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
44
45
46
47
48
49
768 FXUS64 KBMX 260056 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 756 PM CDT Wed Sep 25 2024 ...New SHORT TERM... .SHORT TERM... (Tonight through Friday) Issued at 756 PM CDT WED SEP 25 2024 Showers and storms associated with a pre-frontal trough have largely pushed eastward into Georgia. Meanwhile the cold front continues to move slowly southeastward through the area, with an isolated shower at times along it and other boundaries. An upper low remains centered near Paducah Kentucky, while Hurricane Helene is strengthening over the southern Gulf. Overall rainfall rates should be lower overnight, though even light to moderate rain could cause minor flooding issues over portions of our southeast counties where 2 to 5 inches of rain fell. Cooler air will also work down into some of our far northern counties. As another vort max rounds the base of the upper low, and convergence strengthens along a surface trough north of Helene and old frontal boundary, rain will increase again from east to west late tonight and tomorrow. Heavy rainfall rates returning tomorrow will result in an increasing flash flood threat. Temperatures will remain limited across the east by precipitation, but will warm up more across the west. 32/JDavis Previous short-term discussion: (This evening through Thursday) Issued at 1218 PM CDT WED SEP 25 2024 Tonight, there could be a break in rain as the boundary weakens and the outer bands of Helene move approach the coast. Scattered activity will be possible, mainly in the east through the early morning hours. The outermost bands of helene will begin to impact the area beginning early Thursday, with widespread rain moving south to north, with coverage increasing through the day as Helene moves north. PW values will be at absolute max for this time of year, with more consistent coverage, and higher accumulation values in the east, with amounts decreasing incrementally the farther west of I65 the bands reach. A Flood Watch will remain in effect through Friday morning to account for the rain accumulations from the scattered activity today, and the widespread heavy rain expected to increase from Helene. Winds will begin increasing in response to Helene by early Thursday afternoon. A Tropical Storm Warning will be in effect through Friday morning to account for increasing winds and high rainfall totals. 24 && .LONG TERM... (Friday through next Tuesday) Issued at 337 AM CDT WED SEP 25 2024 Helene is expected to weaken to a tropical depression by Friday morning and then quickly becomes absorbed into the larger-scale cut- off low by Friday evening. There will be some wrap-around rainfall across the northern half of Central AL during the day on Friday before dry air gets wrapped in, decreasing the footprint of rainfall around the cut-off low Saturday through Sunday. This cut-off low persists over the region through at least Monday before shifting to our east Monday night into Tuesday. I won`t completely rule out some lingering shower activity under the closed upper level low over the weekend, but most guidance keeps the area rain-free, so my confidence to mention any rain chances is too low right now, but it`s something we`ll need to watch for in the next few days. 25/Owen && .AVIATION... (00Z TAFS) Issued at 629 PM CDT WED SEP 25 2024 Showers and storms have moved east of the terminals and should remain there much of the night, though some isolated to scattered showers will remain possible (20-40% chances). MVFR cigs continue to linger near MGM, while the other terminals should remain VFR for much of the night. Deteriorating conditions are expected Thursday as Hurricane Helene approaches the Gulf Coast. Rain will move back westward, while thunder probabilities will be too low to mention at this time. MVFR to IFR cigs and visibilities will be expected except at TCL, while any gusts above 25 kts will hold off until after the current TAF cycle. 32/JDavis && .FIRE WEATHER... With tropical moisture increasing ahead of Hurricane Helene and a stalled frontal boundary, widespread rain is expected through Thursday, with rain chances diminishing through the day on Friday. Minimal RH values will be above 60% through the weekend. Winds increase substantially on Thursday as the tropical system approaches the northern Gulf coast. Wind gusts of 25-30 mph are possible for much of Central Alabama, with gusts exceeding 40mph in the eastern half of Central AL. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 63 75 62 74 / 40 90 90 70 Anniston 65 74 65 76 / 50 100 100 60 Birmingham 64 77 64 73 / 30 60 80 60 Tuscaloosa 65 81 63 75 / 20 30 60 50 Calera 66 77 65 75 / 30 60 80 50 Auburn 68 75 65 77 / 80 100 100 30 Montgomery 70 77 65 79 / 60 90 90 20 Troy 69 75 63 78 / 80 100 100 20 && .BMX WATCHES/WARNINGS/ADVISORIES... Flood Watch from Thursday afternoon through Friday morning for the following counties: Autauga-Blount-Chilton-Jefferson-Lowndes- Shelby. Wind Advisory from 7 PM Thursday to 1 PM CDT Friday for the following counties: Autauga-Blount-Calhoun-Chilton-Clay-Coosa- Elmore-Etowah-Jefferson-Lowndes-Montgomery-Shelby-St. Clair- Talladega-Tallapoosa. Flood Watch through Friday morning for the following counties: Barbour-Bullock-Calhoun-Chambers-Cherokee-Clay-Cleburne-Coosa- Elmore-Etowah-Lee-Macon-Montgomery-Pike-Randolph-Russell-St. Clair-Talladega-Tallapoosa. Tropical Storm Warning for the following counties: Barbour- Bullock-Chambers-Cherokee-Cleburne-Lee-Macon-Pike-Randolph- Russell. && $$ SHORT TERM...32/JDavis LONG TERM....25 AVIATION...32