What Causes an Arctic Outbreak?

Morning Lows, Image: NOAA

Another surge of arctic air is spreading across the US. Temperatures have dropped below zero is as many as 12 states today. These large pools of arctic air produce dangerous conditions for the entire country, especially the Upper Midwest. In the Southern States, the “arctic chilled” air can kill sensitive crops that depend on the warmer climate during the wintertime. The cold air also just stresses our minds, bodies, and heating resources at this time of year!

So what causes these arctic outbreaks? The easy answer is the Arctic Circle, or the North Pole, gets very little sunlight at this time of year. Not only is there very little sunshine to warm the air, the little bit of sun the Arctic gets is reflected away from the landmasses by snow and ice. Short days and long nights make for a VERY COLD WINTER.  The long nights can allow temperatures to drop to -40 degrees at the top of the earth!

Arctic Outbreak Explainer, Image: NOAA

So, all winter long, cold air is building in the Arctic Circle. But what finally causes this air to move, to take the plunge south, and bring the “arctic chilled” air to the Central and Southern US?

According to Keith Heidorn from The Weather Doctor,

“…    Eventually high-altitude winds catch the air masses and push them outward, usually toward the south and east as huge High pressure systems… Each winter much of central and eastern North America typically receives several great blasts of cold arctic air. They chill us to the bone and often produce ground blizzard and extreme wind chill conditions in addition to the frigidly cold temperatures.”

Yesterday, the cold blast came when an arctic cold front swept across the middle of the country. Temperatures were falling to the teens, then single digits, then below zero in places like Kansas City, Missouri, Lincoln, Nebraska, Des Moines, Iowa, and Butte, Montana.

The temperature dropped 10 degrees in one hour in New Orleans, Louisiana yesterday! After hitting a high of 60, they are now looking at a morning low in the upper 20s.

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-Dawn Brown