On its annual push to the south, the jet stream has settled down across the northern States this week, guiding a series of Pacific storms across the country. Acting as a barrier, this steering current is also keeping the frigid, Arctic air to the north of its flow.
Here in Missouri, buffered from extreme cold, we are experiencing the ups and downs of each frontal passage. Ahead of the storms, southerly winds bring mild conditions, with highs in the fifties; behind the fronts, the wind shifts to the northwest, dropping overnight lows into the 20s and afternoon highs into the upper 30s. Since the storm centers are well to our north, most of the rain and snow will occur across the northern Rockies, the Dakotas and the Great Lake States, including lake-effect snows east of the Lakes.
Such roller coaster patterns are typical of early spring and late autumn, when the jet stream is caught between summer and winter. For now, we'll enjoy the brief, dying gasps of autumn, but our descent into the cold, dark season has begun.
