489 FXUS64 KBMX 191147 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 647 AM CDT Tue Oct 19 2021 .UPDATE... For 12Z Aviation. && .SHORT TERM... /Updated at 0332 AM CDT Tue Oct 19 2021/ Today through Wednesday. This AM we have a mostly clear satellite picture, except for some thin high clouds noted across Central Alabama. Also, with the generally clear skies, cool conditions and near calm winds some patchy fog is noted along rivers and valleys. Some patchy fog may be noted through around 8-9am. Surface ridging is noted across the E 1/3 of Conus this AM and is expected to continue through the short term for the most part. Now through Wednesday, we will see some slow weakening of the ridge with temperatures and dew points moderating through the short term. With moisture starting to return around the E Conus ridge slowly, an isolated shower will be possible in the far southwest during Wednesday afternoon. However, most of the activity should hold off until later on Thursday as the next system approaches. 08 .LONG TERM... /Updated at 0332 AM CDT Tue Oct 19 2021/ Thursday through Monday. Rain and thunderstorm chances increase across Central AL late Wednesday night through late Thursday. A cold front associated with a low pressure system moving through the Great Lakes region will push southeastward towards Central AL under quasi-zonal flow aloft. Instability ahead of the front could increase to over 1000 J/kg with decent mid level lapse rates, which would support thunderstorm development. The weak flow aloft and lack of significant forcing should limit any severe potential with thunderstorms that do develop in our area. There's still some uncertainty on what happens to the frontal boundary Thursday night through Friday. Some guidance suggests the front stalls across Central AL and lifts back northward, while other guidance has the front pushing south and east of our area before stalling across the Northern Gulf Coast. For now, I've kept 15-20% chance for showers through much of the day on Friday to account for the slower solutions, but any moisture and forcing should decrease by Friday evening, leading to little to no rain chances for the weekend. An area of high pressures over the Coastal Carolinas strengthens on Monday as slight ridging build in across the Gulf States aloft. This should keep our area rain-free as we head into next week, though temperatures and moisture should begins to trend upward with the increased southerly flow. 25/Owen && .AVIATION... 12Z TAF Discussion. Surface ridging is in place across E 1/3 of Conus and will remain generally so through the TAF period. Satellite is currently indicating some SCT cirrus about. With cool temperatures and near calm winds, some patchy valley and river fog may occur at times through ~14Z. The best chances continue to be at MGM. I have MVFR tempo IFR VIS there. Elsewhere, I have MVFR tempos at ASN/TCL. Light E-SE winds are expected during the late morning into the afternoon with mixing ~5-7kts. Note: AMD NOT SKED is appended at KBHM due to ASOS power loss until further notice. 08 && .FIRE WEATHER... A dry airmass will persist today with afternoon minimum RH values in the 35-45% range. Increasing moisture ahead of a cold front will increase afternoon RH values above 50% Wednesday afternoon. Rain chances return late Wednesday night through Friday afternoon as a cold front moves through the region. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 74 47 77 59 76 / 0 0 0 30 60 Anniston 77 51 79 62 76 / 0 0 0 30 60 Birmingham 75 55 78 63 76 / 0 0 0 40 60 Tuscaloosa 75 56 79 64 78 / 0 0 10 40 50 Calera 75 54 78 64 76 / 0 0 0 40 60 Auburn 74 52 78 61 76 / 0 0 0 30 50 Montgomery 79 54 82 65 80 / 0 0 0 40 60 Troy 78 54 80 63 80 / 0 0 0 30 60 && .BMX WATCHES/WARNINGS/ADVISORIES/... None. && $$