An intense dome of heat grips the Central and Southern Plains; yesterday's afternoon highs exceeded 100 degrees F. As Pacific systems approach from the west, they are shunted northward by this dome and move eastward and then southeastward along its rim.
The rim itself is a clash zone, where hot and cool air masses collide, producing bands of thunderstorms that "train" across the same areas. As a result, repeated bouts of torrential rain lead to flash flooding, which was especially severe near Sioux Falls, South Dakota, yesterday.
Until the atmospheric ridge breaks down or shifts from its current location, this weather pattern will persist, enhancing drought across the Southern Plains while dumping a tremendous amount of precipitation into the Missouri and Mississippi River watersheds.
