Area Forecast Discussion
Issued by NWS Atlanta, GA
Issued by NWS Atlanta, GA
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661 FXUS62 KFFC 181749 AFDFFC Area Forecast Discussion National Weather Service Peachtree City GA 149 PM EDT Tue Jun 18 2024 ...New 18Z Aviation Discussion... .SHORT TERM... (Today through Wednesday) Issued at 258 AM EDT Tue Jun 18 2024 Highlights: -Warm temperatures continue through the Short Term. -An isolated shower cannot be ruled out over in NE GA and across south-central GA This afternoon and again Wed afternoon. Current satellite loop shows mainly fair weather CU developing across North and Central GA. Surface Bermuda ridge and Mid level Mid Atlantic ridge combining to keep things mostly dry over the area but we are in easterly Atlantic flow. Most locations will remain dry through Tonight but some isolated showers and/or storms cannot be ruled out with the easterly flow especially at the highest elevations in the northeast (terrain induced) and across far south-central Georgia. Any storms that develop could produce gusty winds and locally heavy rainfall. Temperatures are still forecast to be slightly `cooler` than previous days with forecast highs in the upper 80s to low 90s (80s in the mountains). Forecast lows will be in the upper 60s to low 70s. Lower dewpoints and afternoon RH values will keep heat indices near the actual temperature. Nevertheless, continue to be proactive if outdoors! 07 && .LONG TERM... (Wednesday night through Monday) Issued at 258 AM EDT Tue Jun 18 2024 Key Messages: - A gradual rise in temperatures is expected between Thursday and Monday, with heat index values between 100 and 105 degrees possible by early next week. - Generally dry weather is forecast through Saturday, then thunderstorm activity may pick up in the region during the first half of next week. Thursday: No tangible changes have been made to the forecast for Thursday. Guidance still favors a strong (598 dm at 500 mb) ridge over the Mid- Atlantic. Though recent model runs have sought to extend the core of the ridge further to the west (through the central Appalachians and into TN & KY). Across Georgia this shift in the ridge suggests a greater eastelry component to our winds aloft, but it doesn`t portend any significant changes to the temperature or precipitation forecast. Low PW values and limited instability should still result in dry weather across central and northern Georgia, and high temperatures in the 88 to 93 degree range are anticipated. Pattern shifts between Friday and Early Next Week: Trends in the GEFS and EPS guidance continue to favor a weakening trend and westward shift in upper level ridge during this period as a trough moves through the Great Lakes and eastern Canada. This may bring some gradual cooling to the Northeast, though it will have minimal impacts for the Southeast. Our temperatures in Georgia may actually rise due to projected increases in temperatures in the lower half of the atmosphere (850 mb temps rising to 2-4 C above average). Our forecast highs from Friday through Tuesday remain close to the NBM mean, suggesting highs in the upper 90s for most of the region over the weekend. Some areas could see highs break the tipple digit barrier. NBM guidance gives Atlanta a 14% chance to reach 100 degrees on Sunday, while Macon has a 27% chance of reaching the same threshold. For now the forecast keeps the regions heat index values below 105 degrees (the threshold for a Heat Advisory). A small change of only 1-3 degrees in the forecast dewpoints or temperatures could push heat indices above 105 (especially on Sunday or Monday), and thus there is a non zero chance of a Heat Advisory for portions of the state this weekend or early next week. Another feature to watch over the weekend will be an easterly wave tracking through the Western Atlantic (near the Bahamas). The National Hurricane Center has maintained a 20% chance (a slight downward shift from 30%) for this feature to develop into a tropical system with their latest outlook. Though this is a slight decrease, it doesn`t change the overall message, and this is still a feature that that will need to be monitored for potential impacts in Georgia. A look at the ensemble guidance does suggest one interesting forecast trend with this feature over the last 24 hours. In general, the GEFS and EPS members have shifted towards a slower and more eastelry track, which slightly slows the return of higher PW values to Georgia. Both ensembles means are 12-24 hours slower with PW values reaching 1.5 inches across the state. This shift appears to be largely due to slightly stronger ridging to our west impeding the westward progress of the eastelry wave. From a forecast stand point it suggests a slight delay in the return of scattered shower and thunderstorms chances to the state. Thus our forecast rain chances have fallen below 15% for most of north Georgia on Saturday, though 15-30% chances remain for Central Georgia. All things considered tough, forecast confidence remains high that we will shift towards a pattern more favorable for isolated to scattered thunderstorms early next week. Albright && .AVIATION... (18Z TAFS) Issued at 105 PM EDT Tue Jun 18 2024 VFR ceilings with no precipitation or restrictions to VSBYs expected. Winds will stay out of the East with speeds fluctuations throughout the day. Wind speeds will start in the 10-15kt range with gust to 22kt. Will see these speeds diminish top 10kt 8kt or less after sunset then pick back up again after 15z Wed. //ATL Confidence...18Z Update... Confidence high on all elements 01 && .PRELIMINARY POINT TEMPS/POPS... Athens 67 87 67 89 / 0 0 0 0 Atlanta 71 89 70 90 / 0 0 0 0 Blairsville 63 82 62 85 / 0 0 0 0 Cartersville 70 89 68 91 / 0 0 0 0 Columbus 73 90 70 92 / 0 0 0 0 Gainesville 68 86 68 87 / 0 0 0 0 Macon 69 90 68 91 / 0 0 0 0 Rome 71 89 69 92 / 0 0 0 0 Peachtree City 69 89 68 91 / 0 0 0 0 Vidalia 71 90 69 91 / 10 20 10 10 && .FFC WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...07 LONG TERM....Albright AVIATION...01