Area Forecast Discussion
Issued by NWS Atlanta, GA
Issued by NWS Atlanta, GA
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781 FXUS62 KFFC 071050 AFDFFC Area Forecast Discussion National Weather Service Peachtree City GA 650 AM EDT Tue May 7 2024 ...New 12Z Aviation Discussion... .SHORT TERM... (Today through Wednesday) Issued at 336 AM EDT Tue May 7 2024 500mb analysis shows nearly zonal flow across the CWA this morning. Shortwave ridging is expected to build today, but quickly return to a more zonal pattern on Wednesday. At the surface, high pressure will remain in place. A weak surface boundary will remain well north of the area. Models continue to struggle with the pattern in place, with most of the forcing within the mid or very upper levels of the atmosphere for much of the SE US. With the shortwave ridging in place for much of today, convection should be fairly limited. Models have been consistent with isolated to scattered convection developing very late in the afternoon/early evening across portions of north central AL and moving into north GA. This activity seems to be related from a possible outflow boundary in association with convection that is currently well to the west of here. The solution seems reasonable, but his highly dependent upon the evolution of what goes on out west. There will be enough instability to work with and lapse rates will be fairly steep, if the convection/outflow can survive and make it this far to the east. Wednesday seems to be the more active of days for the CWA. The flow in the mid levels will go back to a more zonal pattern. In addition, there will be coupled jet structure aloft to potentially provide some widespread lift in the very upper levels. This activity is also dependent upon organized convection that develops out west and moves east. There is an axis of good instability and steep lapse rates, especially across northern portions of the state. Not confident enough to go likely pops, but high chance should suffice for now. Good instability and steep lapse rates will persist this evening and through Wednesday. There is some potential for isolated severe storms, with the primary hazards being damaging winds and large hail. NListemaa && .LONG TERM... (Wednesday night through Monday) Issued at 336 AM EDT Tue May 7 2024 An ongoing potentially active weather period will characterize the start of the long term forecast Wednesday night into Thursday morning. Convection, some likely severe, will be in progress somewhere across the Tennessee Valley in the form of one or multiple MCSs Wednesday night. This activity should gradually progress east- southeastward in the well in advance of the surface cold front through Thursday morning. Models tend to struggle in this type of environment regarding the placement/timing of convection, so a significant degree of uncertainty does remain. With that said, in general PoPs will be on the increase across north Georgia from late Wednesday night into Thursday morning with some associated severe potential also increasing through this time. Given 0-6 km bulk shear values of 40-50+ knots, damaging wind gusts would be the primary concern with any convective complex that could enter north Georgia with large hail and perhaps an embedded brief spin- up tornado threat as well. To highlight this potential, SPC has maintained a Slight Risk for far north Georgia and a Marginal Risk down to roughly I-20 for the late Day 2 period from late Wednesday night into early Thursday morning. As we head later in the day on Thursday, the surface cold front will begin to approach and push into the area. The front will get its most sustained push into the area by Thursday afternoon as the upper trough deepens across the Great Lakes. Additional convection will likely develop in advance of the front by Thursday afternoon, though coverage and degree of additional severe potential will to some degree depend on the evolution of morning convection and any lingering boundaries/cold pool. If forecast instability is realized, a resurgent severe threat would be likely by Thursday afternoon/evening. Amid still-favorable deep layer shear and 6-7 C/km lapse rates, damaging wind gusts and large hail could be expected. A Day 3 Slight Risk thus envelopes most of the area generally along and south of the I-85 corridor to account for this risk. Lastly, models continue to highlight a potential eastward- moving MCS that would track along/north of the Gulf coast late Thursday into Thursday night that could possibly skirt southern portions of the area and perhaps pose an additional severe risk. Thereafter, some PoPs will linger across Middle Georgia on Friday before the front finally clears the area Friday night. Northwest flow aloft will persist through the weekend into early next week while high pressure returns at the surface. A couple of shortwaves could swing across the area within the northwest flow aloft over the weekend, but at this point kept PoPs 10 percent or less. Much more comfortable below normal temperatures and low humidity will persist into early next week. RW && .AVIATION... (12Z TAFS) Issued at 608 AM EDT Tue May 7 2024 Surge of IFR clouds coming in from the SW. It should reach ATL around 12Z. Added a tempo group for bkn010 until around 14Z. Some small potential for 007-007, but not confident enough to make that bkn at this time. Sct afternoon cu is expected with some sct/ocnl bkn cirrus. Pops too low to mention at this time. Winds will remain on the west side. //ATL Confidence...12Z Update... Med confidence cigs. High confidence remaining elements. NListemaa && .PRELIMINARY POINT TEMPS/POPS... Athens 68 89 69 85 / 20 40 30 80 Atlanta 70 88 69 85 / 30 40 40 80 Blairsville 65 81 63 77 / 40 40 80 90 Cartersville 68 87 66 85 / 40 40 60 90 Columbus 70 91 71 89 / 10 20 10 70 Gainesville 69 86 69 83 / 40 40 50 90 Macon 70 91 71 88 / 10 20 10 70 Rome 68 87 67 85 / 50 40 70 90 Peachtree City 68 89 69 86 / 20 30 30 80 Vidalia 70 92 71 92 / 10 10 10 50 && .FFC WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...NListemaa LONG TERM....RW AVIATION...NListemaa