We have definitely seen bouncy weather in the Gainesville area. In 2019, the average temperature reported by the National Weather Service (NWS) on weather.gov was 5 degrees above normal. About 4 inches of rain was missing from Hall County’s 42-inch annual average. So far this year, thanks to Delta and other tropical systems that passed through here, we have received 20 inches above normal, with 10 weeks still to go for 2020. It wasn’t as hot as last year, but the average temperature so far has been 3 degrees above normal.
The trend of bouncy weather, swinging in both directions on the temperature and precipitation scale, is likely to continue. It’s nature’s reaction to the net overall warming of the globe. The NWS predicts normal rainfall in Georgia for the rest of the year, along with slightly higher temperatures.
What these outlooks can’t predict is the variability of weather from one week to the next. But based on traditional Georgia weather of the past, we know what’s coming. Following the traditionally quiet, sunny days of October, November will be bringing frontal systems in earnest. They start with a warm front, in most cases. The weather changes from balmy and clear to warm and humid. That’s because the warm front is the edge of an air mass arriving from the Gulf of Mexico. Last week, sea water temperature near its center, and at Florida’s western coast, was still in the mid-80’s. A couple of days after the warm front that’s likely to bring us some unseasonably warm weather, the cold front arrives. It’s part of the same frontal system. The cold front is the edge of a mass of air coming to us from places like the Canadian Yukon Province, northern Saskatchewan and others. That far north, daytime highs are only in the 30’s, and at night the mercury drops below freezing. Because the differences in temperatures and moisture are increasing across the continent, we can expect stronger activity from these frontal systems.
In late fall and winter, they tend to follow one another like freight trains on a track. Among those systems with their warm-cold punch, some are likely to get severe in places. If there are two frontal systems following each other closely, and their chilly northwestern portions are cold enough, we might even see snow before 2020 ends.
Rudi Kiefer, Ph.D., is a professor at Brenau University, teaching physical and health sciences on Brenau’s Georgia campuses and in China. His column appears Sundays and at gainesvilletimes.com.