Yesterday dawned with sunny, mild conditions in Columbia. A gentle breeze from the south had pushed the temperature into the low 50s and there was no sign of coming change in the sky or on the radar. Then, about 11 AM, the winds shifted to the north and grew in strength throughout the day, dropping the temperature ten degrees by late afternoon. Our first freeze of the season occured overnight and we awoke to a clear sky and 31 degrees this morning.
The polar front that dropped through Missouri yesterday morning has moved on to the east and south, bringing the first taste of winter to the eastern U.S. While a lack of moisture prevented the development of showers (or even clouds) with the frontal passage in Missouri, the northwest winds and cold air produced lake-effect snows in the Upper Midwest and Northeast. And in the Southeast, where the humidity was higher, the front brought much-needed rains and thunderstorms in Tennessee and Mississippi.
Still early in the season, this polar outbreak will soon be replaced by a surge of warm air from the southwest. Eventually, as the Arctic cold deepens and solar heating diminishes, the jet stream will retreat to the south and these polar outbreaks will become more frequent, more intense and longer lasting. Winter will then grip the Heartland.
