878 FXUS62 KFFC 191927 AFDFFC Area Forecast Discussion National Weather Service Peachtree City GA 327 PM EDT Mon Jun 19 2023 ...Morning Area Forecast Discussion... .SHORT TERM... (This evening through Tuesday) Issued at 325 PM EDT Mon Jun 19 2023 As expected, showers and thunderstorms have already fired across portions of north and central Georgia this afternoon. Most storms have been confined to mostly central Georgia thus far, but a few rumbles of thunder have been noted in some parts of north Georgia. Storms are mostly firing along a sudo-frontal/moisture boundary that is associated with the vertically stacked low slowly meandering to the southeast over portions of Kentucky and Tennessee. That low will continue to slowly work towards the CWA over the next 24-36 hours before parking itself right by us. Aloft, the upper level low has been cut off from the jet by anticyclonic rossby wave break over the northern Great Plains, which is stacking with the low to form a rex block over the eastern CONUS. As a result, rain chances will be back yet again tomorrow, as moisture continues to wrap itself around the low. Instability parameters this afternoon have picked up, especially in portions of north Georgia where MLCAPE values above 1000 J/kg are noted, but this isn't aligned the best with the moisture/shear/forcing that is more available across portions of central Georgia. Severe chances are pretty low in north GA, but can't rule out a strong storm or two. In central Georgia, where the parameter space is a bit better despite the impact of this morning's MCS, we can expect a few strong storms, some severe, with the main impacts being damaging winds with any severe storms. Also can't rule out the possibility of some large hail, isolated flash flooding, and possibly a tornado or two through the evening hours. Tomorrow has some inherent uncertainty thanks to the positioning of the upper low, which models tend to struggle with when it comes to cut-off type systems. It's likely that most everywhere will see some rain chances with the exceptions of west-central GA. However, how heavy that rain or thunderstorms may end up being will be dependent on the overall position of the low as well as some of the convective evolution this afternoon and evening. Best chances of seeing some heavier rain will be across northern and eastern GA, but that could certainly push a bit further west or south with a small jog of the low. As we continue to have repeated rounds of heavy rainfall, flash flooding will become more of a threat as the ground becomes saturated and creeks and streams less able to route away water, so please remain aware. Lusk && .LONG TERM... (Wednesday morning through next Sunday) Issued at 325 PM EDT Mon Jun 19 2023 As note in the previous forecasts the long term can be described as soggy as we see precip in the forecast through the entire long period. This wet pattern can be attributed to the closed upper low stalled over the SE that is part of a bigger omega block pattern and surface SSW flow. Both of these elements continue the support an exceedingly moist airmass. This in combination with lobes of energy rounding the base of the upper low will support continued shower and thunderstorm chances daily for much of the extended. Have maintained the usage of the word thunder given the average 1000 J/kg expected each afternoon. Currently, PWATs on the order of 1.5-1.75" are expected each day with model soundings showing a saturated profile with thin CAPE which will make for efficient rainmakers. Forecast rainfall totals continue to suggest widespread totals of 3.00-5.00" with locally higher amounts across the mountains of north GA. Given this forecast the Weather Prediction Center has some portion of the forecast area in a Slight Risk for Excessive Rainfall (Level 2 of 4) over at least the next three days. For now we have held off on a flood watch, but as local storm totals become realized there could be a need for a flood watch. For now the next seven days bear watching and the main focus is on small stream and river flooding. 28 && .AVIATION... (18Z TAFS) Issued at 159 PM EDT Mon Jun 19 2023 Another challenging forecast for ATL and surrounding sites. Currently MVFR at ATL and that should persist over the next few hours. SHRA are affecting the site and could see a rumble of thunder over the next few hours as well. Winds have gone to the SSW, and should remain on the west side for the TAF period. Speeds will be 7-12 kts today, going to 3-8 kts tonight through end of period. Cigs are expected to SCT by 00Z, but will build back end late tonight into early tomorrow morning. Some uncertainty on how low these will be - current TAF shows MVFR, but won't rule out brief period of IFR. TSRA possible again tomorrow afternoon. //ATL Confidence...18Z Update... Medium confidence cigs. High all others. Lusk && .PRELIMINARY POINT TEMPS/POPS... Athens 80 68 81 65 / 100 60 90 90 Atlanta 81 68 83 66 / 80 30 80 70 Blairsville 76 62 75 60 / 90 60 90 70 Cartersville 84 66 83 65 / 70 30 90 70 Columbus 83 69 86 66 / 100 20 60 60 Gainesville 79 68 79 65 / 100 50 90 90 Macon 83 68 85 66 / 100 40 70 60 Rome 84 68 83 66 / 70 20 90 70 Peachtree City 83 66 85 64 / 80 30 80 70 Vidalia 87 70 85 68 / 90 70 80 60 && .FFC WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Lusk LONG TERM....28 AVIATION...Lusk