Area Forecast Discussion
Issued by NWS Birmingham, AL
Issued by NWS Birmingham, AL
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112 FXUS64 KBMX 051947 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 247 PM CDT Fri Jul 5 2024 ...New LONG TERM... .SHORT TERM... (This evening through Saturday) Issued at 1256 PM CDT FRI JUL 5 2024 A boundary will move southeast through the day today, initiating showers and thunderstorms through the afternoon and evening. Instabilities through the afternoon will be around 3000 j/kg in a few areas, with shear around 30-40 kts. Strong storms are expected with a few storms approaching severe if they can tap into the right parameters. PW values will be near max for this time of year so any activity will drop high rainfall rates. Tonight, instability weakens so any convection that lingers after sunset should be more of a shower producer with isolated thunder. The boundary is expected to push south through the night with northwest flow setting up in areas north of the boundary, bringing drier air to the northwestern half of the state at least. Saturday, models differ on where that boundary will stall, which will then determine how much coverage will occur across the state through the afternoon. Right now, will highlight areas south of I20 to have a chance for thunderstorms Saturday afternoon. Areas north of I20 should have plenty of dry air from the northwesterly flow to remain rain free. A Heat Advisory has been issued for the afternoon Saturday in the far southeast. If the boundary can make it farther Saturday morning than current models anticipate, counties included may need to be adjusted. 24 && .LONG TERM... (Saturday night through next Thursday) Issued at 229 PM CDT FRI JUL 5 2024 Deep tropical moisture will return to central Alabama through much of the long term portion of the forecast. Having said that, I do have a hard time buying into the daily likely to categorical POPs that model blend based guidance suggests each afternoon. I`ve tempered the POPs a bit each afternoon to a more climatologically realistic POP regime. Otherwise, the hot and humid conditions will continue. And we`ll have to watch where what will eventually become the remnants of Beryl end up. /61/ Previous long-term discussion: (Saturday night through next Thursday) Issued at 307 AM CDT FRI JUL 5 2024 Guidance progresses a front southward across the Deep South Saturday night, suppressing an area of tropical air characterized by PWs 2.0- 2.4", to areas south of I-20. Meanwhile, TC Beryl is forecast to emerge into the southwestern Gulf while an upper-level low swings west toward the Carolina Coast - both combating/weakening the ridge. Drier air situated to the north will coincide with surface dewpoints in the mid to uppers 60s. This effectively shifts greatest heat index values (near advisory criteria) along and south of I-85 for Sunday afternoon, and this moisture will also continue to foster diurnal showers and thunderstorms with best coverage south of I-20. The weakened presence of ridging appears to flip back early next week with medium-range guidance suggesting low- to mid-level height rises (between TC Beryl and the upper low). Tropospheric moisture begins to spread northward toward the Tennessee Valley once again. The increase in moisture/instability led to a more uniform 50-60% PoP for Monday and Tuesday afternoons despite forcing details becoming less clear. PoPs are on the decrease thereafter as the forecast becomes a little more contingent upon where Beryl decides to go. 40/Sizemore && .AVIATION... (18Z TAFS) Issued at 1256 PM CDT FRI JUL 5 2024 Scattered showers and thunderstorms will be possible across the area today through this evening. Scattered to numerous convection is moving through the state through the afternoon, with models hinting at redevelopment late afternoon and into the early evening. PW values are high so any activity over a TAF site will likely drop IFR or LIFR visibilities, though only included MVFR in TEMPO groups for now. Tomorrow, the boundary should be far enough south that only KEET and KMGM have a chance to see activity. The rest of the area should have northwest flow and drier air. 24 && .FIRE WEATHER... Hot and humid conditions will continue through the period, with scattered to numerous showers and thunderstorms each day. No high wind or low humidity impacts are expected through the period. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 72 92 69 93 / 50 20 20 40 Anniston 72 92 72 92 / 50 40 20 50 Birmingham 72 92 74 93 / 50 30 20 40 Tuscaloosa 74 94 74 93 / 50 30 10 40 Calera 73 91 74 93 / 50 40 20 40 Auburn 73 90 75 90 / 60 60 40 60 Montgomery 74 92 74 93 / 60 60 30 60 Troy 73 93 74 92 / 60 70 40 60 && .BMX WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 9 PM CDT this evening for the following counties: Autauga-Barbour-Bibb-Blount-Bullock-Chambers-Chilton- Coosa-Dallas-Elmore-Fayette-Greene-Hale-Jefferson-Lamar-Lee- Lowndes-Macon-Marengo-Marion-Montgomery-Perry-Pickens-Pike- Russell-Shelby-St. Clair-Sumter-Talladega-Tallapoosa-Tuscaloosa- Walker-Winston. Heat Advisory from 10 AM to 7 PM CDT Saturday for the following counties: Autauga-Barbour-Bullock-Chambers-Dallas-Elmore-Lee- Lowndes-Macon-Montgomery-Pike-Russell-Tallapoosa. && $$ SHORT TERM...24 LONG TERM..../61/ AVIATION...24