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479 FXUS64 KLIX 261007AFDLIXArea Forecast DiscussionNational Weather Service New Orleans LA407 AM CST Tue Nov 26 2024...New SHORT TERM, LONG TERM, AVIATION, MARINE....SHORT TERM...(Today through Wednesday)Issued at 401 AM CST Tue Nov 26 2024Lots of dynamic processes going on this morning. Having a lot of dynamic processes does not mean severe storms will break out, that is just one of the things we discuss and is also different than what is occurring this morning. Forcing at the sfc is quite high but the mid/upper high behind this cold front is bridging the southern end of it as the upper low and attendant trough are lifting out leaving the front behind. As the upper level flow becomes more parallel in orientation to the front, the front will slow with time and stall over the northern gulf this morning. The front can actually be seen very well in 14-11.2um sat imagery as a rope cloud moving through. The reason for the rope cloud and no storms is the layer just above the front is strongly compressive as the high moves in faster than the front at around 850mb. This subsident inversion will move down to around 900mb before it stops. we should also see the frontal inversion somewhere between 1000 and 850mb as it will have passed by the 12z flight. These different processes are very dynamic but not with those variables supportive of severe wx. This just leads to some light showers but no storms. Cloudy day in store as this front stalls and begins to lift back to the north as a warm front by this evening. This is when the fcast gets interesting from a fog standpoint for late tonight/Wed morning. Models are all in agreement with some type of strat deck moving in during the evening. But they are all having trouble with the height of this deck. Some are at the sfc(NBM & CONSShort) and others(all others) are bringing this in as a strat deck at different levels with the main level seen around 12-1500ft. This does make us confident in a strat deck developing and moving in, but we will need to see the level this deck comes in at. If it can come in above 1kft, the probability of it sitting down to the sfc is small. But if it comes in <=1kft, the probabilities are higher. Basically, the lower this deck moves in the higher the prob of it becoming fog. The conditions needed for "set down" is a very strong dry subsident layer just above the strat deck, which we will have and no cloud decks above that, which some of the area will have/not have. There is some evidence of a deck hanging out around 3-4kft for areas to the SE part of the CWA but none over the NW two thirds of the area. This is the area we will show some reduction in vis at this time since probs will be highest in these areas. But again, we will need to see the level at which this deck moves in. I guess, it could make it easy on us and just come in at the sfc and call it a day. But we all know nothing is that easy in meteorology.&&.LONG TERM...(Wednesday night through Monday)Issued at 401 AM CST Tue Nov 26 2024The next front should be closing in on the area around sunrise Thu. to visit looks to do so by Thu. There will be a strong thermal gradient with this front, so those locations that is passes during the day will begin to lower their temps through the rest of the day. Most areas should get a few showers with this. And this should bve the main convective unit. There is the potential for a few elevated storms, but severe is looking more and more as a non-player. Upper winds are oriented across the frontal boundary to support layer lifting(isentropic lift). At the moment, solutions are centered around this front clearing the area with some cloudiness and light showers left for the day and possibly night Thu. We could see some clearing skies by Fri as high pressure settles in. This will hold through the weekend and possibly into the middle of next week before return flow starts again.&&.AVIATION...(12Z TAFS)Issued at 401 AM CST Tue Nov 26 2024Cigs will lift from IFR to MVFR by mid to late morning after each terminal has fropa this morning. The front will move back over the area tonight bringing MVFR then IFR cigs with through the night. Winds will shift but will be weak as the front passes each time. We have kept vis in MVFR for now at most sites some along the coast at VFR for vis. But this will be looked at further as the VFR vis should move to at least MVFR but lower vis is possible tonight. &&.MARINE...Issued at 401 AM CST Tue Nov 26 2024A cold front is moving into the northern gulf waters this morning and will slow to a stall later this morning. This will bring a temporary wind shift from SE to N early today before the front moves back north tonight shifting these wind back to southerly. These winds are expected to be light around 10kt but some gusts could reach as high as 20kt. The next front is expected during the day Thu which should clear the northern gulf with much stronger northerly winds and cold temps.&&.PRELIMINARY POINT TEMPS/POPS...MCB 66 48 74 59 / 0 0 10 50 BTR 73 54 80 64 / 0 0 0 30 ASD 73 53 77 63 / 10 0 0 20 MSY 72 59 78 65 / 20 0 0 20 GPT 72 54 74 64 / 30 0 0 20 PQL 76 52 79 64 / 30 0 0 20 &&.LIX WATCHES/WARNINGS/ADVISORIES...LA...None.GM...None.MS...None.GM...None.&&$$SHORT TERM...TELONG TERM....TEAVIATION...TEMARINE...TE
