


Area Forecast Discussion
Issued by NWS Birmingham, AL
Issued by NWS Birmingham, AL
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335 FXUS64 KBMX 272311 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 611 PM CDT Thu Mar 27 2025 ...New AVIATION... .KEY MESSAGES... Updated at 608 PM CDT THU MAR 27 2025 - There is a level 2 out of 5 risk for severe storms across all of Central Alabama late Sunday night into Monday with a threat of tornadoes, damaging wind gusts, and large hail. The magnitude of the tornado threat is uncertain, but there is potential for it to increase. && .SHORT TERM... (This afternoon through Friday) Issued at 1213 PM CDT THU MAR 27 2025 A thin layer of high-level clouds are streaming across the area this afternoon, associated with mid-level shortwave troughing extending across Texas into Louisiana. A deep-layer ridge axis will shift across the area this afternoon through tonight, so stable conditions are present with warm temperatures expected as heights rise and low- level flow takes on more of a south to southwesterly heading. Expect highs in the upper 70s to lower 80s both today and tomorrow with a mix of sun and clouds. With flow shifting to the south, lows tonight will not be as cool as previous nights. Most locations will remain in the 50s. 86/Martin && .LONG TERM... (Friday night through next Wednesday) Issued at 1243 PM CDT THU MAR 27 2025 No major changes needed in the long term forecast. The main concern remains timing and evolution of the system Sunday through Monday. There have been some shifts in timing, indicating the frontal boundary may still be moving through Central AL Monday afternoon, so severe threat may continue through at least part of the day on Monday. 25/Owen Previous long-term discussion: (Friday night through next Wednesday) Issued at 322 AM CDT THU MAR 27 2025 A southern stream shortwave will continue to drift eastward along the Gulf Coast, eventually moving into Central Alabama Saturday and Saturday night. This will eventually bring high (60-70%) rain chances, but there is spread in the guidance regarding how quickly it moves in, probably related to how convection evolves over Texas the next couple days. There won`t be any surface low with this system, and while there are low chances for rumbles of thunder Saturday night, severe storms are not expected given weak instability and bulk shear. On Sunday, temperatures should warm up nicely as dry air aloft associated with an elevated mixed layer (EML) moves overhead. Guidance does indicate some scattered showers and storms during the day on Sunday. These could be strong given steep mid-level lapse rates, but deep layer shear supportive of an organized severe threat holds off until Sunday night. Guidance continues to show variability in the details of pieces of vorticity ejecting out of the northeast Pacific system eastward across the western and central CONUS. For example the latest GFS has a quicker shortwave lifting across the Midwest Sunday, while the ECMWF has a slower, negative tilt wave across the Ozarks and Mid-South Sunday evening. Both hint at another shortwave rounding the base of the trough Monday morning. These different evolutions have ramifications for the placement of one or more surface lows and associated LLJ response and surface wind direction. What is known is that a well-established warm sector will be in place across the Southeast ahead of the front with mid-60s dew points aided by Saturday`s primer wave. This along with steep mid-level lapse rates associated with an EML will contribute to MUCAPE values in excess of 1000 J/kg up to 2000 J/kg, even during the overnight period. Upper-air pattern and height falls along with deep layer shear will be favorable for supercells to move across the area after midnight Sunday night, probably eventually becoming more linear by Monday morning. The positive tilt orientation of the front could actually aid in supercells having more "room to roam" in the pre-frontal warm sector. Parameters will be favorable for large hail, damaging winds, and at least isolated tornadoes. The magnitude of the tornado threat is where the uncertainty lies. Looking at cluster analyses, there is very little overlap between the EPS and GEFS members while the GEPS members lie somewhere in between. The EPS members indicate stronger 500mb and 850mb winds than the GEFS members, as well as more backed surface winds. Also, the deterministic ECMWF indicated a more upright (north-south) convection orientation, with convection appearing to initiate on a pre-frontal trough. These mesoscale details will need to be monitored closely, as they will determine whether there is more of an isolated tornado threat vs. a more concerning overnight strong tornado threat. Tuesday looks like a quiet weather day behind the front. Another severe threat may be lurking in the Wednesday/Thursday timeframe, but ensemble spread is substantial at that time range. 32/JDavis && .AVIATION... (00Z TAFS) Issued at 608 PM CDT THU MAR 27 2025 VFR conditions are anticipated for the entire TAF period. /44/ && .FIRE WEATHER... Dry conditions continue through Friday with Min RHs around 20-30% on Friday. Rain and thunderstorms are expected to move through the area Saturday through Monday with increasing winds Sunday night as a frontal boundary moves through the area. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 51 81 57 78 / 0 10 0 20 Anniston 53 81 58 79 / 0 0 0 20 Birmingham 58 80 61 77 / 0 10 0 30 Tuscaloosa 56 82 59 79 / 0 10 0 50 Calera 56 80 60 78 / 0 10 0 30 Auburn 54 80 60 79 / 0 0 0 10 Montgomery 55 82 61 79 / 0 0 0 30 Troy 54 82 61 79 / 0 0 0 20 && .BMX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...86 LONG TERM....32 AVIATION.../44/