Area Forecast Discussion
Issued by NWS Birmingham, AL
Issued by NWS Birmingham, AL
658 FXUS64 KBMX 021651 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 1151 AM CDT Tue Sep 2 2025 ...New SHORT TERM, LONG TERM, AVIATION... .SHORT TERM... (This afternoon through Wednesday) Issued at 1148 AM CDT TUE SEP 2 2025 This afternoon, scattered activity will be possible across mainly the northwestern half of the area, weakening in coverage and intensity after sunset. Instabilities will be fairly weak, with PW values in the 1.3 to 1.5 range, with higher values in the northwest, weakening towards the southeast. There appears to be a wedge of higher pressure to the east of the Appalachians, extending down into the state, allowing for an axis of lower PW values in the southeastern part of the state. The main activity will be showers, though with the higher PW and meager instabilities, a few thunderstorms could be possible in the northwest, with little to no impacts expected. Activity should weaken after sunset, with only a stray light shower possible overnight, mainly in the west. By Wednesday, a low pressure develops over the Great Lakes area, strengthening by the afternoon. The trough will deepen, causing the flow to impact areas across Alabama, with low and mid level flow becoming more consistent out of the west and southwest and increasing slightly. Steeper lapse rates and higher instabilities will be present across the entire area. However, moisture will struggle to return, with values remaining meager. Scattered activity could form, though thunder should be more isolated. Chances will be greater towards the north, closer to that low. With cloud cover expected to continue both days, temperatures will top out in the upper 80s, with limited moisture keeping heat indices at or a degree above the expected temps. 24 && .LONG TERM... (Wednesday night through next Monday) Issued at 1148 AM CDT TUE SEP 2 2025 The low over the Great Lakes will continue to strengthen through the end of the work week, with an associated front swinging through the Ohio and Tennessee Valleys. Forcing should be too far north of the area to create more than scattered showers and isolated thunderstorms in areas north of I20 Thursday. Friday, another disturbance moves around the low, reinforcing the boundary left by the front. This boundary will move south into northern Alabama sometime around Friday night and Saturday, where convection will become more widespread. Confidence is low on how far south that boundary will move, with a low chance for PW values will rebound through the day Friday ahead of this boundary as low and mid level flow strengthens out of the southwest, so there should be plenty of moisture to work with. By Sunday, models diverge on the next system. There is general agreement of a weak through and low pressure system developing somewhere over the MS River Valley and moving northeast. This feature would pick up the boundary over the state and transition it to the north as a warm front. There are large differences in timing of when this would happen. With either solution, would expect showers and thunderstorms each day through the next work week. 24 && .AVIATION... (18Z TAFS) Issued at 1148 AM CDT TUE SEP 2 2025 VFR conditions should prevail through the TAF period, with scattered showers and a low chance for isolated thunderstorms this afternoon in the northwestern half of the state. Overnight, winds should become calm, with a transition to the southwest by the end of the TAF period Wednesday as a trough influences the area. There is a low chance for isolated to scattered convection late Wednesday morning through the early afternoon, though confidence on timing was too low to include in any TAF for now. 24 && .FIRE WEATHER... Min RH values will range from 35-50% this afternoon across central and southern counties, with chances for isolated to scattered showers across northern portions of the area through Wednesday associated with shortwave activity. Moisture values will remain relatively steady for the next few days, and will be above critical thresholds. 20ft winds will continue to be light and variable, increasing to 5-7 mph from the southwest by Thursday. There are no fire weather concerns at this time. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 84 62 85 64 / 30 30 30 20 Anniston 84 63 84 65 / 20 20 20 10 Birmingham 86 66 86 67 / 30 20 30 10 Tuscaloosa 88 66 88 68 / 50 20 20 10 Calera 86 65 87 67 / 30 20 20 10 Auburn 85 64 87 66 / 10 10 10 10 Montgomery 88 64 89 68 / 10 10 10 0 Troy 87 63 87 66 / 10 10 10 0 && .BMX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...24 LONG TERM....24 AVIATION...24