Bloomberg News

U.S. Drought Monitor Report for the Week Ending Nov. 27 (Text)

November 29, 2012

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

Summary:  Mostly dry weather prevailed across drought areas of
the contiguous U.S., with above-normal temperatures across the
western half of the nation contrasting with near- to below-
normal temperatures east of the Mississippi.  Locally heavy rain
and mountain snow persisted, however, across the central and
northern Pacific Coast states as well as the northern Rockies.
Meanwhile, a disturbance generated beneficial showers late in
the period from the western and central Gulf Coast into the
lower Ohio River Valley, although amounts were generally too
light to afford any notable drought reduction.  Rain from this
system had not yet reached the Southeast as of the Tuesday
morning cutoff for inclusion in this analysis; any potential
benefits from the Southeastern rainfall will be addressed in
next week’s Drought Monitor.

Mid-Atlantic and Northeast:  Mostly dry, cool weather continued.
Abnormal Dryness (D0) was introduced along the Vermont-New
Hampshire border to reflect declining streamflows as well as
increasing precipitation deficits (locally less than 50 percent
of normal over the past 60 days).  Farther south, Moderate
Drought (D1) expanded across southern Virginia, where 90-day
rainfall has tallied less than 60 percent of normal and
streamflows have likewise dropped into the 10th percentile or
lower.

Southeast:  Despite cooler-than-normal weather, conditions
deteriorated across much of the region.  It is important to note
the rain which fell over the Southeast Tuesday into Wednesday
did so after the Tuesday morning (8 am, EST) cutoff for this
week’s U.S. Drought Monitor (USDM); the impacts of this rain --
if any -- will be addressed in next week’s issuance of the USDM.
Abnormal dryness and drought expanded or intensified from the
Carolinas into northern Florida.  A disturbance triggered
showers (0.5 to 1 inch) in west-central Alabama, preventing
drought expansion in this locale for the time being.  Elsewhere,
rainfall over the past two months has totaled less than 50
percent of normal (locally less than 25 percent of normal) from
northern Florida and southern Alabama northeastward across much
of Georgia into central portions of the Carolinas.  Streamflows
across much of the Southeast -- excluding central and southern
Florida -- are in the 5th percentile or lower.  Further
illustrating the drought’s increasing impacts, pastures rated
poor to very poor in Georgia have jumped from 29 to 53 percent
over the past month (as of November 25), while winter wheat
emergence in North Carolina stood at 45 percent as of November
25, 13 points behind last year and 7 percentage points behind
the 5-year average.

Delta:  Late-period showers provided a temporary reprieve from
drought expansion, although Abnormally Dry conditions (D0)
expanded in northeastern Louisiana where rain was generally
light.  Showers were heaviest (1-2 inches) in far northern
Louisiana and central Mississippi, preventing any expansion of
D0 across these locales.  Lighter showers (0.5 to 1 inch) also
fell across southern Louisiana, preventing expansion of Moderate
Drought (D1) or Abnormal Dryness; however, if additional rain
does not fall across the southern Delta soon, drought will
likely intensify and expand.  Streamflows are lowest in
southwestern Louisiana (5th percentile or lower), and have been
on the decline across the rest of the region in response to a
drier-than-normal November.

South-Central U.S.:  With the exception of far-southern Texas,
drought intensified across much of the region as rainfall
deficits mounted and soil moisture, streamflows, and other water
reserves rapidly declined.  The rain (0.5 to 2 inches), which
fell primarily in the Lower Rio Grande Valley, afforded some
modest reductions in Extreme Drought (D3) near and to the east
of Laredo.   Otherwise, widespread drought intensification was
noted from southeastern Texas northward into Oklahoma, with
substantial increases in the coverage of Extreme (D3) to
Exceptional (D4) Drought in northern Texas and southern and
eastern Oklahoma.  The drought’s impacts are far reaching, and
are noted in the region’s agricultural reports.  As of November
25, the Texas winter wheat crop was rated 40 percent poor to
very poor, a 15-point jump from last week.  Meanwhile, the
state’s pastures have deteriorated from 43 percent poor to very
poor in late October to 53 percent poor to very poor as of
November 25.  In Oklahoma, winter wheat and pastures stood at 44
and 80 percent poor to very poor, respectively.  High-
resolution, satellite-derived Vegetation Health Index (VHI) data
indicated the worst conditions were entrenched both west of
Corpus Christi and west of San Antonio, Texas, while a larger,
more contiguous area of poor vegetative health extended from
Lubbock, Texas northward into the Oklahoma Panhandle and
eastward toward Ponca City, Oklahoma, along the Kansas border.

Central and Northern Plains:  Unseasonably mild, dry conditions
maintained or increased drought across much of the region,
although a swath of light to moderate snow (0.25 to 1.0 inch
liquid equivalent) afforded localized drought relief in
southwestern South Dakota.  The most notable changes were the
expansion of Exceptional Drought (D4) in southern Kansas as well
as an increase in Severe to Exceptional Drought (D2-D4) in
central and northeastern South Dakota.  Over the past 90 days,
rainfall has totaled less than 25 percent of normal from south-
central Nebraska northward into central South Dakota.
Illustrating the drought’s impacts, winter wheat was rated 64
and 25 percent poor to very poor in South Dakota and Kansas,
respectively, as of November 25, while Kansas’ pastures were
rated 82 percent poor to very poor.  Extreme to Exceptional
Drought (D3-D4) also continued to afflict eastern Colorado,
where pastures were rated 85 percent poor to very poor as of
November 25.  A small decrease in Exceptional Drought (D4) was
made to southwestern South Dakota, where updated data and input
from the field indicated some improvement; precipitation
(including some snow) in this corner of the state has been near-
to above-normal over the past 30 to 60 days.

Midwest/Tennessee Valley:  Dry weather resulted in increases in
drought intensity and coverage, although some showers were noted
in southern portions of the region.  Rain (0.25 to 1 inch) was
generally confined to a pair of narrow bands, one extending
across western and central Kentucky and the other across
southwestern and central Tennessee.  Otherwise, dry weather
prevailed.  Consequently, modest increases in D0 (Abnormal
Dryness) and Moderate Drought (D1) were made to reflect
increasingly dry conditions at 30 and 60 days as well as
declining streamflows (20th percentile or lower) in eastern
Tennessee, central and northern Kentucky, as well as neighboring
portions of southern Illinois, Indiana, and Ohio.  Farther
north, a tight gradient exists between favorable rainfall over
the past 90 days in central portions of Illinois and Indiana
with sharply drier conditions (locally less than 50 percent of
normal over the past 90 days) from northern Illinois into
northern Indiana and southern Michigan.  Many streamflows in
these locales are currently in the 5th percentile or lower.
Declining streamflows and increasing short-term precipitation
deficits also resulted in the expansion of Abnormal Dryness (D0)
across central and eastern Michigan as well as Moderate Drought
(D1) in western sections of Michigan’s Upper Peninsula.   In the
upper Midwest, Moderate to Severe Drought (D1 and D2) were
expanded across northern Minnesota and northwestern Wisconsin,
where short-term precipitation deficits were causing rapid
declines in soil moisture and streamflows.  The lingering
benefits of a single heavy rain event in northeastern Minnesota
during mid-June have been steadily undone by extremely dry
conditions during the rest of the summer and autumn.

Western U.S.:  Stormy conditions continued to provide beneficial
precipitation across western and northern portions of the
region, while dry, unfavorably warm weather prevailed over
central and southern drought areas of the west.

From central California into the northern Rockies and Northwest,
Pacific moisture continued to fuel locally heavy rain and high-
elevation snow (2 to 6 inches liquid equivalent, locally more),
maintaining a favorable start to the winter wet season.
However, high snow levels were reflected in the generally low
Snow Water Equivalent (SWE) rankings; across the southern
Cascades and northern Rockies, many SNOTEL sites are in the
lowest 50th percentile, with some stations in the 20th
percentile or lower.  This is in sharp contrast to the
precipitation rankings, which are almost all in the upper 50th
percentile, with many stations in the 80th percentile or higher.
Consequently, snowpacks are off to a poor start despite the wet
weather pattern.  Nevertheless, the heavy precipitation (mostly
rain) resulted in some decrease of D0 (Abnormal Dryness) and D1
(Moderate Drought) in northern California.

In central and southern portions of the region, warm, dry
weather maintained or intensified drought.  Unlike areas farther
north, the water year has gotten off to a poor start from
central and southern California into the Four Corners region.
Precipitation over the past 90 days has totaled less than 50
percent of normal, with some locales reporting less than 25
percent of normal.  These short-term deficits coupled with
lingering long-term water shortages led to an increase of
Moderate to Severe Drought (D1-D2) from southern California into
western New Mexico, while an area of Extreme Drought (D3) was
introduced in southwestern Arizona to reflect the greatest
negative departures (locally less than 10 percent of normal over
the past 90 days).   In central Colorado, SNOTEL precipitation
and Snow Water Equivalent (SWE) rankings were mostly in the
lowest 10th percentile, with many stations slipping below the
5th percentile.  Consequently, Extreme Drought (D3) was expanded
to reflect the increasingly dry conditions.

Alaska, Hawaii, and Puerto Rico:  In Alaska, cold, dry
conditions continued, with temperatures averaging up to 10°F
below normal.  Dry weather has intensified over the past 60
days, and the increasing precipitation deficits along with
declining SNOTEL Snow Water Equivalents (in the 20th percentile
or lower across southern Alaska) led to an expansion of Abnormal
Dryness (D0).  In Hawaii, significant rain (1 to 4 inches) fell
in some drought areas; however, it remains it’s too early to
tell if it was enough to show improvement.   There were no
concerns for drought on Puerto Rico, with moderate to heavy rain
(2-6 inches) reported across central and eastern sections of the
island.

Looking Ahead:  Pacific moisture will continue to stream
onshore, resulting in moderate to heavy rain and high-elevation
snow (locally more than 12 inches, liquid equivalent) from
central California into the Northwest and northern Rockies.
Farther east, a weak cold front may bring some light showers to
the Mississippi Valley late in the period, while light showers
are possible in southern Texas.  Otherwise, dry, warm conditions
are expected across the remainder of the contiguous U.S.,
affording most drought areas little -- if any -- relief over the
next 5 to 7 days.  The CPC 6-10 day forecast for December 4-8
calls for above-normal temperatures across much of the nation,
with cooler-than-normal weather confined to Southeastern Coastal
areas.  Drier-than-normal weather is expected to persist from
the Four Corners region into the central and southern Plains and
Southeast, while wetter-than-normal conditions prevail across
the northern third of the nation.

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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