733 FXUS64 KBMX 091140 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 540 AM CST Sun Dec 9 2018 .UPDATE... For 12Z Aviation. && .SHORT TERM... Today and Tonight. The main bulk of the rain and possible gravity wave have pushed out of the area this morning. Meanwhile another spoke energy providing lift is moving through eastern counties and will exit the area by 5 am. The main upper low is sliding east across western Tennessee into middle Tennessee and will lift east northeast during the day. The main surface low is now northeast of Apalachicola and will continue to slide east through the morning. In between we will see scattered showers throughout the day as spokes of energy slide between the two systems. It will be another cold day, with the best rain chances in the northwest this morning, then the northeast this afternoon. The upper low will be slow to move away from the area and could result in precipitation continuing through the night and into Monday, but more on Monday in the long term. For tonight, temperatures will begin to fall in the west, but the precipitation there should be done. The northeast, the precipitation will still be around but the temperatures will not be as cold since the cloud cover will help keep the area a touch warmer. However, looking at the atmospheric column there is a chance that some flurries will mix in across the northeast late this evening. With temperatures expected to remain above freezing at the surface and overall fairly light precipitation, accumulations are not expected on the surface. Highs today will be in the 40s, with lows dropping into the 30s and low 40s. 16 .LONG TERM... Monday through Sunday. The surface low is well into the Atlantic by Monday morning, but the larger scale upper level trough is still hanging back over much of the eastern half of the CONUS. Another upper level low swings through the trough during the day Monday, leading to at least some chance for scattered showers, mainly across Eastern and Northeastern portions of Central AL. I can't rule out a few flurries in Cherokee County early Monday morning, but this should be short-lived and no accumulation is expected. Otherwise, Monday will be another cold day across Central AL with highs not making it out of the 40s. By midnight Monday evening, the main trough axis has pushed east of our area, allowing ridging to build in from the west. This will clear out any remaining rain chances overnight into Tuesday morning. High pressures remains in place across the Southeastern CONUS through at least Wednesday evening, so expect Tuesday and Wednesday to be drier and colder with the cold air mass in place. Meanwhile, on Wednesday, a shortwave trough is swinging through the Southern Plains and steadily weakens as a stronger trough digs into the Rockies. The shortwave energy gets ejected eastward into the MS River Valley early Thursday morning. This will increase our rain chances from west to east during the day Thursday. The stronger trough deepens and forms a closed upper level low over the Southern Plains by Thursday afternoon, leading to the development of a surface low that will push eastward into the ArkLaTex in the afternoon. Rain becomes widespread Thursday evening through Friday as the surface low slides eastward through the Gulf States. Winds will also increase as the surface pressure gradient tightens with the approaching low. At this time, instability looks limited with this system, as was with this previous system, so I have not mentioned any thunder in the forecast, but this will need to be monitored in coming days. Also, guidance has temperatures running roughly 5-10 degrees warmer with this system compared to the one from yesterday, so this should prevent any winter precip talk in the extended forecast for now. The trough pushes east of our area through the overnight hours into Saturday morning, so we'll see a gradual decrease in rain chances into the weekend as ridging builds back into the region. 25/Owen && .AVIATION... 12Z TAF Discussion. Ceilings are dropping and will remain low through the day. Look for IFR cigs through the period with winds of 7 to 10 kts. May even see some LIFR cigs by 6z at all sites. Periods if light rain will be possible across the north with a few areas of drizzle today in the south. 16 && .FIRE WEATHER... Scattered rain possible today and Monday. Drier conditions expected Tuesday and Wednesday next week, ahead of the next rain system. There are no fire weather concerns at this time. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 42 35 43 28 50 / 90 30 40 20 0 Anniston 42 36 44 29 52 / 70 40 30 20 0 Birmingham 44 35 43 28 51 / 70 20 20 20 0 Tuscaloosa 45 36 45 30 53 / 40 20 10 10 0 Calera 44 35 44 31 52 / 50 20 20 20 0 Auburn 42 36 45 34 53 / 50 20 20 20 0 Montgomery 47 38 47 33 54 / 50 20 10 10 0 Troy 48 37 46 34 54 / 40 20 10 10 0 && .BMX WATCHES/WARNINGS/ADVISORIES/... None. && $$