Area Forecast Discussion
Issued by NWS Atlanta, GA
Issued by NWS Atlanta, GA
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573 FXUS62 KFFC 121854 AFDFFC Area Forecast Discussion National Weather Service Peachtree City GA 254 PM EDT Sun May 12 2024 ...Afternoon Area Forecast Discussion... .SHORT TERM... (This afternoon through Monday) Issued at 248 PM EDT Sun May 12 2024 At a glance: - Increasing cloudiness tonight, with rain spreading NE into the area late tonight and Monday morning. - Locally heavy rainfall possible across the S by late Monday. Thick high clouds have shifted S to near and S of CSG and MCN. Otherwise, skies are mostly sunny to partly cloudy with thinner high clouds. Early afternoon temperatures ranged from the mid 60s over the NE mountains to the mid 70s over the SE. A weak upper ridge will build over the area tonight ahead of an approaching upper low. This low will move from the Central Plains to the central MS Valley by late Monday night. At the surface, low pressure will lift NE into the mid-MS Valley. A warm front will begin to lift NE from the Gulf Coast with fairly robust isentropic lift spreading across the area from the SW and W. This will promote lowering and thickening clouds tonight, with rain spreading into the area late tonight and early Monday morning. The heaviest rainfall rates are expected to set up closer to the warm front over the S portion of the area, with 1 to 2 inches of rainfall likely near the Columbus area by daybreak Tue. Most of the activity will start off as showers, with scattered thunderstorms possible over the SW half of the area by late Monday afternoon and Monday evening. Low temperatures tonight will drop into the lower 50s across the NE mountains, ranging to near 60 in the Atlanta metro area and lower 60s across the S. Due to the thickening cloud cover and rain, highs on Monday will range from the mid 60s across the NE mountains to the upper 70s across the extreme S. As rainfall continues Monday night, overnight lows will only drop into the lower to mid 60s in most locations, with some upper 50s in the NE mountains. /SEC && .LONG TERM... (Tuesday morning through next Saturday) Issued at 248 PM EDT Sun May 12 2024 At a glance: - Bookend chances for showers and thunderstorms - Temperatures slightly below average To kick off the extended range on Tuesday, a closed mid-level low will be making its way across the Midwest. Mass response leads to the formation of an accompanying surface low,and the combination of the two will serve as the impetus for our first wave of rain (and storm) chances. Much of the forecast -- especially as it pertains to chances for severe weather -- will hinge on how far north the warm front drifts during the day Tuesday. Kinematics (30-40kt jet at 850mb) support the development of isolated strong to marginally severe storms during the afternoon and evening, but should the frontal push be further south than currently analyzed, the most unstable airmass would be relegated to just portions of our far southern tier. On the opposite side of the coin, a stalled front across south central Georgia would serve as a source for continued re-development of storms and an increased risk for flash flooding. Sandier soils south of the Fall Line do require more precipitation before becoming saturated, and current 36 hour rainfall totals are between 2-3" (with locally higher amounts as high as 4"). With all that said, SPC currently has the entire state under a Marginal (1/5) Risk for severe weather, and WPC has outlined a Slight (2/4) Risk for excessive rainfall south of the I-85/I-20 interchange. Better detail will be available in coming model runs. We`ll see clearing from south to north moving into Wednesday as mid- level forcing exits and continues to sweep across the DelMarVa region. Wraparound precipitation in the wake of the surface low is in the cards for areas north of I-20 on Wednesday, but coverage will be light and patchy, and additional QPF is expected to be low (<0.25"). A shortwave, low amplitude ridge moves in across the Ohio and Tennessee River Valleys in the wake of Tuesday`s weather, and more tranquil conditions are expected through Friday morning. Beyond that, chances for showers and thunderstorms look to return once again to close off the work week with the arrival of yet another frontal system, but disagreement among global models precludes giving much more detail than that. Highs each day will be heavily dependent on cloud cover and precipitation chances (or lack thereof). Tuesday, Wednesday, and Friday -- the rainiest of the long term -- look to see highs top out in the lower-70s to lower-80s (and mid 80s for far south central Georgia). Otherwise, highs in the 80s. Lows will be fairly uniformly in the upper-50s to 60s. 96 && .AVIATION... (18Z TAFS) Issued at 150 PM EDT Sun May 12 2024 VFR conditions will continue through the evening, with gradually deteriorating conditions from the W after midnight tonight. Showers will spread into CSG by daybreak, with rain spreading across the remainder of the terminals through Mon morning. Have opted for lower ceilings (IFR) in rain as model soundings look to be nearly saturated in the lower levels at the expected onset of precipitation. Rainfall is not expected to be too heavy through the end of the forecast period other than at CSG. However, due to the expected moisture levels in the boundary layer, vsbys may be further limited by fog. Winds will be very light, although SE winds will begin to increase at the end of the period. //ATL Confidence...18Z Update... Medium for timing of rain onset along with cig heights and vsbys in rain, high for other elements. SEC && .PRELIMINARY POINT TEMPS/POPS... Athens 56 71 61 75 / 0 70 100 100 Atlanta 60 69 62 77 / 30 80 90 100 Blairsville 52 67 57 69 / 0 60 90 100 Cartersville 57 71 61 77 / 30 80 90 90 Columbus 63 75 65 80 / 40 90 90 100 Gainesville 58 69 62 73 / 0 70 90 100 Macon 61 74 64 79 / 20 90 90 100 Rome 57 72 62 77 / 30 80 90 100 Peachtree City 59 70 62 78 / 40 90 90 100 Vidalia 64 77 65 81 / 10 70 90 100 && .FFC WATCHES/WARNINGS/ADVISORIES...None. $$ SHORT TERM...SEC LONG TERM....96 AVIATION...SEC