Bloomberg News

U.S. Drought Monitor Report for the Week Ending Dec. 4 (Text)

December 06, 2012

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.

To contact the reporter on this story: Stephen Rose in Washington at srose31@bloomberg.net

To contact the editor responsible for this story: Marco Babic at mbabic@bloomberg.net


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