Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
Issued by NWS New Orleans/Baton Rouge, LA
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595 FXUS64 KLIX 181508 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 1008 AM CDT Wed Sep 18 2024 ...New UPDATE... .UPDATE... Issued at 1005 AM CDT Wed Sep 18 2024 Forecast looks to be on track for this afternoon. Did make some minor adjustments to PoPs, blending the HRRR and NBM, to show chances for showers are looking more isolated than previously thought. 12z sounding is showing PWs starting to come down, 2" on last nights 00z sounding and 1.75" on this morning`s. HRL && .SHORT TERM... (Today through Thursday) Issued at 311 AM CDT Wed Sep 18 2024 The only thing that sort of defines this trough axis that has been very slow to move through is in PW values. 00z soundings show this drier air NE of the area with 1.4" PW at BMX and near 2" at LIX. Models show this boundary moving very slowing to the coast by late Thursday. This presents a very good environment for fog production along with abundant moist soils and rain that fell yesterday, moisture in the boundary layer is not lacking. There is a very nice susident dry layer at 955mb which will take the heat radiated from the sfc. Basically, we should see fog form again this morning, but unlike past mornings, this could be a bit more dense along and north of the interstate 10/12 corridor as well as some south shore locations mainly outside heat islands. And we should have clear skies through the morning hours until the cloud on the ground develops. We will watch for this as it should begin to form just before sunrise. We may need to issue a dense fog advisory if this becomes the case. With the boundary still to the NE of the area, we could still see at least isolated sh/ts around and there are some hints at where the best locations for higher precip numbers. We have brought precip chances up a bit from the NBM and also tried to give the highest numbers to the areas that look to have the highest potential for sh/ts with help from CAMS and synoptic scale models. Otherwise, by Thursday we should see somewhat lower precip numbers but may keep isolated along and ahead of this boundary as it lays along the coast late Thu. && .LONG TERM... (Thursday night through Tuesday) Issued at 311 AM CDT Wed Sep 18 2024 Conditions are still conducive for waterspouts today, but this begins to change as we move into late Thu into the weekend. We will have a few easterly waves that traverse the gulf late in the weekend into next week and this will at least enhance rain chances during that time frame. The large stacked high is beginning to move NE and will eventually center itself over southern TX by the weekend. The extended holds some very interesting features. The first is what will grab headlines which will be the area in the NW Caribbean that has a 20% chance of becoming a tropical cyclone over the next 7 days. The other is a very deep fast digging upper trough into the country as this tropical cyclone is supposed to start developing. This is what models are advertising to pick this tropical system up bringing it north then NE. The upper trough moves so fast that strong modifying is not able to take full effect. IF this tropical system moves east of the area, it could help bring this very dry cool air into the area. That is a big IF at the moment. We will have to see how this works out but at some point over the next month we should see the first true cold front move into or through the area. && .AVIATION... (12Z TAFS) Issued at 311 AM CDT Wed Sep 18 2024 IFR conditions via cigs and vis should be found at most if not all sites at least for a short time this morning with all sites moving to VFR by mid morning. Isolated to scattered TSRA will be around but may only be high enough to mention at GPT and MCB. && .MARINE... Issued at 311 AM CDT Wed Sep 18 2024 Winds will be quite light and variable at times over the next several days. But as we get to the weekend, winds become more stable and established from the east and rise to around 15kt. Winds and seas will be higher near and in storms and waterspouts will be possible with any of this activity into Thu. && .PRELIMINARY POINT TEMPS/POPS... MCB 88 70 89 67 / 30 30 0 0 BTR 92 74 93 71 / 0 0 10 0 ASD 89 73 91 70 / 10 0 10 0 MSY 89 74 89 74 / 10 0 10 0 GPT 86 72 89 70 / 30 10 0 0 PQL 91 72 93 70 / 30 20 0 0 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...TE LONG TERM....TE AVIATION...TE MARINE...TE