Area Forecast Discussion
Issued by NWS Atlanta, GA
Issued by NWS Atlanta, GA
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924 FXUS62 KFFC 071059 AFDFFC Area Forecast Discussion National Weather Service Peachtree City GA 659 AM EDT Sun Jul 7 2024 ...New 12Z Aviation Discussion... .SHORT TERM... (Today through Monday) Issued at 440 AM EDT Sun Jul 7 2024 Key Messages: - Diurnally driven convection will impact much of north and central GA Sunday and Monday. Severe weather is not expected. A few strong storms could occur. - Heat advisory has not been issued for today, but it will still be hot and humid. Heat indices will rise to the low 100s in many locations before afternoon storms provide some relief. Forecast: Rainfall and thunderstorms have come to an end this morning in most locations. Main problems will be haze and developing fog in some locations. This should be patchy through sunrise, but we are already seeing some impacts in and around the metro and some surrounding locations. If trends continue, SPS for patchy dense fog may be issued. CWA is stuck in the middle between a cut off low to the east and Tropical Storm Beryl to the west. Flow at the surface will be from the south to southeast, allowing tropical moisture to continue to filter into Georgia between these two features as the surface boundary that moved in yesterday continues to slowly retreat back to the north. PWATs remain well in excess of 2", surface dewpoints are well into the 70s in all but far N GA, and day time heating continues to bring temperatures well into the 90s. Put all that together, and you`ve got a set of miserable Georgia summer days. Diurnal convection will continue both today and tomorrow. The good news is this will likely limit afternoon heating to an extent - heat indices are expected to remain below advisory thresholds thanks in part to afternoon storms and cloud cover/convective debris. Still, they will rise into the low 100s in many locations. Given we`ve seen numerous days in a row of unusual heat (even for July), please continue to use caution if spending time outdoors. Storms look to be pretty typical for summer, and severe weather is not expected, though will never rule out a strong to severe wind gust that could bring down a few trees in Georgia this time of year. Afternoon CAPE values are forecast to be 1500-2500 J/kg, and CAPE profiles are tall but skinny thanks to poor mid and upper level lapse rates given our moist environment. Shear remains poor as upper level jet remains well to the north. Bigger concern from storms will be rainfall. Lack of shear means little motion to storms that do form, and tropical moisture in place will make for very efficient rainfall producers. Storms yesterday regularly showed 1-2+" an hour rainfall rates, which can lead to localized flooding or even flash flooding in some locations. Lusk && .LONG TERM... (Monday night through Saturday) Issued at 440 AM EDT Sun Jul 7 2024 The forecast area will initially remain entrenched in a humid and summerlike airmass to start the extended forecast period as we remain on the western periphery of the Atlantic subtropical ridge. Meanwhile, model agreement is increasing regarding the eventual track of the remnants of Beryl, which by Tuesday afternoon are expected to be lifting from the Mid-Mississippi Valley into the Ohio Valley to our northwest. Based on this forecast, no direct Beryl impacts are anticipated locally, and diurnally-enhanced scattered convection can be anticipated again on Tuesday. Beyond Tuesday, things look to be trending drier as compared to previous forecast iterations. With the track of Beryl`s remnants more likely to pass well to our north into the Ohio Valley and toward the Great Lakes region, enhanced moisture associated with the lingering circulation would bypass the area, and drier air would instead wrap south of the system. As such, PWATs would be more likely to drop into the 1 to 1.5" range, at least in the northwest half of the area, from Wednesday to Friday as compared to early week 2+" values. PoPs have thus been adjusted lower during the latter half of the work week, mainly into the chance range, with the higher PoPs shunted into the southeastern half of the area. Temperatures will remain hot with highs ranging from the low to mid 90s through the week. However, if the aforementioned drier airmass trend is realized, heat index values would begin to trend downward a bit by midweek with 100+ degree values diminished and focused farther southeast. RW && .AVIATION... (12Z TAFS) Issued at 655 AM EDT Sun Jul 7 2024 Low cigs are plaguing TAF sites this morning, with IFR/LIFR bouncing around ATL and several other sites completely socked in. Vsbys have also occasionally moved MVFR. This will continue until approx 14Z where sun should burn off low cigs/vsbys. Afternoon diurnal TSRA expected at all sites. Tomorrow morning, low cigs again possible, though details may be dependent on locations that receive most rainfall today, so some uncertainty. Winds will be from the E to SE, but light at 3-8 kts. //ATL Confidence...12Z Update... Medium cigs tomorrow morning. High all others. Lusk && .PRELIMINARY POINT TEMPS/POPS... Athens 73 91 73 95 / 50 70 30 50 Atlanta 75 93 75 94 / 40 70 30 50 Blairsville 69 87 69 88 / 40 80 30 60 Cartersville 73 94 73 95 / 30 70 20 50 Columbus 76 94 75 95 / 40 70 20 50 Gainesville 74 91 74 93 / 40 70 20 50 Macon 75 92 75 95 / 40 70 20 50 Rome 74 95 74 95 / 30 60 20 50 Peachtree City 73 93 73 95 / 40 70 30 50 Vidalia 75 92 75 92 / 40 70 20 70 && .FFC WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Lusk LONG TERM....RW AVIATION...Lusk