Area Forecast Discussion
Issued by NWS Birmingham, AL
Issued by NWS Birmingham, AL
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231 FXUS64 KBMX 221809 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 109 PM CDT Wed May 22 2024 ...New SHORT TERM, AVIATION... .SHORT TERM... (This afternoon through Thursday) Issued at 107 PM CDT WED MAY 22 2024 A couple rounds of thunderstorms will pass within close proximity to the northwestern portions of Central Alabama over the next 24 hours as a northeast to southwest oriented cold front slowly drifts towards the Mid-South region. The mid-level ridge axis has shifted east of the area allowing low-level flow to take on more of a south to southwesterly heading. Deeper moisture still resides to our west, so our dewpoints will mix down into the lower to mid 60s this afternoon and again tomorrow while lower 70s dewpoints are forecast over northern Mississippi and the Tennessee Valley. The first wave of thunderstorms will likely follow the more favorable instability gradient as it moves along the frontal zone, staying north of the forecast area and moving from Mississippi into northern Alabama this afternoon. A second wave will have improved upper-level support overnight as a shortwave begins to pass across the area. Some weakening thunderstorms will move in across the northwest around midnight, but QPF amounts look minimal. Same story on Thursday as the front remains well to our north. Most of the activity will remain north of Central Alabama during the day, and any isolated shower or storm is not expected to be strong as a result of limited forcing and instability. Expect mostly sunny conditions with highs in the mid to upper 80s. 86/Martin && .LONG TERM... (Thursday night through next Tuesday) Issued at 315 AM CDT WED MAY 22 2024 A southern stream shortwave remains forecast to move across the Tennessee Valley Friday morning. This will likely be accompanied by a weakening thunderstorm complex to our north, so chances for showers/storms remain in the forecast for our northern half. The perturbation is progged to advance into the Appalachians mid to late morning. Thus, convective coverage during the afternoon may not be too high considering the background effects of the low- amplitude ridge in the region. Latest guidance suggests the ridge sill strengthen a bit on Saturday, though both moisture & instability values climb ahead of a stalling cold front laying over to our north. Forecast soundings from the GFS/ECMWF both show modest mid-level lapse rates with ~30 kts eff. bulk shear. MLCAPE of 2,000-3,000 J/kg is progged with dewpoints in the low 70s. Thus, any convective development during the afternoon could be strong, and we`ll need to keep an eye out for severe weather once mesoscale details can be sorted out. rebound Subsequent disturbances will impacts regions to our northwest on Sunday, with a notable system moving from the Plains toward the Midwest. Meanwhile, we`ll remain hot/humid with at least a scattering of showers/storms across the northern half of Central Alabama. There`s disagreement on timing, but medium-range guidance depicts stormy weather associated with a frontal passage in our area Monday/Tuesday. Cooler, more stable weather would follow. 40/Sizemore && .AVIATION... (18Z TAFS) Issued at 107 PM CDT WED MAY 22 2024 A scattering of low-level cu have developed again this afternoon, but another period of VFR conditions is expected. High pressure extends along the East Coast into the northeastern Gulf of Mexico, so surface winds are out of the south around 5 to 10 kts. Winds will go calm tonight, and high-level cloud cover will increase across the area. 86/Martin && .FIRE WEATHER... High pressure will be in control through Thursday. Min RH values this afternoon and Thursday 45 to 50 percent. 20 foot winds will be generally 4 to 6 mph from the south. Max RH levels tonight will be above 90 percent. Next chance for wetting rain Thursday night across the northwest, with chances for rain across the northern counties on Friday. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 66 88 65 87 / 10 20 20 40 Anniston 67 88 67 87 / 10 10 10 30 Birmingham 70 89 70 88 / 10 10 10 30 Tuscaloosa 69 89 70 90 / 10 20 10 20 Calera 69 88 68 88 / 10 10 10 20 Auburn 68 87 68 86 / 0 0 0 10 Montgomery 68 89 69 91 / 0 0 0 10 Troy 66 89 68 90 / 0 0 0 10 && .BMX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...86/Martin LONG TERM....40 AVIATION...86/Martin