Drought: Rains Bypass the West and Plains

May 10, 2013 by   - () Comments Off on Drought: Rains Bypass the West and Plains

Weather Summary: Due to blocking high pressure over the northwestern Atlantic Ocean, a weather system in the nation’s mid-section stalled and temporarily retrograded westward, dropping widespread moderate to heavy rains on the Mississippi and Tennessee Valleys, Southeast, and Florida. With the addition of a deep southward push of sub-freezing air into the central U.S., accumulating record-late May snows fell as far south as northwestern Arkansas and northeastern Oklahoma.

Unfortunately, the moisture bypassed much of the West and southern Plains, and was blocked by the strong high pressure from entering the Northeast. As the period ended, however, enough moisture from an upper-air low off the southern California coast raised humidity levels, lowered winds and generated widely scattered showers in the West, which aided firefighters battling the huge wild fire in the southern California coastal mountains.

Farther east, the slow-moving storm was creeping northeastward into the mid-Atlantic. Most of the lower 48 states and Alaska recorded subnormal weekly temperatures, especially the Plains, with unseasonable warmth confined to the West, Southwest, eastern Great Lakes region, Ohio Valley and New England.

Looking Ahead: The next five days (May 9-13) favor wet weather across most of the eastern half of the Nation, with the heaviest totals expected in Colorado, from central Texas eastward to the Florida Panhandle, and from eastern Kansas northeastward into New England, with over 2 inches predicted in the latter area. Little or no rain is expected in most of the West, Southwest, north-central Plains, and upper Great Lakes region. Temperatures should average above normal in the Far West, Great Basin and northern Rockies, and below normal in the eastern half of the U.S. and southern Rockies.

For the ensuing five days (May 14-18), the odds favor above median precipitation in the southern High Plains (New Mexico and western Texas) and the northeastern quarter of the country. The highest probabilities for submedian rainfall include the Southeast, and from eastern Nevada to western Nebraska. Elsewhere there is no tilt in the odds. Probabilities for above-median temperatures are highest in the western half of the U.S., especially the Southwest, while submedian readings are most likely in the southeastern quarter of the Nation.


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