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857 FXUS64 KLIX 051143AFDLIXArea Forecast DiscussionNational Weather Service New Orleans LA543 AM CST Sun Jan 5 2025...New SHORT TERM, LONG TERM, AVIATION, MARINE....SHORT TERM...(Today through Tuesday) Issued at 539 AM CST Sun Jan 5 2025Quite the noisy forecast package tonight. A plethora of impacts expected over the next 48-72 hours. First is the threat of strong to severe storms along with strong gradient winds. Next will be cold conditions with wind chill readings as low as the mid teens tomorrow morning and then the next few days morning lows will be below freezing for most of the area with some locations in the lower 20s. BLUF...- Slight Risk for severe weather across much of the area along and north of the 10 corridor along with Pearl River and Hancock counties in MS. A Marginal Risk is highlighted for the rest of the area. - Winds advisory for the entire area from noon till midnight mainly for wind gusts at or just above 40 mph. - Cold Weather Advisory in effect from midnight tonight to 15z Monday. For areas mainly along and northwest of a line from Montegut, LA to New Orleans to Pascagoula, MS. Wind chill readings could be in the mid teens across southwest MS and adjacent LA parishes and in the lower to mid 20s across portions of the southshore. - Small Craft Advisory still in effect for all coastal zones till 12z Tuesday. Some of the open waters may need a Gale Warning after the cold front passes late tonight. --- No Freeze Warnings are out yet as the colder morning lows will be Tuesday and Wednesday morning. One other note is temperatures will fall below freezing for a good chunk of the region but given that the temperatures will not fall cold enough to lead to a risk of pipes bursting the greater threat is the Cold on people and pets, thus the Cold Weather Advisory (CWY) takes precedence over a light freeze and will be the only cold/freeze product issued tonight. Over the next few nights there may be a mix of Cold/Freeze products depending on location but these products will "NOT" overlap (issued for the same area for the same time frame). For additional information on the new cold weather products please refer to weather.gov/lix/ColdWeatherChange2024. ---Today will be the last day for the next week we see temperatures above 60 and most won't get above 50 till Friday. Our sfc low continue to take shape and has moved into central OK. The main cold front is still surging down the lee side of the Rockies and has just pushed south through the TX panhandle. Strong WAA will cause the sfc low to push towards the Ozarks and southern MO by midday today. The s/w culprit is currently along the CO/KS/OK/TX borders with the mid lvl jet square in the base of the s/w. Until the core or even bulk of the mid lvl jet can start to get downstream of the trough axis this disturbance will continue to push east instead of northeast. There is still quite a bit of wind on the backside of the s/w and that will keep it from gaining much latitude for now but this s/w has likely dug as far south as it is going to. As it moves east towards the Ozarks and Mid Ms Valley this afternoon and tonight it will begin to provide broad lift across the region today. The sfc low will also help to pull the warm front north. At 9z it was draped from near the mouth of the MS river to the northwest into central OK so we are already starting to see it move north and dewpoints recovering. We also have WAA/isentropic lift showers impacting much of the area along and east of the I-55 corridor. This suggest that we will move into and remain in the warm sector most of the day. With dewpoints already in the lower to even mid 60s along the coast we should see mid 60s dewpoints north of I-12 by midday. Any breaks in the clouds today will lead to additional heating and that will increase the instability across the area. With highs forecast to be in the 70s and we will have some instability in place...sfc based CAPE 800-1500 j/kg. At the same time winds will begin to ramp up as the sun comes up helping to promote a little mixing. This will lead to wind gusts approaching 40 mph at times and thus the Wind Adv. Shear and instability will be in place during the day but we will need some sort of focused forcing with only broad lift increasing from slowly falling hghts and slowly increasing mid lvl winds. Given that, once the current shower activity pushes north and east of the area we may only see isolated to widely scattered activity through the afternoon. If we can get a few thunderstorms to develop around midday and early afternoon we will need to monitor them closely as they will likely be rotating. Heading into the late afternoon and evening hours things may get a little more bumpy. As our system finally pushes east into the Mid MS Valley with the cold front quickly surging into the Lower MS Valley. A line of storms is expected to develop along the front across northwestern LA and slowly expand south down the front as it moves east. The line is expected to be strong to severe. There will be a rather strong mid lvl punch with h5 winds 70 to 90 kts. H85 winds will respond as well with a strong LL jet developing across northeast LA and into northern MS. That said the best dynamics and kinematics will remain just off to our north and northwest. The location with the best combination of lift, forcing, instability, and shear will be southwest MS and the adjacent LA parishes along and east of I-55. A key thing to watch will be if the line can quickly consolidate into a line and not remain a broken squall line. A more solid line would promote cold pooling and that would cause it to surge east faster. That would be a double edged sword though. First it would likely move the line into our northwest late this afternoon or early this evening when we still have a decent bit of instability to work with. On the other hand the faster that line drives east the more it will move away from its support and then weaken. As mentioned earlier SPC still has the Slight Risk in place and the Enhanced to our north and northwest. This still looks good as the best combination of ingredients and timing will be just outside of our area.The line should quickly begin to lose its punch by the time it approaches I-55. The cold front will continue to quickly swing through the area and then CAA will begin along with strong northwesterly winds. Temperatures will drop very quickly first across the northwest and then southeast through the early morning hours. The CAA will be strong enough that the northwestern half of the CWA will likely see temperatures drop below 32 degrees before sunrise. Combine that with strong winds and even locations with the temperatures only falling into the mid to upper 30s will see min wind chill values below 25 degrees for a few hours tomorrow morning. Southwest MS and the FL parishes will likely see wind chill values drop into the teens. Because of these values we have issued a Cold Weather Advisory for most of the area. The only reason some locations aren't in the Cold Weather Adv is because the temperatures won't have dropped enough before sunrise and/or the winds will be just a touch weaker. This is Lower Jefferson, Plaquemines, and St Bernard parishes. The reason Orleans is in it is because the winds coming directly off the lake will be much stronger and thus lead to a slightly colder wind chill. Gusty northwest or northerly winds Monday will keep the CAA going and even as we start to clear out temperatures will struggle mightily to rise much. Highs area expected to mostly range from the lower to mid 40s. This will provide a chilly jumping off point for Monday night with the coldest morning of the season so far expected Tuesday morning. At this time most of the area is expected to drop to or below freezing with lows in the lower to mid 20s and and north of I-12 and across coastal MS. The problem is winds will still not shut down with the sfc high well off to our north and weak CAA still occurring. With these temps expected even a wind of 5-10 mph will make it feel a good bit colder and thus another Cold Weather Adv is expected Monday night. If the wind is a little weaker along and south of I-10 then we may have a Freeze Warning instead. /CAB/&&.LONG TERM...(Tuesday night through Saturday) Issued at 539 AM CST Sun Jan 5 2025The extended forecast is not getting any easier and the models continue to struggle with timing, placement, track, and strength of the system during the second half of the work week. The GFS actually appears to be a good compromise as it has a little more support from the ENS and GFES. The Op ECMWF appears to be a slightnorthern outlier and the GEM is the colder farther south outlier.This does not provide a lot of confidence in the forecast, especially with respect to any winter weather that said the trend over the last few days has been less and less optimistic about much if any in the way of winter weather. With that the NBM does have a good mix and is a decent middle road to take at this time. This does provide some strong wind gusts this afternoon around 40 mph at times but as we mix out we will lose some of the directional shear.Tuesday and through the work week many things will be high determined on how the mid lvl pattern evolves. The next disturbance coming out of the Pac will move onshore Monday and dig. As this feature digs the L/W trough will sharpen once again and at the base start to close off as it approaches the Baja region. On Thursday is when things begin to get a little interesting. If this system hangs back over the baja and even tries to cutoff it will likely lead to a sfc low develop a little farther south either just along the LA coast or even a little more south into the Gulf. If additional energy come down the backside of the trough keeping the low from cutting off and bringing the trough back into phase it should be a little more progressive with a slightly farther north sfc low...inland and moving across the area. The trend had been a little more north each day but that has stopped somewhat. A farther north track removes the threat of winter weather for our area while a farther south track keeps that possibility in play. In addition a faster solution likely taps into the cold air more where as a slower solution would allow us to moderate a little more unless there was another cold airmass already working south. Lets get this out now...the forecast will explicitly show a small window for a winter mix, SN, IP (sleet), FZ (freezing rain), and rain Thursday morning. That said if this current forecast is absolutely right then this will be very short lived and should provide little to no impacts (don't get too excited yet). What will happen is as we see moisture and lift increase precipitation will begin to develop and as it falls into the much drier air in the LL we will likely see some mix of frozen precipitation across northwestern sections of the CWA. But this will transition to all liquid rather quickly and there is a good chance that is you are not outside during the first 10-30 mins it is occurring then you won't see anything. Again this is if this is a perfect forecast and we all know that the likelihood of EVERYTHING going exactly as shown, especially 4-5 days out is a highly unlikely scenario. That said it is still way to early to rule out any chance of winter precip but the chance of that continues to fall and if we see any it would be very light at the beginning before we transition to rain. /CAB/&&.AVIATION...(12Z TAFS)Issued at 539 AM CST Sun Jan 5 2025MVFR to IFR cigs and even some vsbys continue to develop across the area and should remain this way through the morning. By midday we should see enough mixing to at least see improvement to MVFR if not VFR. Scattered showers are expected by midday out ahead of the cold front. A strengthening low-level jet over the northern half of the area will cause some LLWS impacts for those terminals (MCB, ASD, and GPT) during the late evening timeframe. The cold front is expected to make its way through the area during the late evening and overnight. Although the storms along the front should be weakening, still expecting showers and thunderstorms along it as it moves through the area late tomorrow evening and night. Any PoP or LLWS concerns diminish shortly after the front passes through the area, and a return to VFR conditions is expected thereafter. /CAB/&&.MARINE...Issued at 539 AM CST Sun Jan 5 2025SFC low continue to develop and has moved into central OK. Thishas already tightened the pressure gradient with strong southerly and southeasterly winds already in place across most of the coastal waters. These strong onshore winds will continue all day until the cold front passes through early tomorrow. Once that happens strong onrthwesterly to northerly winds will develop with high end small craft adv conditions in place. The cold front will also bring strong to possibly severe storms as it moves across thecoastal waters. High pressure will move in behind the cold front but headlines will likely be needed well into the work week. At this time it still looks like we may remain just below Gale however it will not be a surprise if the outer waters needed a Gale Warning behind the cold front for winds gusts near 40 kt. /CAB/&&.PRELIMINARY POINT TEMPS/POPS...MCB 73 28 40 24 / 80 100 0 0 BTR 79 32 44 28 / 60 100 0 0 ASD 75 33 45 27 / 60 100 0 0 MSY 78 36 46 32 / 50 100 0 0 GPT 70 34 48 28 / 50 100 0 0 PQL 74 36 51 26 / 50 100 0 0 &&.LIX WATCHES/WARNINGS/ADVISORIES...LA...Wind Advisory from noon today to midnight CST tonight for LAZ034>037-039-046>048-056>060-064>071-076>090. Cold Weather Advisory from midnight tonight to 9 AM CST Monday for LAZ034>037-039-046>048-056>060-065>067-071-076>087.GM...Small Craft Advisory until 6 AM CST Tuesday for GMZ530-532-534- 536-538-550-552-555-557-570-572-575-577.MS...Wind Advisory from noon today to midnight CST tonight for MSZ068>071-077-083>088. Cold Weather Advisory from midnight tonight to 9 AM CST Monday for MSZ068>071-077-083>088.GM...Small Craft Advisory until 6 AM CST Tuesday for GMZ532-534-536- 538-550-552-555-557-570-572-575-577.&&$$SHORT TERM...CABLONG TERM....CABAVIATION...CABMARINE...CAB
