Dec. 6 (Bloomberg) -- Following is the text of the weekly U.S. Drought Monitor as released by the National Drought Mitigation Center in Lincoln, Nebraska:
An intense storm moved inland from the Pacific Ocean this week, bringing widespread heavy precipitation to central and northern California, the Pacific Northwest, the northern Intermountain West, and parts of the northwestern Rockies. Totals of 1 to 2 feet (liquid equivalent) were fairly common in the higher elevations and in some areas near the coast. In contrast, mild and dry weather prevailed across the rest of the country. Most locations reported less than 0.25 inch of precipitation for the week, with totals of 0.5 to 2.0 inches restricted to portions of northwestern New England, northern New York, the Lower Peninsula of Michigan, areas in and adjacent to central and southwestern Missouri, the central Ohio Valley, and part of the Southeast. The Northeast: Light precipitation left D0 conditions unchanged in northern sections of New York, Vermont, and New Hampshire. In the past 90 days, precipitation amounts were 2 to 8 inches below normal, with most locations reporting 4- to 6-inch deficits for the period. The Southeast: Dry and warm weather dominated areas from the Ohio and lower Mississippi Valleys eastward to the Atlantic Seaboard. Only the middle Ohio Valley and a swath from the Louisiana Delta northeastward through southeastern South Carolina received more than 0.25 inch of precipitation for the week. A few isolated sites picked up as much as an inch of rain. Widespread below-normal precipitation has been observed for at least the last 60 days throughout the region. Precipitation totals were 2 or more inches below normal almost everywhere in the region, and deficits of 4 to locally 8 inches accrued across most of Mississippi, Alabama, the Florida Panhandle, and the south Atlantic states away from the immediate coast. As a result, dryness and drought intensified through portions of the region. D0 was introduced along the central Gulf Coast and across parts of the Appalachians. In addition, following ample summer and early autumn precipitation, less than 0.5 inch of rain has fallen on the Florida Peninsula since the beginning of November, prompting the introduction of D0 (short-term) in the driest areas on the southwestern side of the Peninsula. Elsewhere, D1 expanded to cover larger sections of southern Virginia, the Carolinas, and eastern Alabama while the areas of D2 to D4 in South Carolina and Georgia also increased in size. Over the last 6 months, precipitation shortfalls of 12 to 20 inches have accumulated in east-central Alabama and at scattered locations in Georgia and the Carolinas. The Great Lakes Region: Light to moderate precipitation fell on most of Michigan and northwestern Indiana last week, with amounts reaching 1 to 2 inches in a swath across the central Lower Peninsula. Relief, however, did not seem sufficient to change the D0 or D1 conditions existing where the rain fell. Elsewhere in the region, little or no precipitation fell, leading to some D1 expansion south of Chicago, IL. The depiction is unchanged elsewhere. The Plains and Mississippi Valley: Precipitation for the week totaled less than 0.25 inch throughout the region, save for a small swath from the Arkansas/Missouri/Oklahoma triple point northeastward through parts of the St. Louis, MO area, where amounts reached 2 inches in a couple of isolated locations. Areas of dryness and drought remained unchanged for most of the region, given the cooler and drier time of year. However, areas of deterioration were identified across various parts of Texas, central Louisiana, east-central Missouri, eastern Kansas, and the Panhandles of Texas and Oklahoma. From southeastern Texas through central Louisiana, D1 and D2 expanded to cover areas where precipitation deficits for the last 90 days ranged from 8 to 14 inches. In the Panhandles region, D4 coverage increased as dryland wheat conditions deteriorated. Dalhart, TX received 6.04 inches of rain in 2011 and 6.35 inches to date in 2012. Both of these totals are more than 2 inches below the driest year on record for the previous 62 years (1949-2010; record low for this period was 8.37 inches in 1955). Mississippi River flow continued to decline, and it may be necessary to close parts of the river to barge and shipping traffic at some point. The U.S. Army Corps of Engineers is undertaking dredging and blasting operations in an effort to keep as much of the river navigable for as long as possible. The West: A powerful, slow-moving storm system brought widespread heavy precipitation to the Pacific Northwest, the northern Intermountain West, the northwestern Rockies, the western Great Basin, central and northern California, and parts of coastal California as far south as Los Angeles County. Storm total precipitation reached as high as 1 to 2 feet in the northern half of the Sierra Nevada, the southern Cascades, coastal sections of northwestern California and southwestern Oregon, and across the Olympic Range and its windward west- facing slopes in northwestern Washington. Scattered totals exceeding 12 inches were also reported along parts of the California coast from Monterrey County northward, and at a few locations near the coast in northwestern Oregon and western Washington. Meanwhile, 4 to locally 10 inches fell on the mountains in central and northeastern Idaho, the windward slopes of the Cascades, and the rest of California west of the mountains from the Sacramento Valley northward. More than an inch of precipitation fell along the California Coast as far south as Los Angeles County. In other parts of the West, away from the influence of this storm, little or no precipitation fell. Substantial drought relief was effected by the potent storm system. D0 to D2 conditions were all suppressed southward in western Montana, central Idaho, east-central Oregon, and the northern two-thirds of California. In addition, D2-D3 conditions pulled eastward away from the eastern side of the central and northern Sierra Nevada, including the Lake Tahoe region. The dry weather in the rest of the West brought little change to the widespread areas of dryness and drought, though some deterioration was identified in the eastern half of Colorado. Hawaii, Alaska, and Puerto Rico: Dryness intensified on much of the Big Island of Hawaii, with D1 expanding to cover most of the island. Water recently stopped flowing over Rainbow Falls near Hilo, HI, a rare but not unprecedented occurrence. Meanwhile, rainfall improved conditions from D3 to D2 along a small stretch near central Maui. Elsewhere, the depiction was not changed. No change was made in Alaska as the ground has frozen for the season. Conditions will be assessed during the late spring thaw. There is no dryness or drought in Puerto Rico. Looking Ahead: During the next 5 days (December 6 - 10, 2012), a storm system is forecast to traverse the Ohio and lower Mississippi Valleys, bringing at least an inch of rain to a broad area from parts of Mississippi and Arkansas near the Mississippi River northeastward through the Ohio Valley, parts of the southeastern Great Lakes Region, and the northern Appalachians. Amounts of 2 to 4 inches are possible from near the Mississippi/Ohio confluence northeastward through part of western New York. Farther west, light to moderate precipitation is expected across the central and northern Rockies, the central and northern Intermountain West and the Pacific Northwest, with totals of 1 to 3 inches possible in some higher elevations. Elsewhere, moderate precipitation totals of 0.5 to 1.0 inch are forecast for the central Great Lakes Region, the eastern side of the Mississippi Valley south of Wisconsin, southern Florida, and much of the upper Southeast and interior Northeast. Light precipitation is expected across the Plains outside of Texas, along the southern Atlantic Seaboard, and in portions of the Great Basin and central California. Little or none is expected elsewhere. Temperatures should average near or above normal throughout the contiguous 48 states, with average daily highs expected to be 9 to 12 degrees F above normal from the upper Ohio Valley and adjacent Appalachians southwestward into the lower Mississippi Valley. For the 6-10 day outlook (December 11 - 15, 2012), odds favor above-normal precipitation along the northern tier of states, and from southeastern Texas, the lower Mississippi Valley, the Ohio Valley, and the Great Lakes Region eastward to the Atlantic Coast. Below-normal precipitation is favored across roughly the southwestern quarter of the contiguous 48 states and in the central Great Plains. Warmer than normal weather should continue across the northeastern quarter of the contiguous 48 states and in the south-central Plains.
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