032 FXUS64 KBMX 262044 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 344 PM CDT Fri Mar 26 2021 .SHORT TERM... /Updated at 0145 PM CDT Fri Mar 26 2021/ Today through Saturday. A weak stationary boundary extended across our southeast counties, supporting scattered showers and a few thunderstorms in that area today. Expect that boundary to lift northward with time as a warm front from late this afternoon through overnight tonight. The result will be gradual increasing clouds from the southeast with increasing chances for showers and a few thunderstorms. Expect the highest rain chances to become focused across the northern third of the area late tonight through Saturday with a few thunderstorms early in the day. Thunderstorm activity looks to increase later Saturday afternoon and evening across the north. Highs will be in the mid to upper 70s across the area today followed by lows in the upper 50s northeast to the mid 60s south tonight. Highs will range from the upper 70s north/northeast to the mid 80s south on Saturday. 05 .LONG TERM... /Updated at 0306 PM CDT Fri Mar 26 2021/ Saturday night through Thursday. An active upper pattern will continue into next week with several short wave trofs moving thorough the southern portions of the westerlies. A short wave trof with an associated cold front will approach northwest Alabama Saturday night. Increasing southerly low level flow on Saturday will push mid to upper 60s surface dewpoints into north Alabama. Deep layer strong shear and veering of the low level winds will also combine to pose of threat of damaging winds and isolated tornadoes late Saturday night and Sunday morning. Increased the threat level across the northwest counties to slight with a marginal risk southward to the the I-85 corridor. The tornado and damaging wind threat will decrease during the day Sunday as the low level winds veer ahead of the cold front and mid level forcing weakens. The cold front will stall out over southeast Alabama Sunday night and the rain will be confined to areas south of I-85. A short wave trof moving out of south Texas will ride along the stalled out frontal boundary and bring another round of showers and isolated storms to areas mainly south of I-20 Monday and Monday night. Locally heavy rainfall possible along and south of I-85 Monday night and Tuesday morning. Once this system moves out of the area on Tuesday, the stalled out frontal boundary will lift northward on Wednesday as a short wave trofs digs southward into the Southern Plains States. The short wave trof will push a strong cold front through Alabama Wednesday night. Could be a small threat of severe storms with this system, but too far out to include in forecast at this time. Drier and much cooler conditions on Thursday with lows in the 30s Thursday night. 58/rose Previous long-term discussion: /Updated at 0400 AM CDT Fri Mar 26 2021/ Saturday night through Sunday. Elevated showers and thunderstorms will be ongoing across the Tennessee Valley Saturday night along and ahead of a warm front which will be situated north of Central AL. Warm advection will once again overspread the Gulf coast region with dewpoints rising back into the mid to upper 60s resulting in a marginally unstable environment. This in response to a positively tilted trough over the Great Lakes region which will extend south into the Lower MS Valley with a relatively weak and elongated surface low developing over the Midwest, though the exact location varies between the models. As the surface low lifts towards the northeast, a cold front and associated showers/thunderstorms will move through our area beginning late Saturday night through Sunday afternoon. Strengthening dynamics aloft will result in eff. bulk shear values around 50-60 kts which will lead to updraft organization when coupled with around 500-1000 J/kg of MLCAPE. This would suggest the potential for a few strong to marginally severe storms, although very weak low-level lapse rates lead me to believe storms will initially be elevated as they enter our northwest counties, posing a small chance of producing damaging winds up to 60 mph and/or quarter- size hail. As storms become surface based within a marginally unstable environment (SBCAPE 500-800 J/kg) through Sunday morning, model guidance indicates shear vectors become largely unidirectional with time, suggesting damaging winds will become the primary threat with synoptic forcing decreasing throughout the day as the better kinematics quickly shift to our east. From a synoptic standpoint, the setup of a positively tilted open wave with a weakly defined surface low is not overly impressive, but will introduce a Marginal Risk of a few severe storms across the entire area from late Saturday night through early Sunday afternoon based on the parameter space discussed above. Sunday night through Thursday. PoPs rapidly decrease by Sunday evening as the cold front stalls along the Gulf Coast. Meanwhile, the development of a cutoff low over the Southern Plains is providing some forecast uncertainty for Monday, particularly in relation to its ejection across the Southeast and Tennessee Valley. Some modeling takes a more southerly path which keeps us nearly dry while a more northerly track is suggested by some guidance which results in widespread rain Monday night through Tuesday. Based on the uncertainty, kept PoPs less than 50 percent for now. The active pattern continues into midweek as another longwave trough quickly deepens over the Central CONUS and pushes another cold front into the area. As standard for this time of year, some guidance is developing a more potent parameter space which bears assessing over the next several days. 86 && .AVIATION... 18Z TAF Discussion. A frontal boundary that moved SE-ward across much of the area last night has become stationary, extending roughly from Troy to Eufaula. This boundary should return northward as a warm front tonight, reaching the I-20 corridor towards daybreak Sat. Moisture near and south of the front should bring MVFR ceilings over the area from south to north during the night. Light showers remain possible, mainly near the front as it creeps northward. CIGs reduced to IFR are likely late tonight into early Sat morning. Daytime heating and mixing should bring low MVFR CIGs south of KEET, with IFR CIGs remaining over the northern areas into the late morning. RSB / WFO HUN && .FIRE WEATHER... Clouds will increase overnight as a warm front lifts northward. The warm front will produce scattered showers and a few storms overnight. Much warmer temperatures on Saturday as increasing southerly winds brings gulf moisture northward. Most of the rain on Saturday will be north of I-20. A cold front will push southward across central Alabama on Sunday and produce numerous showers and thunderstorms. Some of the storms may become severe. No fire weather concerns due to moist ground fuels and high RH values. 58/rose && .PRELIMINARY POINT TEMPS/POPS... Gadsden 58 79 64 68 41 / 30 30 60 90 10 Anniston 60 81 66 70 44 / 30 20 40 90 20 Birmingham 62 80 67 70 45 / 30 20 60 90 10 Tuscaloosa 63 83 68 70 45 / 30 20 70 90 10 Calera 61 80 67 70 46 / 30 10 50 90 10 Auburn 63 80 65 73 49 / 40 10 10 70 30 Montgomery 65 84 68 75 51 / 50 10 10 70 30 Troy 66 85 67 79 52 / 50 10 0 70 30 && .BMX WATCHES/WARNINGS/ADVISORIES/... None. && $$