U.S. Drought Monitor Report for the Week Ending April 23 (Text)

Following is the text of the weekly U.S. Drought Monitor as released by the National Drought Mitigation Center in Lincoln, Nebraska:


Summary:  Chilly, unsettled weather across the central U.S.
contrasted with increasingly dry conditions in the west and
parts of the south.   Consequently, drought coverage deceased
from the upper Midwest into the western Corn Belt and central
portions of the Rockies and Great Plains, while drought
intensified and expanded from western Texas into northern
California and the Great Basin.  Showers also eased dryness in
southern Florida, while northern portions of the state wrestled
with moderate to severe drought.

Mid-Atlantic and Northeast:  Cool, showery weather prevailed
across the region, although 90-day precipitation deficits of 6
inches or more were noted in Connecticut where Abnormal Dryness
(D0) was introduced.  Short-term dryness in Pennsylvania has
abated somewhat, and another cool, wet week would likely ease D0
in most parts of the state.

Southeast:  Occasional showers along with near-normal
temperatures offered little significant change to the region’s
lingering D0 and D1 (Moderate Drought) areas.  However, updated
Standardized Precipitation Indices (SPI) and streamflow data
indicated the lingering long-term Abnormal Dryness in South
Carolina continued to abate, while this week’s rainfall (locally
more than an inch) was not enough to ease Moderate Drought in
North Carolina.   In Florida, widespread showers (1-4 inches)
eased D0 in southern portions of the state.  In contrast,
isolated, but locally heavy showers (locally in excess of 3
inches) were not sufficient in coverage to prevent a westward
expansion of Severe Drought (D2) from Ocala to the Gulf Coast;
streamflows and soil moisture in this region remained in the 5th
percentile or lower, indicating that 6-month rainfall deficits
of 10 inches or more continue to have an impact.

Midwest:  Heavy rain and wet snow eased long-term drought across
western and northern portions of the region.  Liquid-equivalent
precipitation of 1 to 3 inches from northern Minnesota into the
Upper Peninsula of Michigan eased D0 and D1 (Moderate Drought),
as these areas continued to emerge from drought.  From
southeastern Minnesota into central Iowa, northwestern Missouri,
and southeastern Nebraska, precipitation totals of 2 to 6 inches
resulted in additional, widespread reductions in drought
intensity and coverage.  However, precipitation totals were
somewhat less (1-2 inches) in northwestern Iowa and northeastern
Nebraska, where long-term Moderate to Severe (D1 -D2) Drought
persisted.

South-Central U.S.:  Beneficial rain from eastern Texas into the
southeastern Plains contrasted with increasing dryness from the
upper Rio Grande Valley onto the southern High Plains.  Rainfall
totals in northeastern Texas averaged an inch or more from the
Dallas-Ft. Worth metro area to Texarkana, which eased Moderate
to Severe Drought (D1-D2) in northeastern portions of the state.
A swath of locally heavy rainfall (2-5 inches) from the Wichita
Mountains in southwestern Oklahoma northeastward through
Oklahoma City and Tulsa alleviated Exceptional (D4) to Moderate
(D1) Drought, although significant, long-term deficits and
impacts continue.  Meanwhile, Moderate (D1) to Exceptional (D4)
Drought lingered or intensified from western Texas and
southeastern New Mexico into the Oklahoma Panhandle.  As of
April 21, 2013, the percent of the Plains’ winter wheat rated
poor to very poor stood at 36 percent in Oklahoma and 60 percent
in Texas.   Precipitation over the past 6 months has totaled
less than 40 percent of normal in the worst drought areas, with
some stations reporting less than 20 percent of normal.

Central and Northern Plains:  Drought intensified over the
central High Plains, while heavy rain and wet snow afforded
drought relief to eastern portions of the region.  Moderate to
heavy rain (2-3 inches) in Kansas eased drought in eastern and
north-central portions of the state, with totals approaching
3.50 inches near the Nebraska border.  Drought relief largely
bypassed central and western Nebraska, although upwards of an
inch (liquid equivalent) provided some topsoil moisture near
Alliance.   Precipitation totals over the northern Plains’
drought areas ranged from less than an inch in southern Montana
to locally more than 2 inches in the Black Hills of South
Dakota, where some reductions in drought intensity and coverage
were made.  Most of the Extreme (D3) or Exceptional (D4) Drought
areas received less than 0.50 inch, however, which led to
little, if any, change in the worst drought areas.  In Colorado,
D4 was expanded in the southeastern corner of the state where
90-day precipitation has tallied locally less than 20 percent of
normal; the Colorado winter wheat crop was rated 56 percent poor
to very poor as of April 21, 2013, while Kansas wheat stood at
37 percent.

Western U.S.:  The water year approached conclusion, with many
areas of the west ending the season with bleak spring runoff
prospects and increasing drought concerns.  Precipitation was
mostly confined to the non-drought areas of the Pacific
Northwest, where 1 to 3 inches (liquid equivalent) were reported
during the monitoring period.  Consequently, drought persisted
or expanded across much of the region.

From central California into the Great Basin and central
Rockies, the disappointing end to the water year resulted in
some expansion of drought.  In northeastern California and
southeastern Oregon, water-year precipitation averaged 50 to 70
percent of normal, with the corresponding Standardized
Precipitation Index (SPI) in this region over the same time
period indicating D1 (Moderate Drought or greater) .  In the
Sierra Nevada, where a promising start to the snow season was
followed by an abrupt reversal, the liquid Snow Water Equivalent
(SWE) dropped below the 15th percentile, with water-year
precipitation deficits averaging 3 to 11 inches near Lake Tahoe;
consequently, Moderate Drought (D1) was expanded to encompass
the central Sierra Nevada.   Severe Drought (D2) was expanded in
the San Juan Mountains of southwestern Colorado, as well as
neighboring environs, to reflect water-year precipitation values
that have dropped to nearly 50 percent of normal as well as SWE
which dropped into the 10th percentile or lower (corresponding
precipitation rankings were at or below the 5th percentile).
One exception was the central Rockies, where a late-season snow
storm (locally more than 2 inches liquid equivalent) eased
drought in central and northern Colorado.

Farther south, water-year precipitation shortfalls increased
from the southern San Joaquin Valley (40 to 55 percent of
normal)  into southwestern Nevada (30 to 50 percent of normal)
and western Arizona (less than 50 percent of normal) .
Consequently, Moderate (D1) to Severe (D2) Drought was expanded
in these locales.  Likewise, Extreme Drought (D3) was introduced
in southeastern Arizona and southwestern New Mexico, where
water-year precipitation totaled a meager 30 percent of normal
or less (deficits locally more than 4 inches).

Alaska, Hawaii, and Puerto Rico:  In Alaska, cold, dry
conditions continued, with temperatures averaging up to 10°F
below normal.  Streamflows in Alaska have exhibited some
recovery, although water-year precipitation remained in the
lowest 20th percentile in the state’s Moderate Drought (D1)
area.  In Hawaii, D0 was removed from east Oahu; the water level
in Waimanalo Reservoir continued to increase and is currently at
a pre-drought level.   In Puerto Rico, widespread showers (1- 4
inches) boosted streamflows, and should rain continue, some
improvement from Abnormal Dryness (D0) is likely in the next
several weeks.

Looking Ahead:  Warmer- and drier-than-normal conditions will
spread from the western U.S. eastward into the central and
northern Plains.  In contrast, a slow-moving, upper-air low will
bring wet, cool weather to the Southeast, although rain activity
will subside in Florida.  Showers are also expected in central
and southwestern Texas; however, the core Exception Drought (D4)
areas of the central and southern High Plains will mostly miss
the heaviest rainfall.  The CPC 6-10 day forecast for April 30 -
May 4 calls for warmer- and drier-than-normal weather across
much of the west, with dryness extending eastward into the
central Plains.  In contrast, above-normal precipitation and
near- to below-normal temperatures are expected across southern
portions of the Rockies and High Plains and from the eastern
Gulf Coast into the Great Lakes region.

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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