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
50
059 FXUS64 KBMX 080618 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 118 AM CDT Wed May 8 2024 ...New AVIATION... .SHORT TERM... (Tonight through Thursday) Issued at 810 PM CDT TUE MAY 7 2024 Limited lapse rates and limited insolation helped limit the overall convection this afternoon and evening. One storm was able to maintain its updraft and became a right mover that was near far northern Cherokee County. But this has been the outlier so far and expect rain chances to gradually dwindle overnight. It should almost be a repeat performance by morning. Clouds will develop and hang around a few hours before lifting by afternoon. Isolated to scattered showers and thunderstorms are again possible on Wednesday. A few storms may be severe north in the afternoon and early evening, but should be limited in coverage. A better chance is anticipated Late Wednesday night into Thursday. 75 Previous short-term discussion: (This evening through Wednesday) Issued at 131 PM CDT TUE MAY 7 2024 This afternoon. The mid-level longwave ridge axis will move further to the east of the area this afternoon while a zonal flow aloft with some shortwave disturbances will move east over the area through the afternoon and evening hours. Surface high pressure is centered well offshore of the Southeast Atlantic Coast but is elongated and extends west across much of Florida. Expect shower activity to continue to develop across our western and central counties and expand east with time. Some of the showers may build into thunderstorms will be possible later this afternoon and into early evening if enough instability materializes. Winds will be from the southwest at 7-14 mph. High temperatures will range from the mid 80s far north and northeast to the low 90s far south. Tonight. A more southwest flow develops over the area tonight as longwave ridging moves further east over much of the Mid Atlantic and Southeast Coastal areas while a large upper low spins over the Western Dakotas. Surface high pressure will remain centered over the Southwest Atlantic Basin, but will continue to nose westward toward the Wiregrass Region. A few weak shortwaves in the mid levels will continue to move east over the area, providing enough uplift for a continuation in shower and storm chances, though this will largely be concentrated across the northwest half of the area. Showers will remain the predominant element, but a few thunderstorms will remain possible. Some patchy fog may develop across portions of the south and southwest before daybreak. Winds will be from the south to southwest at 4-8 mph. Low temperatures will range from the upper 60s far east to the low 70s far southwest. Wednesday. The sprawling upper low will become centered over the South Dakota and Nebraska border on Wednesday while little change occurs at the surface with the forecast area remaining between high pressure to our southeast and lower pressure across Texas, extending northeast into the Midwest. Chances for showers and some thunderstorms will be greatest generally along and north of the Interstate 20 corridor with a scattered coverage. Isolated coverage is expected elsewhere. Winds will be from the south to southwest at 7-14 mph. Highs will range from the mid 80s in the higher terrain east to the low 90s across the southwest and far south. 05 && .LONG TERM... (Wednesday night through next Monday) Issued at 159 PM CDT TUE MAY 7 2024 A rather active weather pattern is taking shape across the region for the remainder of the work week with several windows for strong/severe thunderstorm potential. A series of shortwave impulses associated with an elongated trough situated from the Northern Plains to the Intermountain Region will eject eastward over the next 48 hours. The first of these impulses will aid in pushing a weak surface to 850 mb boundary toward the region Wednesday night. It`s highly likely that scattered strong to severe convection will form into a MCS as it tracks east southeast toward Alabama tomorrow night. The timing of this has slowed somewhat so the boundary later thermodynamics would potentially be less favorable for severe weather. However, the kinematics and deep layer profiles still look sufficient for damaging wind potential. Thursday looks to be a bit of a question mark for a variety of reasons. At these time scales it`s hard to time/pinpoint any potential remnant convection or outflows from the overnight MCS/QLCS. Any remnant boundaries or differential heating lines could be a genesis for redevelopment. However, if some of the more recent CAMs are correct and the overnight convection is even slower then the afternoon might end up being mostly dry especially across the northern half where the atmosphere would be sufficiently overturned. Having said that, many of the point soundings show a fairly volatile airmass with CAPES 2.5-3 Kj/kg and 60 knots of bulk shear if the airmass is semi-pristine. Based on the uncertainty have kept the PoPs on the higher end of the guidance for Thursday and Thursday night. It should be noted that the latest medium range guidance is still fairly consistent with yet another convective complex impacting mainly southern portions of Alabama Thursday night/early Friday. Subtle differences in the track will determine whether the primary impacts stay south of our forecast area. The profiles ahead of this feature look to be fairly unstable with decent mid level flow (but fairly weak low level flow) so this is another period that will need to be monitored closely. At this time, the weekend looks generally dry with some drier air working in from the north. A shortwave and associated surface low across the northern Gulf will bring rain back into the forecast for Sunday and Monday along the coast. The medium range guidance is edging north with this system and PoPs may need to included for our southeast quadrant for Monday (and possibly Tuesday) if this trend continues. 15/CBD && .AVIATION... (06Z TAFS) Issued at 1251 AM CDT WED MAY 8 2024 VFR conditions will dominate most locations through 8z, then MVFR ceilings will develop and affect all terminals by 08-10z. There may be some IFR ceilings around and added a tempo for a few locations. Additionally, patchy fog may also be present but should not be overly widespread. The ceilings will slowly rise and become VFR by 16-18z. Showers and thunderstorms are possible again this afternoon and have the northern sites in a PROB30 during the afternoon hours. Winds will be light south southwest overnight and becoming 5-10 kts during the day. Winds will remain strong through the evening. 16 && .FIRE WEATHER... Isolated to scattered showers and storms are possible this afternoon with greater rain chances overnight and Thursday. Rainfall amounts will average 0.5-1.0 inch under heavier storms. Afternoon minimum RH values will be above 45-50 percent this afternoon and then higher on Thursday. 20-foot winds will be 8-12 mph this afternoon and Thursday. Wind gusts to around 25 to 30 mph are possible near convection. Most of the rain will end by Friday afternoon, with a dry forecast through the weekend and first of next week. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 88 67 86 60 / 30 70 90 50 Anniston 88 69 85 62 / 30 50 90 50 Birmingham 88 70 86 63 / 30 50 90 50 Tuscaloosa 89 71 88 64 / 30 50 80 60 Calera 88 71 86 64 / 30 50 90 60 Auburn 87 72 85 66 / 20 20 80 60 Montgomery 91 72 89 67 / 30 20 80 70 Troy 91 72 89 67 / 20 10 70 60 && .BMX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...75 LONG TERM....15 AVIATION...16