The other day I blogged about the Florida snowstorm of 1977. Could it happen again? Absolutely, but a combination of factors would have to come together just like they did three decades ago.
1977 turned out to be the coldest Winter on record East of the Mississippi. 24 cities posted their coldest January in history. But why? The chart above is the surface analysis for the coldest week of 1977. Arctic air flooded into the Deep South the entire Winter, due in part to the Aleutian Low, a semi permanent weather maker that was unusually strong and developed early in the Winter. For several months, very cold dry air raced south across the country. There was never a break in the bitter temperatures for months. Two days before the snow outbreak, a Nor'easter formed off Cape Hatteras, and this was the final ingredient needed to push the very cold air south of 27N. The cold surge travelled over the Gulf Stream several miles off the Florida Coast, where it picked up enough moisture to form snow flakes. Although Miami stayed above freezing most of the time, the freezing level lowered to 1000', so the flakes didn't have time to melt before reaching the ground.
It will snow again in South Florida. In 2003 snow was observed as far south as Vero Beach, and I saw a few snow flakes in northern Palm Beach County. But it didn't last long, and was not officially recorded at the West Palm Airport.