Area Forecast Discussion
Issued by NWS Atlanta, GA
Issued by NWS Atlanta, GA
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727 FXUS62 KFFC 050810 AFDFFC Area Forecast Discussion National Weather Service Peachtree City GA 410 AM EDT Wed Jun 5 2024 ...Morning Area Forecast Discussion... .SHORT TERM... (Today through Thursday) Issued at 404 AM EDT Wed Jun 5 2024 500 mb analysis reveals several vort maxes within the overall shortwave-troughing pattern over the Southeast. Isolated to scattered showers and a few thunderstorms have been occurring across portions of the CWA overnight amid the humid, weakly-forced environment, as well as upstream across portions of AL. Will likely see isolated showers continue through the remainder of the morning hours. Additionally, areas of fog have developed across portions of north GA, with dense fog in portions of Gwinnett, Barrow, Jackson, and Hall Counties. These vort maxes will shift eastward through the day, and with the help of daytime heating, scattered showers and thunderstorms are expected this afternoon and evening. SREF progs MUCAPE reaching 1000- 1500+ J/kg and hi-res models prog mid-level lapses of 6.5 to near 7 deg.C/km, so updrafts should have no problem getting going. That said, 0-6 km bulk shear generally less than 30 kts will limit storm organization/intensity. SPC has the entire CWA outlooked in a General Thunder risk, which makes sense, as the aforementioned ingredients suggest the possibility of a few strong storms (with locally heavy rainfall, frequent lightning, gusty winds, and small hail) but not much of a severe weather (damaging wind and large hail) threat. Any slow-moving storms or back-building storms that are especially efficient rainfall-producers could cause localized flooding, especially across north GA, where flash flood guidance is lower and soil moisture is greater. As the shortwave axis shifts eastward over the CWA overnight, scattered showers and thunderstorms will continue. HREF and hi-res models suggest decent instability (500-1000 J/kg) and mid-level lapse rates of 6.5 to 7.5 deg.C/km, so the potential for a few strong storms will persist overnight. The flow aloft will become northwesterly tomorrow (Thursday), and at the surface, a weak front will push into north GA. The day will start off with essentially CWA-wide 30% to 50% PoPs, with PoPs becoming maximized (60% to 70%) mainly along and south of I-20 in the afternoon and evening, ahead of the front where instability and PWAT will be greatest. SPC has the entire CWA outlooked in a General Thunder risk again tomorrow, which makes sense given these ingredients plus little to no 0-6 km bulk shear. A few strong storms will be possible with the aforementioned hazards, especially across central GA, where mid-level lapse rates are progged to be 6.5 to around 7 deg.C/km. As far as temperatures go, morning lows will be in the mid-60s to lower 70s, and afternoon highs will be in the lower 80s to around 90. Martin && .LONG TERM... (Thursday night through Tuesday) Issued at 404 AM EDT Wed Jun 5 2024 The long term period starts off with a bang, as a double-barreled cold front sweeps across the area Thursday night. Shower and thunderstorm activity is forecast to be shunted SE by the initial front, with isolated to low end scattered activity SE of Macon Thursday evening. Cooler air will filter into the area behind the secondary front. As a result, Friday morning lows will only be about 3 to 5 degrees cooler than Thursday morning`s. With more sunshine Friday versus Thursday, Friday`s high temperatures will be a bit warmer. However, minimum relative humidity values Friday afternoon will be a full 30% lower than on Thursday. As a result, Friday will feel more comfortable. The big story will be lows Saturday morning. Forecast daybreak temperatures will range from the mid 50s in the NE mountains to the mid 60s in the extreme SE portion of the County Warning Area. Due to the urban heat island effect, lows in the Atlanta metro will be in the lower 60s, but some of the suburbs will drop into the upper 50s. Dry air on Saturday will continue to make temperatures more bearable. After a brier warm-up, another upper level trough and associated surface front will approach the area from the NE late in the weekend. Showers and thunderstorms ahead of the front will enter NE GA late Saturday night, with precipitation spreading across the remainder of the area on Sunday. The best chance of rain will be Monday afternoon across the S portion of the area as the front works on daytime instability. Rain will come to an end behind the front from the NW late Monday night and Tuesday, as drier and slightly cooler air filters in. /SEC && .AVIATION... (06Z TAFS) Issued at 143 AM EDT Wed Jun 5 2024 Have VCSH at all TAF sites except CSG at some point for the remainder of the overnight as there are iso`d SHRA and TSRA across N and central GA. MVFR/IFR cigs (possibly LIFR at AHN) look to spread over AHN and the ATL area sites between 08z-10z and persist until 14z-15z. AHN may also have MVFR/IFR vsby restrictions. Sct`d Cu field is expected this afternoon along with iso`d/scat`d SHRA and TSRA (covered by a PROB30 at all sites). Winds will be SSW to SW at 5-10 kts. //ATL Confidence...06Z Update... Medium confidence on morning cigs and timing/coverage of SHRA/TSRA. High confidence on all other elements. Martin && .PRELIMINARY POINT TEMPS/POPS... Athens 86 69 85 66 / 40 40 40 10 Atlanta 86 71 86 68 / 40 50 50 10 Blairsville 78 65 80 60 / 50 50 50 10 Cartersville 85 68 86 64 / 50 50 40 10 Columbus 90 72 86 70 / 30 50 60 10 Gainesville 82 69 85 66 / 50 50 40 10 Macon 88 71 86 69 / 30 40 70 10 Rome 86 69 87 65 / 50 50 30 0 Peachtree City 87 69 87 66 / 40 50 50 10 Vidalia 90 72 89 71 / 30 40 70 30 && .FFC WATCHES/WARNINGS/ADVISORIES...None. $$ SHORT TERM...Martin LONG TERM....SEC AVIATION...Martin