Actually, I think that would be reasonable map because it is on an almost perfect radiational cooling night with a surface high overhead/calm winds/dry air/clear skies, when heat islands make the biggest difference for lows. In contrast, south GA rural locations and even SAV(a well inland airport) often radiate better during these kind of nights and allow them to have lows colder than downtown Atlanta and certainly ATL airport (KATL). They have SAV at 31, while they have downtown near 33...that's very believable. Where I don't think is cold enough is the radiational cooling capital of the ATL area, Peachtree City (KFFC), which they have only going down to 29 with a dewpoint in the teens. I'd expect them to get to near 25 and be near the coldest in GA. But that's way too microscale for the GFS. Another constant microscale related error: ATL airport (KATL), which is often the warmest in the state. They have KATL getting down to 29, which is the same as KFFC and KPDK ( in NE ATL burbs), because the heat island bubble being shown is just to their north in town. There's no way that relationship would verify. I could see KATL being, say, 34, KPDK being, say, 29, and KFFC being, say, 25 (and KSAV at 31).
