Area Forecast Discussion
Issued by NWS Atlanta, GA
Issued by NWS Atlanta, GA
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101 FXUS62 KFFC 191044 AFDFFC Area Forecast Discussion National Weather Service Peachtree City GA 644 AM EDT Fri Jul 19 2024 ...New 12Z Aviation Discussion... .SHORT TERM... (Today through Saturday) Issued at 333 AM EDT Fri Jul 19 2024 Thanks to a broad 500 mb trough over the eastern CONUS, and a stationary boundary that has stalled over north Georgia, the short term forecast is going to sound a bit like a broken record with similar conditions on the horizon as to what we have seen over the last several days. As the surface boundary remains in place and a shortwave approaches from the west, southwest winds will advect abundant moisture from the Gulf of Mexico into the atmospheric column. As disturbances within the upper level flow pass overhead, multiple waves of shower and thunderstorm activity are expected to occur today, into the overnight hours, and again on Saturday. The bulk of the thunderstorm activity is expected to be driven diurnally, and is most likely to occur primarily during the afternoon and early evening hours. However, a few rumbles of thunder outside of this timeframe will certainly be possible. With SBCAPE peaking between 1000-2000 J/kg during the afternoon and bulk shear ~25kt, a few storms could become strong, but the probability for widespread severe weather remains low. With PWATs north of 2.0", a few strong storms could produce instances of locally heavy rainfall. While this forecast isn`t particularly conducive to spending time outdoors this weekend, at least cooler daytime temperatures will prevail, with locations north of a line from Columbus to Eatonton to Washington in the 80s with areas south in the low 90s. KAB && .LONG TERM... (Saturday night through Thursday) Issued at 333 AM EDT Fri Jul 19 2024 Key Messages: - Numerous afternoon and evening thunderstorms will continue in the region over the next 7 days. - Slightly below average high temperatures (by 2-5 degrees) and above average rainfall are favored in northern and central Georgia through next Thursday. A Rinse & Repeat Forecast Next Week: As we move through the upcoming workweek the ensemble guidance (GEFS and EPS) favors a stagnant pattern with upper level troughing over the Central Plains/Midwest and an upper level ridge over the Western Atlantic. Prevailing southwesterly flow between these two features should keep subtropical moisture flowing into Georgia from the Gulf. Mean forecast PW values from the GEFS and EPS remain at or above the 90th percentile (~1.8 inches) through at least next Thursday. The elevated moisture levels should be accompanied by a lack of significant mid/upper level subsidence (thanks to the positioning of the upper level ridge and trough) and this should promote convection. This should be especially true during the afternoon and evening hours each day when diurnal heating is maximized. Run to run trends in the GEFS and EPS guidance have consistently shown 7 day precipitation anomalies (ending next Thursday) of 1 to 3 inches over northern and central Georgia. As such forecaster confidence in above average precipitation through next Thursday is moderate (especially over northern Georgia). Though thunderstorms are anticipated each day, severe weather remains unlikely through next Thursday due to a lack of appreciable wind shear. A few strong storms could still occur each day, with precipitation loading supporting isolated downburst wind gusts near 40 mph. Lower heights induced by the trough to our west and cloud cover from diurnally driven convection should keep our high temperatures at or below seasonal averages during the upcoming work week. Our running forecast keeps afternoon highs in the upper 80s for most of northern Georgia with low 90s in central Georgia. If these readings materialize, they would be 2 to 5 degrees below seasonal averages for the second half of July (the largest deviation in northern Georgia). Albright && .AVIATION... (12Z TAFS) Issued at 634 AM EDT Fri Jul 19 2024 Mixed bag of VFR/MVFR/IFR cigs this morning. Could see a few locations across the metro with IFR cigs intermittently through 13Z. Ceilings will generally trends towards high end MVFR/VFR through the morning and afternoon. Rounds of -SHRA begin generally around 15Z for MCN/CSG and 18-19Z for northern locations with TSRA from 18-23Z. -SHRA expected to linger through overnight and into the morning hours. TSRA returns to KATL after 16Z Saturday. //ATL Confidence...12Z Update... Medium confidence on TSRA timing and IFR cig coverage this morning. High confidence on remaining elements. KAB && .PRELIMINARY POINT TEMPS/POPS... Athens 70 87 70 89 / 70 80 70 80 Atlanta 70 85 71 86 / 70 80 70 80 Blairsville 65 80 65 80 / 70 80 70 90 Cartersville 69 85 69 85 / 70 80 70 90 Columbus 72 90 72 91 / 60 80 60 80 Gainesville 70 84 71 85 / 70 80 70 80 Macon 70 91 71 91 / 50 70 60 80 Rome 70 85 70 85 / 60 80 70 90 Peachtree City 69 87 70 87 / 70 80 70 80 Vidalia 73 93 74 94 / 50 70 40 70 && .FFC WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...KAB LONG TERM....Albright AVIATION...KAB