Area Forecast Discussion
Issued by NWS Atlanta, GA

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000 FXUS62 KFFC 221920 AFDFFC Area Forecast Discussion National Weather Service Peachtree City GA 320 PM EDT Thu Jun 22 2017 .SHORT TERM /Tonight through Friday Night/... Main forecast concern will be initially here in the near term as the environment has shown some rapid destabilization with the extremely tropical airmass in place as the low cloud deck has been scattering quickly from the south given being in the warm sector of Cindy`s remnants. Convective bands streaming in from the south fueled by a steady strong moisture advection off the Gulf will have about 2000- 3000 J/kg of SBCAPE to attain, albeit tall/skinny in profile. The issue will be with both the PWATs being close to 2 inches and enhanced area of helicity rich low levels just starting to impinge upon the western border of the CWA. Some 250 m2/s2 of 0-1 km SRH will be bothersome for isolated quick spin-up tornado potential in our western tier from late afternoon here into the evening. Also given the aforementioned PWATs, any stronger convection will have high precip efficiency and training of cells could bring flash flood potential. It`s not a welcomed sight to see temps of upper 80s/low 90s over dewpts in the mid to upper 70s advecting into the area. The deeper moisture field and orientation of Cindy`s dynamics should continue to phase with an upper shortwave more to the NW by late tonight into Friday. Expecting a lull in shower/storm coverage mainly after midnight tonight as chance to likely pops stay more orientated to the far NW and TN Valley. Could have a similar type of convective threat for northern portions of the area by Friday afternoon (given progged instability/low level shear parameters) and then be more progressive to the SE with the evolution of the shortwave and translated sfc front late Friday night into Saturday. Tailored likely to categorical pops with this feature accordingly across north GA. Will be rather gusty out of the SW ahead of this as well. Temp wise, a bit more diurnal range expected Friday with more areas reaching highs close to climo in the upper 80s to low 90s (less morning cloud coverage expected). Baker .LONG TERM /Saturday through Thursday/... The remnants of Tropical Storm Cindy will finally be out of our hair at the beginning of the long term forecast period on saturday morning. However there will be a cold frontal boundary moving south across the area. Rain and thunderstorms will be ongoing along the front...enhanced by diurnal heating in the afternoon. There looks to be enough deep layer shear /0-6km of 20-30kts/ as a broad trough deepens across the eastern 2/3rds of the US to work in conjunction with instability invof the front. This should allow for some organization of thunderstorm clusters along the front. The main threat will be damaging wind gusts. SPC has a large majority of central and eastern Georgia in a marginal risk. The front will make slow progress into central Georgia Saturday evening into the overnight hours but the loss of daytime heating and rather poor forcing should allow most activity to gradually dissipate. Front looks to linger across far southern zones on Sunday where again diurnal heating should allow for a gradual increase in thunderstorm activity through the afternoon. Shear appears to be displaced too far north to pose a notable severe threat by this time. Can`t rule out isolated stronger storms...but think Saturday has better parameters than Sunday. Front should clear the CWA by Monday. A rather unseasonably strong area of sfc high pressure will gradually build into the region from the north in the wake of the front...which will make for a dry day. A strong shortwave rotating around the broad scale trough over the eastern US will likely bring some clouds to area on Tuesday...but thinking large dome of sfc high pressure will keep things dry. Height rises in the mid level behind this shortwave combined with sfc high pressure should make for a very pleasant Wednesday. Will see moisture gradually return outside of the extended as the sfc high begins to scoot off the Atlantic Coast. Kovacik && AVIATION... 18Z Update... Cigs primarily in MVFR to low end VFR range to start this period, then could see some scattering of higher VFR with isolated to scattered SHRA/TSRA this afternoon into evening. Some stronger SSE winds and gusts could be mixed down with areas of scattering as well or within convection. Have tempo for TSRA mainly from 20-00z with slight timing differences for most sites. Could again see overnight with IFR/MVFR cigs and switch to SSW winds mainly after 07-09z for KATL and nearby sites. Should have a lull in precip overnight into Friday morning (staying more NW of sites). Though included prob30 for TSRA after 18z Friday at KATL. Wind mags increase also by then to 11-13 kts with gusts near 20 kts. //ATL Confidence...18Z Update... Medium on precip coverage/timing into this evening. Medium on overnight cig potential lower than MVFR. High on all else. Baker && .PRELIMINARY POINT TEMPS/POPS... Athens 71 90 73 85 / 60 30 60 70 Atlanta 72 87 73 83 / 60 40 70 70 Blairsville 67 83 68 79 / 70 60 80 70 Cartersville 72 87 72 83 / 60 60 80 70 Columbus 74 90 75 86 / 20 20 40 60 Gainesville 70 86 72 82 / 60 40 80 70 Macon 73 91 74 88 / 30 20 30 40 Rome 72 87 72 84 / 60 70 80 70 Peachtree City 71 88 72 84 / 50 30 60 60 Vidalia 75 91 75 91 / 40 20 20 30 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Baker LONG TERM....Kovacik AVIATION...Baker

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