Area Forecast Discussion
Issued by NWS Birmingham, AL
Issued by NWS Birmingham, AL
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
579 FXUS64 KBMX 250809 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 309 AM CDT Tue Jun 25 2024 ...New LONG TERM... .SHORT TERM... (Today through Wednesday) Issued at 201 AM CDT TUE JUN 25 2024 A quiet but warm overnight period is ongoing across the Deep South with the remnant surface boundary currently across southern portions of our county warning area. Slightly drier air at the surface currently exists north of the boundary, with lower 60s dewpoints across far northeast counties. Meanwhile, very muggy surface conditions exist farther to the south, with mid 70s dewpoints observed at Demopolis and Troy. With the slightly drier air in place across the north, we`ll see temperatures drop down into the mid and upper 60s, while low to mid 70s are likely at sunrise across the U.S. 80 and I-85 corridors. Dry northerly flow will exist across much of the atmospheric profile during the day today, which will also cause our daytime temperatures to easily rise into the upper 90s to near 100 degrees. The only thing saving us from having to issue heat advisories is the drier northeasterly flow, which will mix dewpoints down into the upper 50s to lower 60s during the peak heating of the afternoon. However, heat indices are still expected to rise into the 100 to 103 degree range across far western counties where low level moisture is a tad higher. Following another warm and mostly clear night tonight, 500mb flow will become northwesterly during the day on Wednesday as the upper ridge centers over the desert southwest. An upper level shortwave trough is expected to move southeast through the Great Lakes states with the trough axis stretching southward into Kentucky and western Tennessee. Another 500mb vort max is expected to move towards our area by Wednesday afternoon, which will help to develop showers and storms to our west and northwest perhaps in the form of an MCS. Areas west of I-65 currently have the best chance of seeing thunderstorm activity during the late afternoon and into the evening hours. Dry air across eastern Alabama should limit development in those areas, but guidance is indicating a fairly good chance of low level moisture persisting across the west. CAMs this morning are indicating a good chance of scattered to perhaps numerous storms in the west and northwest, some of which could be strong to severe at times. We`ll have plenty of dry air aloft to work with, so if we can get enough lift from mesoscale boundaries or an MCS we may need to keep an eye on severe development as temperatures rise into the mid to upper 90s. Gusty microburst-type winds will likely be the main hazard. Effective northwesterly shear could also keep some updrafts going a bit longer as well. We`ll continue to keep an eye on mesoscale trends to better determine potential hazards. 56/GDG && .LONG TERM... (Wednesday night through next Monday) Issued at 310 AM CDT TUE JUN 25 2024 Key message: - Hot conditions return Friday through the rest of the period, with increasing humidity levels. Forecast heat indices are near 105 degrees Friday and Saturday, increasing to 105 to 110 degrees Sunday and Monday. At least scattered showers and storms will continue Wednesday night along convective outflows as a shortwave trough moves into the area. This shortwave will become more positively tilted on Thursday as ridging begins to build back eastward towards the Lower Mississippi Valley. The progression of the trough and the drier air aloft moving in aloft behind it seem to have slowed slightly. The shortwave aloft and a trough at the surface should trigger scattered showers and storms across at least the southeast half of the area. The convection and associated cloudcover should keep highs generally in the lower 90s, but it will be more humid than recent days. Strong subtropical ridging builds back over the area Friday and Saturday. This time higher PWATs will remain over the area meaning there will still be chances for scattered diurnal convection, though probably not enough coverage to have any widespread impacts on temperatures. Highs will be climbing back into the mid 90s and dew points will be higher than they have been recently, meaning heat indices will be around 105. The ridge retrogrades slightly Sunday and Monday, putting Central Alabama under northwest flow aloft. A front will attempt to approach the area, but the only effect will actually be to increase dew points as moisture pools south of the front. This will cause heat indices to increase to the 105-110 range. Scattered showers and storms will remain possible, potentially aided by the boundary to our north and weak impulses rotating around the ridge. 32/Davis && .AVIATION... (06Z TAFS) Issued at 201 AM CDT TUE JUN 25 2024 VFR conditions will continue through the forecast period with mostly clear skies and light northerly surface winds. 56/GDG && .FIRE WEATHER... Hot conditions continue today with RH values dropping into the 25 to 35 percent range. A couple spots in East Alabama may drop below 25 percent but winds will be light. Moisture begins to increase from the west on Wednesday, but RH values in East Alabama will still drop into the 28 to 35 percent range. Rain-free conditions are expected today, with chances for showers and storms returning from the west on Wednesday. Scattered, mainly afternoon and evening showers and storms are expected Thursday into the weekend, with the highest coverage in the southeast. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 97 68 99 70 / 0 0 20 40 Anniston 96 70 98 72 / 0 0 20 30 Birmingham 99 74 99 73 / 0 0 30 40 Tuscaloosa 99 73 96 72 / 0 0 40 50 Calera 100 72 99 73 / 0 0 30 40 Auburn 97 73 97 74 / 0 0 20 20 Montgomery 99 71 99 72 / 0 0 30 40 Troy 99 71 99 72 / 0 0 40 30 && .BMX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...56 LONG TERM....32/Davis AVIATION...56