317 FXUS62 KFFC 230600 AFDFFC Area Forecast Discussion...Updated for Aviation National Weather Service Peachtree City GA 100 AM EST Wed Dec 23 2020 .UPDATE... Another quiet ridge dominated night on tap as sfc high slides into the mid-Atlantic and just some low level fetch shifting to out of the east. Mostly clear skies and near normal temps expected as all the main focus remains later Wed through Thurs with next strong frontal system. Otherwise little minor adjustments made to overnight temps/dewpts and previous discussion follows... 00z Aviation update below. Baker && .PREV DISCUSSION... /Issued 252 PM EST Tue Dec 22 2020/ SHORT TERM /Tonight through Wednesday Night/... Northwest flow aloft today as ridge moves into the area today through tonight, keeping skies clear. Large surface high will rapidly move over and east of the area today into tomorrow, bringing a shift of winds from the NW today to the E/SE tomorrow. Strong sfc low is progged to develop over the northern plains and move to the NE tomorrow driving a strong cold front at the surface. Strong CAA will allow the trough to dig across the SE US providing broad area of lift out ahead of it in the CVA region. Strong low will also bring a large fetch of moisture from the gulf. Rain chances will begin to increase as a result at the tail end of the short term Wednesday evening into overnight well before the actual front arrives to the area (which will be covered by the long term). Clouds and WAA in the warm sector should keep temps relatively warm overnight, and enough elevated instability may be present to squeeze out some thunder. Lusk && .LONG TERM /Thursday through Tuesday/... The beginning of the long-term forecast period will be active as a strong cold front rapidly pushes into the state. Widespread rainfall will be ongoing at the beginning of the period Thursday morning with the cold front entering northwest Georgia. Healthy rainfall totals continue to be expected as PWs surge into the 1 - 1.5" range, which is at least in the 90th percentile based on sounding climatology for late December. While surface CAPE will be very weak, sufficient elevated instability will allow for a few thunderstorms within this activity ahead of the front. Given weak surface instability, the threat for severe thunderstorms remains low, though very strong wind fields could allow for an isolated gusty wind threat in any of these storms. The focus then turns to the cold air rushing in behind the cold front and any attendant potential for snow. Unfortunately for the snow lovers hoping for a White Christmas, accumulating snow is not expected for most of us. While there will be a narrow window where exiting precipitation could briefly interact with strong cold air advection and change into light snow in north Georgia, this would be fleeting before precip quickly ends and not amount to any accumulations for most areas. The exception will be the mountain counties in far north Georgia where temperatures will more quickly fall below freezing behind the front and a changeover may lead to light accumulations. Additionally, while moisture behind the front will be quite limited, lingering light snow showers will remain possible in the mountains due to interaction of the upper trough, which may lead to additional light accumulations. All told, even in the mountains, total accumulations appear to be on the light side. Highest accumulations of perhaps 1-2" would be relegated along the highest peaks with amounts under an inch in the remainder of the far north counties. Otherwise, Christmas Day will be cold. Highs will struggle to rise above freezing in north Georgia and barely rise above 40 in central Georgia. In fact, if the current forecast high of 35 at Atlanta is realized, it would tie for the 5th coldest Christmas high temperature and the coldest since 1989. Temperatures will gradually moderate through the weekend, approaching normal highs by Sunday. The next weak system looks to approach by Monday or so, though some minor timing differences remain between models. At any rate, QPF appears minor at this time. RW && .AVIATION... 06Z Update... VFR conditions for the remainder of the night and into much of the day with mostly clear skies and some cirrus. Ceilings lowering to MVFR after 03z Thursday with shower chances increasing also. Winds light northeast or variable until around 13z then becoming east 8 to 10 kts. //ATL Confidence...06Z Update... High on all elements. 41 && .PRELIMINARY POINT TEMPS/POPS... Athens 35 60 47 56 / 0 0 60 100 Atlanta 35 59 46 53 / 0 0 70 100 Blairsville 32 51 41 49 / 0 5 90 100 Cartersville 35 60 42 52 / 0 10 90 80 Columbus 38 65 48 56 / 0 0 70 90 Gainesville 36 56 45 53 / 0 0 80 100 Macon 35 65 50 60 / 0 0 40 100 Rome 33 60 43 52 / 0 10 100 70 Peachtree City 35 61 46 54 / 0 0 70 100 Vidalia 39 68 55 68 / 0 0 20 80 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...41 LONG TERM....RW AVIATION...41