Since returning to Colorado, I have enjoyed a couple of pleasant, autumn days on our Littleton farm but a dose of winter is on its way. As I write this post, gusty northeast winds have developed along the Front Range and bright sunshine has given way to a dense, gray overcast.
Rain is expected to develop by late afternoon, changing to snow during the overnight hours. Since the leading edge of this atmospheric trough is moving rapidly to the south, our upslope flow will be rather brief and only a few inches of snow are expected in Metro Denver. Dipping southward, from the Front Range to the Southern Plains to the Mississippi Valley, this pocket of winter will ignite thunderstorms along its southern and eastern margins, where it will clash with warm, humid air flowing up from the Gulf of Mexico.
As the trough moves off to the east, our winds will shift around from the southwest, bringing afternoon highs near 70 degrees F by the weekend. Gyrations in the jet stream account for these rapid swings in weather; most common in the spring, they occur in autumn as well before a zonal flow allows winter to settle in across Temperate latitudes of North America.
Rain is expected to develop by late afternoon, changing to snow during the overnight hours. Since the leading edge of this atmospheric trough is moving rapidly to the south, our upslope flow will be rather brief and only a few inches of snow are expected in Metro Denver. Dipping southward, from the Front Range to the Southern Plains to the Mississippi Valley, this pocket of winter will ignite thunderstorms along its southern and eastern margins, where it will clash with warm, humid air flowing up from the Gulf of Mexico.
As the trough moves off to the east, our winds will shift around from the southwest, bringing afternoon highs near 70 degrees F by the weekend. Gyrations in the jet stream account for these rapid swings in weather; most common in the spring, they occur in autumn as well before a zonal flow allows winter to settle in across Temperate latitudes of North America.
