Drought - October 2007


NCDC transitioned to the nClimDiv dataset on Thursday, March 13, 2014. This was 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.

Contents Of This Report:
Map showing Palmer Z Index

Top of Page National Overview

  • 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 quotes).
  • Based on the U.S. Drought Monitor, at the end of October, moderate to exceptional drought affected about 67 percent of the Southeast, 57 percent of the West, and 35 percent of the contiguous U.S.


Top of Page Detailed Drought Discussion


During October 2007, beneficial rain fell across parts of the Southeast, but the rain missed a large part of the core drought area. Meanwhile, the southern Plains to Southwest was drier than normal. Long-term drought conditions continued across much of the Southeast and West, with spotty patches of drought in other parts of the country.

Most of the stations in Alaska were drier than normal during the month. October was dry for most of the Hawaiian Islands, continuing a dry pattern that has lasted several months. The northwestern portion of Puerto Rico was drier than normal during October, but above-normal rainfall occurred over the southeastern sections which have seen persistently below-normal conditions for several months.

A subtropical high pressure system has been responsible for blocking rainfall across much of the Southeast during the spring and summer and now into the fall. Significant moisture deficits have built up over the last several months (3 months, 6 months, 9 months, 12 months), reaching record and near-record levels for some states.
About 42 percent of the western U.S. (Rockies westward) fell in the moderate to extreme drought category, and about a third fell in the severe to extreme category (as defined by the Palmer Drought Index) by the end of this month.

The persistent dryness has depleted soil moisture, ravaged pastures, and dried up streams. Soil moisture (both modeled and observed) and streamflow (both modeled and observed) were most severely affected in the three core drought areas: the Southeast, upper Great Lakes, and West.
Map showing 9-Month Standardized Precipitation Index

A more detailed drought discussion can be found below.



SOUTHEAST DROUGHT

As summarized by the Southeast Regional Climate Center, drought persisted across much of the Southeast during October, particularly in an arc stretching from western Virginia through the western Carolinas to northern Georgia and northeast Alabama. There was some relief on October 24-26 when an upper-level low pressure system to the west brought 2 to 6 inches of rain over much of the area. As a result, the area in the D4 (Exceptional Drought on the U.S. Drought Monitor) category, which had been increasing early in the month, decreased slightly. At month's end, slightly less then a third of the region was still in Exceptional Drought, although more than half was covered either by Extreme or Exceptional Drought conditions. Only the northeastern and the southern parts of the region saw an overall improvement as the month progressed. For rainfall year-to-date values, many stations were hovering around the second or third driest on record. For example, so far (as of November 7) in 2007 Atlanta has received a total of 26.11 inches of rain, the third driest year-to-date on record, behind 1931 (23.61") and 1954 (24.68"). And the official National Weather Service forecast suggests that, during the next few months, the drought conditions will at least persist, and possibly intensify, for all areas of the Southeast.

Some specifics:
  • Several deep wells, ponds, and springs in the Southeast have dried up.
  • Streams were at record or near record low levels, with some at flow levels half the previous record low.
  • Reservoirs that supply water to major urban centers continued to drop, with some areas (such as Atlanta, GA and several communities in NC) having as little as three months of water supply remaining. Many cities in the region have instituted mandatory water restrictions. In North Carolina, Gov. Easley has said, "If we do not get significant rain, some areas face the once unthinkable possibility of water rationing and potentially running out of water entirely." Low water levels in Lake Lanier, which services Atlanta, prompted a meeting between the governors of Georgia, Alabama, and Florida, and other interests, to modify water management practices for the water in Lake Lanier.


NORTHEAST DROUGHT

Governor Rell issued a drought advisory for the state of Connecticut on October 5. The officials in several Connecticut towns enacted emergency rules encouraging water conservation.

Delaware's Governor Minner requested drought disaster relief from the USDA in September and, in mid-October, issued a statewide drought watch urging residents to voluntarily conserve water.

OTHER AREAS

According to a University of Nebraska report, levels in Lake Mead (in the Southwest U.S.) continued to fall. The October 2007 Lake Mead level was at 1111.1 feet, which is 15 feet lower than this time last year, the lowest October level since 1964, and the fourth lowest October level in 70 years of record.



Top of Page State/Regional/National Moisture Status


A detailed review of drought and moisture conditions is available for all contiguous U.S. states, the nine standard regions, and the nation (contiguous U.S.):

STATES:
Alabama Arizona Arkansas California Colorado Connecticut
Delaware Florida Georgia Idaho Illinois Indiana
Iowa Kansas Kentucky Louisiana Maine Maryland
Massachusetts Michigan Minnesota Mississippi Missouri Montana
Nebraska Nevada New Hampshire New Jersey New Mexico New York
North Carolina North Dakota Ohio Oklahoma Oregon Pennsylvania
Rhode Island South Carolina South Dakota Tennessee Texas Utah
Vermont Virginia Washington West Virginia Wisconsin Wyoming


REGIONS:
Northeast Region East North Central Region Central Region
Southeast Region West North Central Region South Region
Southwest Region Northwest Region West Region
Map showing the nine U.S. standard regions
NATIONAL:
Contiguous U.S.




Top of Page Pre-Instrumental Perspective


There is no October 2007 Paleoclimatic Perspective.

Citing This Report

NOAA National Climatic Data Center, State of the Climate: Drought for October 2007, published online November 2007, retrieved on October 22, 2014 from http://www.ncdc.noaa.gov/sotc/drought/2007/oct.