A snowstorm, followed by a few sunny days and then another snow and ice storm – this is a summary of the weather conditions in Georgia since late January.

But a University of Georgia climatologist says don’t be surprised if the polar vortex sends another snowstorm and a late frost before spring officially arrives.

The polar vortex is a large pocket of low pressure and cold, strong, upper-level winds that normally sits over the polar region during the winter season.

“Usually it sits on top of the globe like a hat, but this year it has slid forward over the U.S.,” said Pam Knox, an agricultural climatologist with the UGA College of Agricultural and Environmental Sciences.

Until this week, the atmospheric waves associated with the polar vortex had California “stuck” under high pressure, which kept the state dangerously dry through out the winter “rainy” season. It has also caused Fairbanks, Alaska, to be abnormally warm and Siberia to experience one of the warmest winters in its history, Knox said during an agricultural weather outlook session at the Georgia Organics Conference held last month on Jekyll Island.

“This polar vortex is not something new. It’s been in the literature since 1940,” she said. “Some years we have high swings in temperature conditions and this happens to be one (of those years.)”

This unpredictability could cause havoc for Georgia farmers and gardeners this spring, she added. For instance, if Georgia fruit trees begin to flower and a late frost hits the state, the fate of peach, blueberry and other fruit crops will be threatened.

“That could really decimate the fruit crop this year,” Knox said. “The chances for a late frost are higher this year. In Athens, the flowering plum trees on campus have already come out, and that’s pretty early.”

When warm temperatures fill days in March, home gardeners might be tempted to get outside, dig in the dirt and plant seeds or young transplants. Knox warns gardeners not to give in to the temptation.

“The chance of a late frost is more likely this year, so hold back a bit,” she said. “If not, you may lose that first crop and have to go back and replant everything.”

Source - http://chronicle.augusta.com/