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777 FXUS64 KLIX 091043AFDLIXArea Forecast DiscussionNational Weather Service New Orleans LA443 AM CST Thu Jan 9 2025...New SHORT TERM, LONG TERM, MARINE....SHORT TERM...(Today through Friday)Issued at 340 AM CST Thu Jan 9 2025It has been a strange night. Everything began as expected, windsslacked off and temps quickly dropped then just before midnighteverything changed. No clouds moved in but many locations thetemps paused and a few even rose a degree or two. However thestranger issue was the winds picking back up. Winds were still outof the north and northeast and any location that had a body ofwater to the north saw wind gusts over 20 mph frequently. NEW evensaw wind gusts approach 30 mph. Temps finally began to fall againon the northern half of the CWA but very slowly while mostlocations on the southern half of the area practically stalledout. It is still possible for most of the area to see temps crashjust before sunrise is the winds completely shut down. Once thesun comes up we will begin to slowly warm up and just abouteveryone should be above freezing by 9. Today will generally be quiet as the bulk of our weather will holdoff till tonight, likely after midnight and well into tomorrow.The system that will bring us a lot of cold rain and winterweather across a good chunk of the deep south (just not us alongthe coast) is already starting to slowly get going. The closed lowover the Baja is start to open up but you can easily see the nextstrong disturbance dropping down the backside of the amplifyingL/W trough. At 8z that disturbance was digging through the the4 corners and as it continues to push S to SSW it will anchor thebase of our L/W trough. Southwest is already increasing out westand you can see on GOES16 the increase in large scale lift acrossthe entire state of TX and into the southern Plains and justentering the western Gulf. The sfc low is only just starting todevelop in the western Gulf near and just SSE of the TX/Mexicoborder. As this occurs an inverted trough will slowly develop north along the TX coast where strong boundary layer WAA will occur and the sfc low will take that route north before finally beginning to turn more NE and then ENE following the strongest WAAwhich will be along and south of the I-12 corridor. With that thesfc low looks a little more likely to track inland and that wouldlead to the heavier precipitation being slightly farther. Multiple models have shifted the track and basically bisects the CWA SW to NE as it crosses the area. A little hesitant completely buying the low getting that far north but coming onshore and crossing coastal SELA and possibly just offshore over coastal MS now looks likely. Unless things slow down even more or convection develops well ahead helping to anchor the BL WAA a little farther south I don't believe the sfc low will hang out over the water now. Everything else that has been advertised the last few days isstill in place. Increasing mid lvl support all night and all dayFriday across the Lower MS Valley with h5 winds approaching 110kts really emphasizes how dynamic this system will be. Again thatwill cause the LL to respond and the LL jet we have beenmentioning is still expected with h85 winds of 40-55 kt (possiblyabv 60) working across the area overnight and early Friday. This pumps in the moisture and WAA but as mentioned earlier with the slight trend northward of the sfc low that is also evident in the LL and mid lvls. The LL WAA is still very impressive over the areabut it also goes well to our northwest and north and not just contained over the area. That should lead to widespread moderateand isolated area of heavy precip. This does indicate the some of the heaviest precipitation would be just outside of the area now but some of the more intense rain should be associated just to thenorth and northeast of the sfc low and that will slide across ourarea. PWs are still expected to be in the 1.4 to 1.8" range whichis at and above the 90th percentile. This would still suggest that locally heavy rain is likely but the flash flood risk may notbe as high as previously thought with the slight northward shift.Again we will need to watch this close, if the system doesn't getas far north the potential for localized flooding across northernand northwestern areas of the CWA will increase. Still anticipating a broad area of 1 to 3 inches of rain with isolated higher amounts but that will likely be a sharp cutoff to the southand southeast of the sfc low track so some coastal areas of SELA may only see a0.25 to 0.5 an inch. The bulk of the rain will likely be between 6z and 18z Friday soafter midnight and through midday. After that the sfc low quicklyslides east and the rain will taper off from west to east. The other issue with this system is the winds. Again we alreadymentioned how dynamic this system is and winds don't just respondin the mid and Low lvls but the boundary layer winds will as well.Winds will begin to increase after midnight but typically unlessyou are right on the water and the wind is coming off of itconditions aren't optimal to see the wind greatly increase overnight. as we get closer to sunrise the winds will finally begin to respond and after sunrise winds could ramp up out of the south very quickly. The sfc low will continue to deepen as it moves into the area the pressure gradient will tighten and models are indicating a 6-7 mb change across the CWA. Without the cold air advection like we see behind a front this is typically at the point where we can get strong winds. As the sun comes up even with the rain and clouds mixing will be a little easier and with h85 winds as high as we are anticipating we will be able to mix down much stronger wind gusts and it would not be a surprise to see the southeastern half-2/3rds have a few wind gusts above 40 mph at times, especially to the east of the sfc low and coming offthe water. A wind advisory will likely be needed for Friday. /CAB/&&.LONG TERM...(Friday night through Wednesday)Issued at 340 AM CST Thu Jan 9 2025The bulk of the focus is in the short term and mainly the next36to 48 hours. The extended portion of the forecast is muchquieter with drier and still cool to cold conditions. We actuallymay never get a trough axis to pass through the area withWSW flow still in place through the weekend. This along with the subtropical jet still racing across the Lower MS Valley and southeastern CONUS likely helps to keep cirrus streaming across the region. This will also likely develop another Gulf low butwell south into southwest and into the central Gulf. We may seesome overrunning type shower activity Sunday with this feature but it should push east of the area with a reinforcing shot of cool and dry air Sunday night and Monday. Heading into the work week it looks quiet but the models againstruggle as multiple system work through the flow. That said welook to remain dry and cool. /CAB/ &&.AVIATION...(06Z TAFS)Issued at 1137 PM CST Wed Jan 8 2025Currently VFR conditions across all terminals, and that is likelyto continue overnight. There's considerably less cirrus aroundthan last night, or even this afternoon...for now. There are somemid level clouds around FL080 over southwest Louisiana, andforecast soundings indicate those should make it into at least thewestern terminals by about mid-morning Thursday. Don't reallyanticipate ceilings falling into the MVFR range until after sunsetThursday. Any surface visibility restrictions are unlikely untilabout 24 hours from now, although there may be some light rain, atleast aloft, during the 00z-06z time frame. Conditions willdeteriorate toward sunrise Friday with IFR ceilings arriving fromwest to east as rainfall rates increase and lower layers continueto saturate. Will carry mention of LLWS after 06z Friday at KMSYas low pressure strengthens. This is beyond the range of theforecast at remaining terminals, but expect that the 12z packagemay need to mention it at other terminals. Threat of TSRA appearsto be too low to mention at this time. &&.MARINE...Issued at 340 AM CST Thu Jan 9 2025Things have not been cooperating over the coastal waters overnight and this morning. Winds picked back up late this eveningand continue to increase after midnight. After multiple obs had wind gusts over 20 kts we issued a SCY through 15z for all of the coastal waters and then the water west of the mouth of the river will remain in the SCY through 18z. The main impact will be tonight and through tomorrow night associated with the sfc low moving through over that time. Conditions rapidly deteriorate thisevening as the sfc low continues to deepen and finally begins to push towards coastal LA. Just like was mentioned in the short termportion of the discussion a key feature to indicate the possibility of Small Craft adv or even Gale conditions is the pressure gradient and how much it changes across the area. typically 4-5 mb can get us low end SCY but as we approach 6-7 mblike we are expected tonight and early tomorrow winds will be well into SCY criteria and likely near Gale. That said the winds just off the water will ramp up even more and could provide numerous wind gusts of 35 to 40 kts. This appears to now be possible over all of the waters and because of that we have addedthe rest of the coastal waters to the GLA. We did not upgrade to a warning yet however it seems almost certain that at the least the open waters will get Gale Force winds. However the sounds and tidal lakes not quite as confident yet but the tidal lakes look tohave a rather good chance as this will be much closer to the sfc low. After the sfc low pushes east winds will veer around to westerly and then northwesterly. Also winds will weaken some but they likely won't drop significantly before picking back up like typical with cold front and SCY conditions will continue with strong SCY conditions Friday afternoon and night expected. Winds finally back down early Saturday as high pressure builds in acrossthe deep south. /CAB/&&.PRELIMINARY POINT TEMPS/POPS...MCB 47 36 44 30 / 20 100 100 0 BTR 49 41 51 35 / 30 100 90 0 ASD 52 41 58 34 / 20 60 100 0 MSY 52 47 62 37 / 20 70 100 0 GPT 51 41 62 34 / 10 50 100 10 PQL 54 41 64 35 / 10 40 100 10 &&.LIX WATCHES/WARNINGS/ADVISORIES...LA...Freeze Warning until 9 AM CST this morning for LAZ046>048- 056>059-065-076-079>086.GM...Small Craft Advisory until 9 AM CST this morning for GMZ530-532- 534-536-538-555-557-575-577. Gale Watch from late tonight through Friday afternoon for GMZ530- 532-534-536-538-550-552-555-557-570-572-575-577. Small Craft Advisory until noon CST today for GMZ550-552-570-572.MS...Freeze Warning until 9 AM CST this morning for MSZ083>088.GM...Small Craft Advisory until 9 AM CST this morning for GMZ532-534- 536-538-555-557-575-577. Gale Watch from late tonight through Friday afternoon for GMZ532- 534-536-538-550-552-555-557-570-572-575-577. Small Craft Advisory until noon CST today for GMZ552-570-572.&&$$SHORT TERM...CABLONG TERM....CABAVIATION...RWMARINE...CAB
