Area Forecast Discussion
Issued by NWS Atlanta, GA
Issued by NWS Atlanta, GA
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583 FXUS62 KFFC 211023 AFDFFC Area Forecast Discussion National Weather Service Peachtree City GA 623 AM EDT Tue May 21 2024 ...New 12Z Aviation Discussion... .SHORT TERM... (Today through Wednesday) Issued at 410 AM EDT Tue May 21 2024 High pressure aloft and at the surface through the short term period will produce warm and dry conditions throughout the short term period. The one exception to this will be across northeast Georgia this afternoon and evening where isolated showers and thunderstorms will be possible as a weak disturbance to the north passes. With favorable prevailing surface winds out of the southeast providing a modest enhancement of daytime upslope winds, SBCAPE between 500- 1000+ J/kg, and some moisture remaining in the lower levels of the atmosphere, convection in mountainous terrain will be possible today. Max daily temperatures will climb into the low to mid 80s today with temperatures reaching the mid to upper 80s tomorrow where areas in elevated terrain will remain in the 70s. Overnight lows will range from the upper 50s to mid 60s. KAL && .LONG TERM... (Wednesday night through Monday) Issued at 410 AM EDT Tue May 21 2024 The long term period will begin Wednesday night with upper level ridging over the East Coast and continuing out towards the Atlantic. Meanwhile, an occluded low pressure system will be in centered in southeast Canada and drifting slowly to the north. Between these two features, southwesterly upper flow will set up over much of the eastern CONUS, including north Georgia, leading to increasing atmospheric moisture. A cold front extending from the low will have moved into the Tennessee Valley region as the period begins, at which point it will gradually sink southward towards north Georgia over the course of the day. After the morning starts out with lows in the mid to upper 60s, isolated to scattered showers and thunderstorms will begin to advance into far north Georgia by early Thursday morning as a weak disturbance traverses the upper-level flow and overruns the frontal boundary. PoPs on Thursday and Thursday night will mostly be confined to north of the I-20 corridor, with low-end chance PoPs in the far northern tier and and progressively lower chances to the south. Diurnal instability will be sufficient for the development of thunderstorms on Thursday, although severe weather is not likely at this time. Even in spite of increased cloud cover across far north Georgia near the front, the warming trend from the short term period will persist, with highs forecast to be in the upper 80s in north Georgia and low 90s in central Georgia. These high temperatures will be consistent with what can be expected for the remainder of the week and into the weekend, which will run about 5-9 degrees above climatological normals areawide. As the low continues weakens and moves away to the northeast, the upper flow will become more zonally oriented and the frontal boundary will become more elongated from west to east, with its southward advance will slowing significantly. By Friday morning, the frontal boundary is forecast to stall near the Georgia/Tennessee state line. A more robust shortwave will traverse the westerlies and from the Lower Mississippi River Valley across the Southeast on Friday into Friday night. This setup is likely to bring more numerous showers and thunderstorms to the forecast area on Friday, especially where the wave overruns the stalled frontal boundary, providing a focus for additional convection. Uncertainty still remains in the model guidance with respect to the strength and exact position of this disturbance, which will influence where the most widespread precipitation will occur. While the frontal boundary will begin to dissipate by early Saturday morning, additional disturbances will continue to traverse the zonal westerlies and move through the Southeast this weekend. Scattered showers and thunderstorms are thus expected on both Saturday and Sunday, with the highest chances during the afternoon each day where diurnal instability will be greatest. King && .AVIATION... (12Z TAFS) Issued at 604 AM EDT Tue May 21 2024 VFR conditions through TAF cycle. SCT/BKN060 will become FEW050 through the day as the cumulus field develops. ESE winds today will be at 5KT or less. Overnight, SKC/FEW250 with winds become light and variable. Winds will shift to the SW after 12Z tomorrow at KATL and a SCT cumulus field with cigs at 040 returns mid morning tomorrow. //ATL Confidence...12Z Update... High confidence on all elements. KAL && .PRELIMINARY POINT TEMPS/POPS... Athens 61 88 64 89 / 0 0 0 10 Atlanta 65 88 68 89 / 0 0 0 10 Blairsville 59 82 61 82 / 0 0 0 30 Cartersville 63 88 66 89 / 0 0 0 10 Columbus 64 88 67 90 / 0 0 0 0 Gainesville 64 86 66 87 / 0 0 0 20 Macon 62 88 66 90 / 0 0 0 0 Rome 64 88 66 89 / 0 0 0 10 Peachtree City 61 88 66 89 / 0 0 0 0 Vidalia 63 88 67 91 / 0 0 0 0 && .FFC WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...KAL LONG TERM....King AVIATION...KAL