946 FXUS64 KBMX 291215 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 615 AM CST Sun Nov 29 2020 .UPDATE... For 12Z Aviation. && .SHORT TERM... /Updated at 406 AM CST Sun Nov 29 2020/ Today through Monday. The satellite is currently indicating considerable high cloudiness across Central Alabama this AM. Our next weather maker, a surface low pressure system, is still out over the TX coast. It is expected to move to the ENE along the NW Gulf Coast and into S AL now into this evening. It is then expected to race NE up the Atlantic States as another front catches up with it. In the upper levels, a closed upper low over the TX/OK Panhandle will open up and swing eastward across TX/OK/AR/LA today. Ahead of it, extensive high moisture will continue to be ejected out across the Deep South. This evening, this upper low is expected to be absorbed into the main upper trough digging ESE across C Conus tonight and then across E Conus on Monday. Showers and a few thunderstorms are expected to spread across C AL today as the system gets closer and moisture increases . Currently, the atmosphere has a bit of work to do to recover with dew points anywhere from 39 at Haleyville to 54 at Troy as of 10z. While some gusty winds are possible, instability is meager. However, all should get some beneficial rain through tonight. The system will quickly pull to the NE on Monday. However, with the upper system still going across E Conus, a few very light showers are possible across the NE counties. As the upper low is moving across Monday, colder air will be invading as well. During the late afternoon hours, some flurries may be mixed in with the rain sprinkles before all of the moisture is tapped out. No accumulations or impacts are expected as moisture will be very shallow. 08 .LONG TERM... /Updated at 406 AM CST Sun Nov 29 2020/ Monday night through Saturday. A strong vorticity maximum will be located over the forecast area Monday evening as deep trough becomes an closed low over the eastern United States. There may be enough lingering moisture and steep lapse rates for flurries across our northeastern counties during the evening. Strong cold advection will continue overnight with lows on Tuesday morning ranging from the lower 20s northwest to the upper 20s southeast. Temperatures will only rise into the 40s during the afternoon for most of our forecast area as cold northwest flow continues. Temperatures will moderate for Wednesday and Thursday as heights rise in advance of a developing trough over the Southern Plains. deep-layer westerly flow develops. The upper-level trough is expected to be rather slow-moving, with sufficient time for southerly flow to transport moisture northward. Rain may begin affecting our western areas Thursday afternoon into Thursday night and slowly move eastward on Friday. Exact timing is unclear which is currently a limiting factor for POPs for any given 12 hour period. The upper-level trough is expected to move east of the area on Saturday with cooler and dry conditions to follow. 87/Grantham && .AVIATION... 12Z TAF Discussion. Conditions will deteriorate as we progress during the day as a low pressure system over the NW Gulf moves toward AL today. Ahead of the system, some IFR/MVFR cigs will make some meager progress from GA into TOI/ANB respectively. At the same time, MVFR conditions will move in from SW with the SHRA activity (& some TS) later this morning. Conditions should go to IFR for many during the late afternoon and all by evening. Winds will be gusty as the front moves through tonight. 08 && .FIRE WEATHER... Rain will become widespread by this afternoon and evening as a strong storm system moves through. Much colder and drier conditions will arrive for Monday and Tuesday with northwesterly flow. RH values will remain quite high through Monday. Much lower RH values are expected for Tuesday. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 61 37 45 25 45 / 100 100 10 10 0 Anniston 63 42 46 26 46 / 100 100 10 10 0 Birmingham 61 40 45 27 47 / 100 100 10 10 0 Tuscaloosa 60 40 46 26 50 / 100 90 0 0 0 Calera 61 41 46 28 47 / 100 100 10 10 0 Auburn 61 45 48 28 46 / 100 100 10 10 0 Montgomery 64 45 51 28 50 / 100 100 0 0 0 Troy 66 45 51 28 50 / 100 100 0 0 0 && .BMX WATCHES/WARNINGS/ADVISORIES/... None. && $$ 08/87