Area Forecast Discussion
Issued by NWS Atlanta, GA
Issued by NWS Atlanta, GA
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
230 FXUS62 KFFC 270748 AFDFFC Area Forecast Discussion National Weather Service Peachtree City GA 348 AM EDT Thu Jun 27 2024 ...Morning Area Forecast Discussion... .SHORT TERM... (Today through Friday) Issued at 346 AM EDT Thu Jun 27 2024 At a glance: - Chances for afternoon thunderstorms today and tomorrow - Brief reprieve from highs in the 90s for western Georgia An impressive airmass change is underway, led by a mid-level shortwave swinging across the Southeast, and moist southwesterly flow off of the open Gulf. PWATs on yesterday`s 26/12Z sounding were approximately 0.9" (just below the 10th percentile per SPC`s sounding climatology) and are forecast to balloon to 2" or higher by early afternoon today -- approaching and potentially exceeding daily climatological maximums. With a substantial increase in moisture, and lift provided by a cold front that will slowly be nudged across the forecast area by the movement of the aforementioned shortwave, north and central Georgia`s best rain chances in several days will come today and carry through tomorrow. Showers and isolated thunderstorms will initially be relegated to northwest Georgia through the morning, but will spread southeastward with afternoon heating, with scattered to numerous thunderstorms then possible until sunset. Thermodynamic profiles aloft are fairly weak (still evidence of multiple weak capping versions above the mixed layer on the 27/00Z sounding), so not expecting widespread severe chances by any means. However, with a quasi-tropical airmass in place, water-loaded downdrafts on an especially strong upward pulse may be able to produce damaging wind gusts on the way down. A Marginal Risk has been analyzed across the southern half of the area by the Storm Prediction Center to highlight the potential for an isolated downburst. Mid-level flow weakens moving into Friday, but moisture remains in place, so expect much the same to round off the work week: diurnally- driven convection peaking in the afternoon, with a low but non-zero chance of an isolated strong to marginally severe storm. Our surge in moisture will be counteracted by a decrease in high temperatures today, most substantial across the northern half of the area where cloud cover will be thickest. Highs will top out in the mid-to-upper 80s north of I-85, and in the mid-90s elsewhere. On Friday, much of the area will creep back into the 90s, aside from the terrain of northeast Georgia which will remain in the upper-70s to lower-80s. 96 && .LONG TERM... (Friday night through Wednesday) Issued at 346 AM EDT Thu Jun 27 2024 Broad upper level ridging is expected to be in place over much of the eastern CONUS as the period begins on Friday night, and persist into the weekend. A more typical summertime pattern is expected underneath this pattern, with diurnally-driven convection leading to thunderstorms each afternoon across the area. Dewpoints in the low to mid 70s and precipitable water values increasing to 1.8 to 2 inches will be sufficient to warrant scattered to numerous coverage across the area each day, with PoPs ranging from 45-65 percent across the area each afternoon. Aside from high temperatures in the 80s in the higher elevations of far northeast Georgia, highs are forecast to be in the low to mid 90s on Saturday, and will climb a couple of degrees across the area on Sunday afternoon. These highs, combined with the aforementioned dewpoints in the 70s, will contribute to heat index values in the triple digits across the much of the forecast area through the weekend. Many locations, particularly south of I-85, could see heat indices in excess of 105 which would warrant heat headlines each day. Late Sunday into early Monday, a low pressure system over southeast Canada will extend a weakening cold front into the Tennessee Valley region, which will provide a focus for additional thunderstorms as it advances southward through the forecast area. Drier air will attempt to build into north Georgia as northwesterly flow filters into the area behind the frontal boundary. Dewpoints are forecast to briefly drop into the 60s in north Georgia behind the frontal boundary on Monday and Monday night. In any case, scattered afternoon thunderstorms will develop once again on Monday afternoon, although highest chances will be focused in central Georgia where higher dewpoints remain. Upper level ridging will set up over the region once again by Tuesday. Meanwhile, easterly to southeasterly flow will bring in additional low level moisture, ensuring the relatively drier conditions in north Georgia will be short-lived. Hot, humid conditions and diurnal thunderstorms are thus expected to continue through midweek. King && .AVIATION... (06Z TAFS) Issued at 144 AM EDT Thu Jun 27 2024 Conds to deteriorate through the morning. Cigs initially 10kft or higher will drop to BKN low-VFR by 14-15Z with arrival of wave of moisture. -TSRA will be possible (and likely at times) over a broad window spanning 18-02Z, currently captured by both a TEMPO and PROB30 group. Impacts most probable to northern terminals between 18-22Z. MVFR vsbys psbl during heaviest pcpn. Winds will be out of the W side (WNW to SW) at 5-6kts through early aftn, swinging to the SE by 22-23Z... again at 6kts or less. Nonzero chc of low- MVFR to IFR cigs Friday morning. //ATL Confidence...06Z Update... Medium confidence all elements. 96 && .PRELIMINARY POINT TEMPS/POPS... Athens 91 71 90 72 / 50 40 40 50 Atlanta 89 72 90 74 / 60 40 40 30 Blairsville 83 67 84 69 / 50 30 60 40 Cartersville 88 70 91 73 / 60 30 40 30 Columbus 91 73 92 74 / 50 40 50 30 Gainesville 87 72 87 73 / 50 30 40 40 Macon 94 72 92 73 / 60 30 50 20 Rome 88 71 92 74 / 50 30 40 20 Peachtree City 89 71 91 72 / 60 30 40 30 Vidalia 96 75 94 75 / 50 40 70 30 && .FFC WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...96 LONG TERM....King AVIATION...96