930 FXUS62 KFFC 050004 AFDFFC Area Forecast Discussion National Weather Service Peachtree City GA 804 PM EDT Sun Apr 4 2021 ...00Z Aviation Area Forecast Discussion with Small Update... .UPDATE... Minor update to hourly temps as they are hanging on to the afternoon warmth a bit longer than forecast. Otherwise, no frost/freeze concerns tonight as low temps should stay in the 40s. Another beautiful day on tap tomorrow. Lusk && .PREV DISCUSSION... /Issued 250 PM EDT Sun Apr 4 2021/ ..Sunday Afternoon Forecast Discussion... SHORT TERM /Tonight through Monday Night/... High pressure regime continues, need we really say more? Afternoon temperatures continue to increase with each day with low 70s today giving way to highs in the mid to upper 70s tomorrow. Overnight, radiational cooling will once again be strong with clear skies and calm winds but should stay in the low 40s, which mean no more frost or freeze threat. The trickiest part of the forecast continues to be the afternoon dewpoints and relative humidities as guidance continues to struggle with deep atmospheric mixing entraining very dry low-level air into the mixing layer, and eventually reaching the ground. A spread of 10-18 degrees exists between the 12Z runs of the HRRR and the NAM3km, with the NBM and other blends splitting the difference. But day after day, we've seen models like the HRRR and ARW perform well under blue sky conditions and so have lowered dewpoints to match resulting in RHs tomorrow afternoon between 20-30 percent. Thiem LONG TERM /Tuesday through Sunday/... Dry conditions will be ongoing to start the forecast period on Tuesday. The center of surface high pressure will be pushing farther off the Florida Atlantic coastline, bringing a return to southerly flow with continued warming temperatures and gradually increasing moisture levels. By Wednesday, a closed upper low will be dropping southeastward through the Central Plains while shortwave ridging will build over the forecast area ahead of it. At the surface, the associated surface low will be occluding over the Plains with the cold front making gradual eastward progress into the Mid South. Wednesday should remain mostly dry locally with temperatures warming near or above 80 degrees across most of the area. While the cold front's forward progress slows to our west, rain chances will increase appreciably by Wednesday night into Thursday as shortwave energy swings eastward. Instability will be limited as convection approaches Wednesday night into Thursday morning, so intensity may be on a downswing at that time. This activity will push eastward across the area through the day Thursday. By Thursday night into Friday, the forecast begins to become less certain. Additional convection may develop to our west near the surface front in association with another shortwave. At this point, chance PoPs were maintained into Friday given uncertainties on finer details. Forecast uncertainty increases further by the end of the period with general consensus that the upper low will remain lingering in the Great Lakes region but less agreement on frontal placement and subsequent shortwave energy. Therefore, chance PoPs remain the rule on Day 7. RW AVIATION... 18Z Update... VFR under SKC will prevail through the period. Winds are light and generally westerly between 4-10kts, but have some variability and very isolated gusts at different sites around the area. Winds should go mostly calm tonight, and be light out of the WSW, below 7 kts, tomorrow in the late morning and afternoon. //ATL Confidence...18Z Update... High on all elements. Thiem && .AVIATION... 00Z Update... VFR conditions continue through the TAF period with SKC. Winds will go variable to calm at most sites tonight. West winds again tomorrow from 4-8 kts, with some slightly higher gusts possible, but not expected to pick up until 16-17Z. //ATL Confidence...00Z Update... High confidence all elements. Lusk && .PRELIMINARY POINT TEMPS/POPS... Athens 43 76 49 79 / 0 0 0 0 Atlanta 45 75 50 76 / 0 0 0 0 Blairsville 40 71 45 73 / 0 0 0 0 Cartersville 40 75 46 77 / 0 0 0 0 Columbus 43 76 48 79 / 0 0 0 0 Gainesville 44 74 50 76 / 0 0 0 0 Macon 41 77 46 81 / 0 0 0 0 Rome 40 75 47 78 / 0 0 0 0 Peachtree City 40 75 46 78 / 0 0 0 0 Vidalia 43 78 50 81 / 0 0 0 0 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Thiem LONG TERM....RW AVIATION...Lusk