738 FXUS64 KLIX 062351 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 651 PM CDT Wed Oct 6 2021 .AVIATION (00Z TAF DISCUSSION)...Widely scattered showers have formed along weak seabreeze boundaries near KHUM, KASD, and KHDC in the past couple of hours. These showers will quickly dissipate within the hour, and are not mentioned in the TAF package. The bigger concern will be another favorable night for some low stratus and fog development. Have included IFR and LIFR conditions in the forecast for KGPT and KHUM as conditions look most favorable for fog development in these locations. The remaining terminals should see a mix of MVFR and VFR conditions as a scattered to broken stratus layer ranging between 1000 and 2000 feet forms around daybreak. Any fog and low stratus will quickly mix out by 15z, and prevailing VFR conditions are expected through tomorrow evening. PG && .PREV DISCUSSION... /issued 527 PM CDT Wed Oct 6 2021/ AFTERNOON UPDATE...Quick update to increase POP values into the low end chance range of 20 to 30 percent over Lower Jefferson, Lower Lafourche, and Terrebonne Parishes to reflect an area of widely scattered shower activity that has formed along a weak seabreeze boundary. These showers will be short-lived and will dissipate very quickly as sunset approaches and instability wanes. PG PREV DISCUSSION... /issued 318 PM CDT Wed Oct 6 2021/ SYNOPSIS...Extremely large cut-off low continues to spin over the upper portions of the Lower MS Valley. It remains tapped into a deep plume of moisture draped south from central TN into GA and then the eastern Gulf. Very dry air is quite evident on WV to the south, especially across the northwestern and western Gulf. WV also clearly shows that this low is cutoff with the ridge squeezed to it west and then substantial ridging to the north and northeast. Next L/W trough is already moving on shore over the Pac coast. At the sfc the cold front associated with the cut-off low has basically stalled from near MEM to just east of MOB and then south-southwest into the Bay of Campeche. A warm from extends east from the MO/AR border and through the Ohio Valley. Outside of those 2 fronts high pressure is dominating much of the eastern half of the CONUS. /CAB/ SHORT TERM...Quite the pleasant October day today. Temps did warm up into the mid 80s. Scattered to broken cold cu(well I guess we could call it cold weather cu) developed rather quickly as we heated up but considering RH values dropped off below 75% above 4k ft these were quite shallow cu. However, at 19z we did finally get a shower to develop near Lafitte as the weak seabreeze came from the the east and collided with the lake breeze from the north. The main forecast driver is the cut-off low located just off to our north. This feature will be very slowly to leave but finally by Friday it should should be approach the southern edge of the Great Lakes. It will remain blocked from getting out of here as the ridge to its north will only slide to the northeast and still be firmly entrenched over the northeast CONUS. As our low slides north we will see mid level hghts rise over the region with moisture continuing to be suppressed to our east and south. The edge of that moisture tongue will remain close to coastal MS and the outer waters which could see top a few showers after we warm up some but overall look for tomorrow and Friday to be rain free for just about everyone. As for temps...we did warm up into the mid 80s today with many locations hitting at least 86 and it wouldn't be a surprise to see one or two 87s out there. Highs will likely be at the least similar to today over the next few days if not a touch warmer for most places. h925 temps should remain around 21C over the next 2 days and that translated to the sfc would be around 86 but add another degree or two and 87 to 88 is not out of the question but that may be easier to achieve on Saturday. As for lows, this is a little more tricky. winds will be rather light if not calm overnight and with no real clouds impacting the area overnight radiational cooling conditions will be good. the ground is drying out after no rain the last few days and that could also help with the cooling overnight. One last thing, we actually could advect slightly drier BL air into the area with dewpoints into the mid to upper 50s over the next 48- 60 hrs and this may be good enough to get some locations to fall into the upper 50s. Especially friday morning and perhaps Saturday morning. By Saturday the low should finally open up leading to a L/W trough now stretching from the Great Lakes to just east of FL. This will keep the region dry through Saturday as northwest flow will remain over head. PWs will still be around or just over 1" and with a ridge building over TX rain will have a very difficult time developing. H925 temps continue to warm about another degree and with that we can not rule out a few locations seeing highs in the upper 80s. /CAB/ LONG TERM (Saturday through Wednesday)... As the high pressure builds in over the weekend, that along with dry air will help keep the PoPs non existent, with max temps climbing into the mid 80s. Upstream of SE LA and Coastal MS, a low pressure forms over the Rockies and Panhandles of TX/OK. While it is still a bit early for a Texas Low to form, the guidance is showing that the track is similar to the Climo pattern this system normally follows. With the Texas Low, heading for the Great Lakes region, a boundary does seem to be tracking toward AR/LA. However the guidance does have a slight disagreement on the exact location of where this boundary stops. Current guidance is showing this boundary stopping close to the AR/LA boarder, about Tuesday. This helps bring PoPs in the area closer to 20%. However PWATs are below the Climo average, but not quite at the 20th percentile. /KO/ AVIATION...18Z TAF Package...No concerns for flights today or tonight. VFR conditions will persist. Not completely out of the question but ASD and GPT could see MVFR vsbys for about an hour or two between 11-14z but not confident enough to add that to the TAFs yet. /CAB/ MARINE...Marine conditions should be fairly quiet with no major impacts expected. Winds will likely remain light and variable the next few days with winds near the coast determined by diurnal fluctuations. Winds may finally become more steady out of the south late this weekend as high pressure finally pushes far enough to the northeast and low pressure deepens over the Central Great Plains and tracks towards the Upper MS Valley. /CAB/ && .PRELIMINARY POINT TEMPS/POPS... MCB 61 85 61 86 / 0 0 0 0 BTR 62 85 61 87 / 0 0 0 0 ASD 63 88 62 89 / 0 10 0 10 MSY 69 86 68 87 / 0 10 0 10 GPT 67 86 65 87 / 10 10 10 10 PQL 66 86 64 87 / 10 10 10 10 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$