Area Forecast Discussion
Issued by NWS Birmingham, AL
Issued by NWS Birmingham, AL
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295 FXUS64 KBMX 131052 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 552 AM CDT Mon May 13 2024 ...New AVIATION... .SHORT TERM... (Today through Tuesday night) Issued at 240 AM CDT MON MAY 13 2024 A positively-tilted trough is currently situated across the Plains with at least 3 embedded vort maxes evident near Kansas on water vapor imagery. This disturbance will continue east toward the Mid Mississippi River Valley today and tonight. Meanwhile, a mainly zonal 500 mb flow is situated across the Gulf Coast, sitting atop a low amplitude ridge across the Gulf of Mexico. A broad zone of isentropic ascent is analyzed across the Lower Mississippi Valley where southerly 850 mb flow is situated. This is associated with ongoing showers & thunderstorms overspreading much of central MS, with light rain showers now developing across AL this morning. Convective activity will continue to drift eastward with a MCS progged to impact southern AL by mid this morning. Despite 50-60 kts of 0-6 km bulk shear, SBCAPE remains pinned along the I-10 corridor. This will keep severe threats suppressed to our south, and there`s not much indication of low-level recovery throughout today in latest guidance. As such, severe threats have been trimmed southward, and latest QPF through tonight has had a similar response. A low-end severe threat will be maintained in impact graphics, mainly for the southern half of the area through ~Noon. Additionally, some convective allowing models are suggesting non-thunderstorm wind gusts above 40 mph this morning in response to a potential wake low/pressure gradient. We`ll need to monitor for that. By tomorrow the upper-level disturbance is forecast to continue east closer to the TN and OH Valleys. Another wave of coastal convection is expected to advance east toward Florida during the morning. This will allow for some clearing skies and recovering instability during the afternoon as temperatures warm into the lower 70s/mid 80s across Central AL. Forecast soundings suggest colder temperatures aloft as the disturbance approaches. MLCAPE <2,000 J/kg is possible with 40- 50 kts eff. bulk shear. Thunderstorms developing during the afternoon will have the opportunity to produce hail, some at or above 1", as well as a few damaging wind gusts considering DCAPE 800- 1,100 J/kg. Thus, the low-end severe threat for hail/wind remains in place across the whole forecast area. Activity will wane after sunset with drier air moving in from the west on the back side of the departing trough. 40/Sizemore && .LONG TERM... (Wednesday through next Sunday) Issued at 240 AM CDT MON MAY 13 2024 The main trough slides through the area and a weak shortwave will slide along the backside of the trough across the northern portions of the area. With it moving through during the daytime there will be a chance of isolated to scattered showers with a few rumbles of thunder, through the afternoon hours on Wednesday. Dry weather on Thursday, with the next system approaching the area from the southwest late Thursday afternoon, with increasing rain chances overnight Thursday night. Showers and storms will become widespread on Friday with quite a bit of rain expected. Some model differences right now on how many rounds of moderate to heavy rain we can expect, but right now we may see 1 to 2 inches from Thursday night through Friday night, with locally higher totals, especially in the south. Wet conditions may linger into Saturday, but most of the heavier activity will be south of the area. After Saturday, models are all over the place with another shortwave moving through or high pressure setting up, so will go with climate for Sunday. 16 && .AVIATION... (12Z TAFS) Issued at 546 AM CDT MON MAY 13 2024 Rain has become widespread across Central Alabama airfields. This will continue, with some TSRA potential at MGM/TOI this morning. perhaps some MVFR vis due to rain. There will also be wind gusts on the back edge of the rain, ~25 kts or so according to latest guidance and obs out of eastern MS. Cigs remain VFR at this time, though I`ve maintained MVFR cigs in TAFs throughout much of today to remain aligned with guidance. Winds will remain easterly to southeasterly at 5-10 kts with the higher gusts. Most of this convection will exit the area later this morning, and there could be a period where conditions dry out this afternoon. However, additional convection moves back into the area after ~06z, with highest confidence of TSRA once again at MGM/TOI. This was handled with PROB30s for now. IFR cigs are forecast at all terminals after ~03z regardless. 40/Sizemore && .FIRE WEATHER... Rain with embedded thunderstorms will overspread Central Alabama this morning and continue on and off through Tuesday afternoon, before dissipating in coverage Tuesday night. 20 ft winds will be southeast 7-10 mph today with Minimum RH values at 70-75 percent. 20 ft winds on Tuesday will be west-southwest at 7-10 mp with Minimum RH values at 60-70 percent. Isolated to scattered showers/storms will be possible Wednesday afternoon across the northeastern areas. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 71 63 80 60 / 90 60 80 40 Anniston 72 63 79 62 / 90 60 80 40 Birmingham 72 65 80 63 / 90 60 70 30 Tuscaloosa 74 66 83 63 / 90 60 70 10 Calera 72 65 80 63 / 90 60 70 20 Auburn 72 65 79 64 / 90 60 70 30 Montgomery 76 67 83 64 / 100 70 70 20 Troy 76 66 82 65 / 90 70 70 20 && .BMX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...40/Sizemore LONG TERM....16 AVIATION...40/Sizemore