NCDC will transition to the nClimDiv dataset on Thursday, March 13, 2014. This is coincident with the release of the February 2014 monthly monitoring report. For details on this transition, please visit our public FTP site and our U.S. Climate Divisional Database site.
- Based on the Palmer Drought Index,
severe to extreme drought affected about 18 percent of
the contiguous United States as of the end of April 2007, about
the same as last month. By
contrast, about 11 percent of the contiguous U.S. fell in the
severely to extremely wet
- About 30 percent of the
contiguous U.S. fell in the
moderate to extreme drought categories (based on the
Palmer Drought Index) at the end of April .
- On a broad scale, the previous two decades (1980s and 1990s)
were characterized by unusual wetness with short periods of
extensive droughts, whereas the 1930s and 1950s were characterized
by prolonged periods of extensive droughts with little wetness
to extreme drought,
severe to extreme drought).
- A file containing the national monthly percent area severely
dry and wet from 1900 to present is available for the severe to extreme and moderate to extreme categories.
- Historical temperature, precipitation, and Palmer drought data
from 1895 to present for climate divisions, states, and regions in
the contiguous U.S. are available at the Climate Division:
Temperature-Precipitation-Drought Data page in files having
names that start with "drd964x" and ending with "txt" (without the
Detailed Drought Discussion
|At the end of April
extreme drought was concentrated in the Southwest, the western High
Plains, northern Minnesota, and the Southeast. Drought and abnormal
dryness covered a broad swath from the Southwest through the
northwestern Plains into the upper Midwest, as well as another area
in most of the Southeast (May 1 Drought
Monitor). Conditions in southern California and southwestern
Arizona continued to deteriorate.
Storm systems throughout the month brought much needed
precipitation to the Plains and upper Midwest and eliminated the
drought conditions that had persisted for many months.
In the Southwest, Southeast and upper Midwest, soil
moisture was low. At the end of the month vegetation
was stressed over a large part of the country. Streamflow
was low in a wide area of the Southeast.
||Fires consumed over
50,000 acres in the Everglades in Florida in April. Low water
levels in southern Florida delayed construction activities, caused
increased silt in the intake of water supply systems, affected
sales of landscape and horticulture materials, and led to more
severe water usage restrictions. Alligators are being seen more
frequently as they move in search of wetter habitat.
In central California water deliveries are being postponed, and
farmers were affected by poor pastures and water shortages.
Governor Arnold Schwarzenegger warned the state to plan for drought
because the winter was extraordinarily dry. He also urged residents
to conserve water.
Twenty-one counties in southeastern Georgia are in a state of
emergency due to extreme fire danger from drought. A wildfire in
the southeast part of the state was the largest in the history of
Large ships on Lake Superior carried lighter loads to avoid
striking the bottom of the lake. Recreational boats and sailboats
had difficulty on Lake Superior because of low water levels. The
water became so shallow that rowers in the Duluth, Minnesota Rowing
Club could touch the bottom with their oars.
Impacts in drought-stricken areas have been collected and
summarized by county at the National Drought Mitigation Center's
Drought Impact Reporter.
State/Regional/National Moisture Status
There is no April 2007 Paleoclimatic