Like the smoke from a funeral pyre, a plume of moisture has spread across the Heartland over the past two days. Its origin was in the mountains of northern Mexico, where Hurricane Alex met her fate. The copious moisture that the storm pulled in from the Gulf of Mexico has since been drawn into the Southern Plains and Midwest as a cold front approaches from the west.
The relatively dry, mild air of last week has given way to hazy skies and the increasing humidity is priming our region for showers and thunderstorms. The trigger will be the cold front, attached to a Pacific storm that has crossed the Central Rockies. Still a bit west of our location, the front will lift the remnants of Alex, producing a wide swath of precipitation that will dominate our weather through the coming week.
This scenario is typical of summer weather patterns across the Midwest. While the hurricane injected an unusually large amount of moisture into Texas, the Gulf of Mexico is always the primary source of precipitation for most of the Central and Eastern U.S. Though the storm systems arrive from the west, their Pacific moisture is wrung out by the western mountains and it is their ability to tap Gulf moisture that determines the location and intensity of rainfall across the Plains and Midwest.
