions will be erratic in nature with dozens of outflow boundaries moving across the region through the next several hours. LIFR visibilities from these storms should be relatively short term but IFR/MVFR ceilings will likely last longer. VFR conditions will return 01-02Z as storms dissipated with loss of daytime heating. After a night of light/variable winds, expect moderate southeasterly flow with gusts 15-20kts by mid morning Friday. MEFFER && .MARINE... Issued at 321 AM CDT Thu May 30 2024 A very normal summer pattern is setting up over the northern gulf which is an onshore flow as fronts or troughs stall well inland. The fcast will reflect this as southerly winds of 10-15kt will remain over all waters into the new week. Any storms that are capable of developing or moving offshore will be able to produce erratic and much higher wind speeds. && .PRELIMINARY POINT TEMPS/POPS... MCB 67 86 68 85 / 20 30 30 70 BTR 73 89 73 88 / 20 60 20 70 ASD 72 89 74 88 / 10 30 20 70 MSY 76 88 76 88 / 10 40 20 60 GPT 73 88 75 87 / 10 20 20 70 PQL 69 91 73 88 / 10 10 20 60 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...TE LONG TERM....TE AVIATION...ME MARINE...TE