Sitting in my office this afternoon, I am looking out at a wall of dark clouds, pushing in from the west. Studded with thunderstorms, this front is the edge of autumn, promising a night of rain followed by the first glorious day of fall-like weather. Our overnight low is expected to dip near 50 degrees F and tomorrow's sunshine will only produce an afternoon high in the mid seventies; both of those extremes will be twenty degrees cooler than what we have averaged over the past few months.
Nearly upon us, the dark clouds look menacing but their trigger, a cool, dry Canadian air mass, is dropping south behind them. Assuming we avoid damaging winds and destructive hail, the heavy rains along the front will be more than welcome and the autumn air that plunges in their wake will provide the first convincing evidence of seasonal change.
No doubt, summer will battle back in the coming weeks but this sudden strike by old man winter is a powerful blow from the north, a welcome invasion across the parched landscape of America's Heartland. Darkness is now gathering at mid afternoon, lightening is flashing across the western horizon, shelf clouds are racing above Columbia and autumn's violent debut is at hand.
