A northward shift of the jet stream has allowed a ridge of summer heat to invade the central and eastern U.S. over the past 24 hours and is expected to remain in place for Memorial Day. Blocking the invasion of Pacific fronts, this dome of high pressure is shunting storms along its outer rim and, at least for the Holiday weekend, the soggy and storm-ravaged Midwest will be spared another round of severe weather.
Ushering in the first major wave of summer, this atmospheric ridge should help to dry out the muddy fields that stretch across the till plains and, for now, will reduce flow into our swollen rivers and streams. As expected, the heat has energized the periodical cicadas here in Missouri and the sunny weather, arriving just in time for the traditional kickoff to summer, is especially welcome after a cool, rainy spring.
Of course, this respite will be brief. A deep trough across the West, bringing snow as far south as northern Arizona, will nudge eastward as the ridge begins to collapse; in concert, the storm-laden clash zone will also shift to the east and, fueled by the summer heat, severe weather will erupt across the Heartland. It will be July before the jet stream settles across Canada; until then, its gyrations will plague the lower 48 and destructive storms will continue to grab the headlines.
