After getting shoved to the Gulf Coast by a series of cold fronts, summer has returned in the form of a broad atmospheric ridge that covers the eastern half of the U.S. Beneath this dome of high pressure, winds are light, air is sinking, cloud formation is suppressed and the early autumn sun bakes the landscape. Since the ridge also cuts off flow from the Gulf and the Atlantic, humidity within the dome is low, the warm days are comfortable and radiation cooling develops at night, allowing temperatures to fall into the forties and fifties (F).
Here in Missouri, we will top out in the low to mid eighties over the next few days and, though the foliage hints of autumn, it will feel more like summer. While we humans may be temporarily fooled by the atmospheric conditions, wildlife, responding to the waning daylight, will carry on with their preparations for winter, storing food or winging off to southern lands.
Summer has won this battle in its perpetual war with winter but the victory will be short lived. A trough in the West is bringing cool rains and mountains snows to the Four Corners region and, as the ridge of summer shifts to the east, conditions across the Heartland will become more seasonable. Time is on winter's side; the nights will continue to lengthen, the temperatures will fall and summer will be banished to the Southern Hemisphere.
