The ridge of high pressure that until recently covered much of the country has split into separate lobes over the South and Northwest.  The Southern piece of the ridge should continue to slowly retreat, with showers and cooler air subtly shifting southward.  However, only limited heat relief will occur across the southern Plains.  Meanwhile, the Northwestern ridge will become a more dominant feature and roll eastward, with heat spreading across the Plains during the weekend.  During the next few days, heavy showers (locally 2 to 4 inches or more) will maintain the flash-flood threat from the Four Corners region eastward to the central Appalachians.  In contrast, little or no rain will fall in the south-central U.S., the Far West, and much of the North.

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