471 FXUS62 KFFC 201508 AFDFFC Area Forecast Discussion National Weather Service Peachtree City GA 1108 AM EDT Sat Jul 20 2019 .UPDATE... Heavy rain and thunderstorms are ongoing across far northwestern Georgia. With high PWATs in excess of 2 inches and very slow boundary layer winds, this precipitation has been nearly stationary over this area for several areas, which has warranted a Flash Flood Warning in the area. PoPs in this area have been significantly increased as a result. Elsewhere in the area, showers have begun to develop near the Atlanta metro area along with some isolated showers across north Georgia. Scattered to numerous thunderstorms are expected to develop in the afternoon hours, especially across western Georgia. Otherwise, only minor adjustments have been made based on the latest observations. King && .PREV DISCUSSION... /Issued 750 AM EDT Sat Jul 20 2019/ UPDATE... 12z Aviation update below. Baker PREV DISCUSSION... /Issued 416 AM EDT Sat Jul 20 2019/ SHORT TERM /Today through Sunday/... Regime should stay fairly similar thru weekend as a broad/weak low pressure and associated enhanced moisture field persists across the northern Gulf states with very slow westward propagation. Have likely pops in the west/north with chance elsewhere given the better moisture axis. With PWATs near 2 inches in this area we could have some isolated flash flooding potential with stronger convection and cannot rule out a few with strong/damaging winds from enhanced downdrafts. Thermal profiles progged to again have tall/skinny CAPE so not expecting much of a hail threat with any stronger storms. Have a bit lower pops for Sunday given more shifted aforementioned low/moisture to the west, but still have 20 to 30 percent most areas and 40 to 50 pops in the far north/NW. Temps look to be right around climo norms with highs in upper 80s to low 90s (a bit higher in parts of the east). Heat indices for now look to stay below advisory level in that area but could make it into the low 100s. Baker LONG TERM /Sunday Night through Friday/... Main concerns in long term period continue to be timing for convection and likelihood that front will push through CWA next Tuesday/Wednesday. Model guidance still indicating large elongated upper ridge will be replaced by more amplified pattern with high amplitude ridge over the western CONUS and upper trough over the east half. Prior to and during this transition, noticeable weakness in the upper ridge will remain just to our west with deep moisture and slightly cooler mid level temps. Convection coverage may decrease a bit at start of long term period on Monday with slightly drier air moving in from the east. However as shortwave and front approach from the NW, moisture from weakness gets pooled ahead of front so expect more widespread convection on Tuesday. Guidance blend PoPs nearing categorical which matches well with neighboring WFOs. Can't rule out chc of slightly more organized strong/severe storms on Tuesday as well tho abundant clouds and lingering stratiform precip in the morning may significantly limit afternoon heating and instability. Heavy rain also likely in this pattern but hopefully mean winds aloft and vertical wind shear will be sufficient to keep storms moving and not remaining in any one place for too long. Models in better agreement on how far front will push but still skeptical based on subjective knowledge of fronts making it that far south in July. Guidance not going too crazy with cooler/drier air at the surface so only small modification to model blend temps/ dewpoints. Did adjust PoPs a bit to keep slight chc and TSRA lingering longer behind front based on uncertainty mentioned earlier. SNELSON AVIATION... 12Z Update... VLIFR/LIFR cigs mainly 200-400 ft this morning then gradual lifting/scattering after 13-15z. Area of showers and isolated TS possibly pushing across the sites near ATL initially so have most locations with VCSH. Cu field today 3-4 kft with more widespread SHRA/TSRA again mainly 18-00z. Winds generally SW 3-7 kts through period with higher mags in afternoon and possible VRB gusts with any TSRA. //ATL Confidence...12Z Update... Medium on overall cig trend and precip coverage. High on all else. Baker && .PRELIMINARY POINT TEMPS/POPS... Athens 93 72 92 73 / 40 20 30 20 Atlanta 90 73 89 73 / 60 30 30 20 Blairsville 86 67 83 66 / 70 40 40 30 Cartersville 91 70 90 71 / 60 40 30 30 Columbus 92 73 92 73 / 60 20 30 20 Gainesville 90 72 89 72 / 60 30 30 20 Macon 94 73 94 73 / 40 20 20 20 Rome 92 71 90 72 / 100 40 40 30 Peachtree City 91 71 90 72 / 60 30 30 20 Vidalia 96 74 95 74 / 30 20 30 20 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...King LONG TERM....BDL AVIATION...King