Friday, August 21, 2009

A Benevolent Front

Having pushed through Columbia during the early morning hours of August 20, bringing strong winds, intense lightening and heavy rain, the latest cold front has pushed on to the south and east. In its wake, cooler, drier air has spread across the Midwest and will continue to expand for the next few days, providing an early taste of autumn and a welcome reprieve from the heat and humidity of recent weeks.

While bringing glorious weather to the Midwest, this potent front is also responsible for steering Hurricane Bill to the north, keeping its dangerous winds off the East Coast. As the trough continues to broaden and push eastward, the path of the storm will actually curve back to the northeast, posing problems for the Canadian Maritimes but sparing the U.S.

Weather events are governed primarily by shifts in the jet stream and timing is crucial when it comes to the trajectory of hurricanes. Had the front stalled in the Midwest, Bill might have slammed into Florida or the Carolinas, causing massive destruction. As it turns out, the cold front, produced by a dip in the jet stream, kept the storm at sea.