As if our political polarization was not bad enough, the jet stream has now divided our country. This afternoon, a broad dip in the jet has brought winter conditions to the western U.S. while the eastern half, protected by a dome of high pressure, basks in summertime warmth. The dividing line between the trough and ridge runs north to south across the Central Plains; on either side of this cold front the temperature varies by 20 degrees F.
Such potent contrasts set the stage for severe weather and, once the trough moves into areas primed with Gulf moisture, thunderstorms will ignite. Meanwhile, within the trough, an upper level low is spinning from the northwest to the southeast, producing mountain snows and bringing the first significant upslope snow to Front Range cities.
Over the next few days, the protective dome will shift eastward, summer will retreat and a taste of winter will invade the Heartland. Here in Missouri, we'll escape the western snow but chilly rain and blustery weather will deliver a reality check; it is, after all, November.
