Drought - August 2001


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U.S. Drought Highlights:

Contents Of This Report:


National Overview

On the national scale,
  • severe drought affected about 18 percent of the contiguous United States as of the end of August 2001;
  • the total drought area has held steady at about 9 to 19 percent for the last eleven months (see graph below left);
  • the coverage of the current drought peaked in August 2000 at about 36% of the contiguous U.S., which was as extensive as the major droughts of the last 40 years, but not as large as the "dust bowl" droughts of the 1930's and 1950's;
  • on a broad scale, the last two decades were characterized by unusual wetness with short periods of extensive droughts, whereas the 1930's and 1950's were characterized by prolonged periods of extensive droughts with little wetness (see graph below right);
  • although different parts of the U.S. have experienced unusually wet conditions during the last 23 months, there continues to be little change in the overall national wetness picture;
  • the percentage of the nation severely wet has held steady at about three to eleven percent during this period (see graph below left);
  • a file containing the national monthly percent area severely dry and wet from 1900 to present is available.
 graphic showing U.S. Drought and Wet Spell Area, 1996-2001
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 graphic showing U.S. Drought and Wet Spell Area, 1900-2001
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Although some areas of the U.S. had well above normal precipitation, many areas were very dry. August averaged slightly below normal when precipitation is integrated across the nation. Eleven of the last 25 months have averaged well below the normal, while only three averaged well above normal (see graph to right). National 2001 precipitation ranks:  graphic showing U.S. Precipitation Departure and Normals, January 1998-August 2001
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Regional Overview

A potent Pacific storm system brought heavy rainfall to coastal Washington and Oregon in the middle of the month, however most of the western U.S. suffered from hot and dry weather during August, resulting in a continuation of drought conditions and a flare-up of wildfires in several states. A series of cold fronts brought drought relief to parts of the Great Lakes and Northeast, but the month still averaged hot and dry in many areas, continuing long-term moisture deficits there. In spite of heavy rains from Tropical Storm Barry early in the month, August precipitation totals were below normal across sections of Florida to the Carolinas, where patchy long-term drought persisted. Tropical moisture brought copious rainfall to parts of the southern Plains, bringing limited drought relief to parts of Texas, but severe drought continued across parts of Oklahoma and Arkansas. The drought signal was mixed in Alaska and Hawaii, with some stations having below-normal precipitation during August and others reporting a wetter-than-normal month. August was severely dry across parts of the northern Plains, interrupting a long-term wet spell in the region. This overall pattern is evident in: Two other drought-related monitoring tools are the Vegetation Health Index and the Keetch-Byram Drought Index:
  • NOAA satellite observations of vegetation health from late August revealed continued stress on vegetation in parts of the West, southern Plains, Northeast, and Great Lakes.
  • The Keetch-Byram Drought Index (KBDI) is used by the National Interagency Fire Center to monitor the risk of wildfires. The late August KBDI showed dry conditions in the southern Plains, parts of the West, and extreme Southeast. The Forest Service fire danger analysis indicated a continuing risk of wildfires in the western U.S. by the end of August.


Top of Page Western U.S. Drought

Rainfall across much of the western U.S. was well below normal during August as evidenced by the station precipitation reports, statewide precipitation ranks, and Palmer Z Index. Montana had the third driest August and Idaho the fifth driest August in the 107-year record, based on preliminary reports. Highlights:
  • The combination of hot, dry, windy conditions and high-altitude dry thunderstorms sparked thousands of new wildfires. During the first 20 days of August, about 1.23 million acres were blackened in the Great Basin, Pacific Northwest, and northern California, increasing the national year-to-date total to 2.83 million acres (103% of the 10-year average).
  • Stream flows and lakes continued to decline and, by mid-month, were generally at much below normal or near-record low levels.
  • Conditions at over half of the pastures and ranges in California, Washington, Montana, and Idaho were rated at mid-August as very poor to poor by the USDA's National Agricultural Statistics Service.
  • Long-term moisture deficits remained severe, especially in the northwestern quarter of the country.
The summer is normally the dry season for the Pacific Northwest. Regional ranks for 2001:
  • a slightly drier-than-normal August regionwide (49th driest),
  • 45th wettest summer (June-August),
  • third or fourth driest rank for the 8-month through 12-month periods (see table to right).
Declared drought emergencies continued in three western states (Washington, Oregon, and Idaho). Record or near-record low streamflows and reservoirs were stressing agricultural and other interests. In Idaho, groundwater users and surface irrigators reached agreement on water use before intervention by the Idaho Department of Water Resources was required.
Precipitation Ranks for the
Northwest Region, 2000-2001
Period Rank
Aug 49th driest
Jul-Aug 50th wettest
( 58th driest)
Jun-Aug 45th wettest
( 62nd driest)
May-Aug 36th driest
Apr-Aug 48th driest
Mar-Aug 35th driest
Feb-Aug 9th driest
Jan-Aug 4th driest
Dec-Aug 3rd driest
Nov-Aug 3rd driest
Oct-Aug 3rd driest
Sep-Aug 4th driest
 graphic showing Pacific Northwest Region Precipitation Anomalies, January 1998 - August 2001
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 graphic showing Pacific Northwest Region Precipitation, September-August, 1895-2001
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August rainfall averaged across the West region was below normal (see graph below left). Since the summer is the dry season for this region, the actual rainfall amounts were small. However, long-term drought conditions remain severe. August rainfall was near normal for the Southwest region (see graph below right). Some 2001 ranks for the ...
... West region: ... Southwest region:

 graphic showing West Region Precipitation Anomalies, January 1998 - August 2001
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 graphic showing Southwest Region Precipitation Anomalies, January 1998 - August 2001
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Top of Page Southeast and Great Plains Drought

Heavy rains improved drought conditions over parts of the southern Plains and Gulf coastal states during August. Above-normal rain fell across much of Texas, although drought continued over parts of Oklahoma and Arkansas (see maps below). Rainfall averaged across the South region was above normal for August.

 graphic showing U.S. short-term drought areas, August 2001
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 graphic showing U.S. hydrologic drought areas, August 2001
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Heavy rains from Tropical Storm Barry brought drought relief to Florida early in the month, but total monthly precipitation for August was still below normal from sections of Florida to the Carolinas. Statewide precipitation ranks for August included 11th driest for South Carolina, 20th driest for Georgia, and 22nd driest for Florida.

Regionwide, the Southeast averaged below normal for August (see graph below left), with a rank of 34th driest. This year marked the fifth consecutive August with below average precipitation. With near to much above normal rainfall during June and July, summer (June-August) 2001 ranked 35th wettest, which is a break from the pattern of summer dryness of recent years. However, the region has suffered from severe drought for much of the last three and a half years (see graph below left). September 2000-August 2001 ranked as the 36th driest such period and marked the third consecutive September-August period with well below average precipitation (see graph below right).

 graphic showing Southeast Region Precipitation Anomalies, January 1998 - August 2001
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 graphic showing Southeast Region Precipitation, September-August, 1895-2001
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Two-year precipitation deficits remain severe in four areas: Florida, the southern Appalachians, parts of Texas, and the confluence of the Ohio and Mississippi rivers (see map to right). Rains from Tropical Storm Barry and earlier summer systems have helped recharge Florida aquifers, rivers, and lakes, but dryness returned later in the month. A few wells were near or at record low levels in Dade County, and Tampa experienced a 14-day dry spell which was the longest such dry stretch during August on record. Although Lake Okeechobee's level rose in response to the rains, it was still 2.7 feet below the 1979-1995 average in mid-August, or about the same level as August 2000. By the end of August in southern Texas, the two lakes on the Rio Grande that provide much of the municipal and irrigation water for the four counties at the southern tip of Texas were below 25% of conservation capacity, a threshold at which mandatory and/or voluntary conservation measures kick in for many communities and water districts.  map showing 24-month Standardized Precipitation Index, September 2000-August 2001
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An unusually dry August in the northern Great Plains (see graph below left) was a departure from the persistently wet conditions that have characterized this region for much of the last twelve months. The West North Central region had the third driest August in the 107-year record, contrasting with the 23rd wettest summer (June-August) and 36th wettest September-August. On a statewide basis (see map below right), South Dakota had the driest August on record, Montana third driest, and North Dakota 12th driest. In spite of the dry August conditions, long-term conditions remained very moist over much of the northern Plains.

 graphic showing West North Central Region Precipitation Anomalies, January 1998 - August 2001
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 map showing August 2001 Statewide Precipitation Ranks
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Top of Page Northeast and Great Lakes Region Drought

August 2001 was the second consecutive dry month over much of the Northeast and Great Lakes (East North Central) regions (see graphs below). Conditions were especially severe in parts of the Northeast. Some highlights:
  • 33rd driest August for the Northeast and 45th driest August for the East North Central regions;
  • 12th driest August for New Hampshire and 14th driest August for Maine;
  • eighth driest April-August, 12th driest January-August, and 15th driest September-August for the Northeast region;
  • Pennsylvania expanded their drought watch to include 45 counties in which the residents were asked to voluntarily cut back on water use due to low groundwater supplies;
  • groundwater supplies were impacted by the drought in parts of Vermont, requiring the drilling of new wells in places.

 graphic showing East North Central Region Precipitation Anomalies, January 1998 - August 2001
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 graphic showing Northeast Region Precipitation Anomalies, January 1998 - August 2001
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Top of Page Additional Contacts:

Damage due to the drought has been summarized by NOAA and the Office of Global Programs in the Climatological Impacts section of the Climate Information Project. Crop impact information can be found at the USDA NASS (National Agricultural Statistics Service) and Weekly Weather and Crop Bulletin pages. Drought statements by local National Weather Service Offices can be found at the NWS Hydrologic Information Center. Drought threat assessments and other information can be found at NOAA's Drought Information Center. Additional drought information can be found at the National Drought Mitigation Center, the USDA's National Agricultural Library, the interim National Drought Council, and the NOAA Paleoclimatology Program. The following states have set up web pages detailing current drought conditions and/or their plans to handle drought emergencies:
Delaware - Florida Panhandle - Georgia - Hawaii - Idaho - Kentucky - Maryland - Missouri - Montana - Nebraska - New Jersey - New Mexico - North Carolina - Oklahoma-1 - Oklahoma-2 - Pennsylvania-1 - Pennsylvania-2 - South Carolina - Texas - Washington

For additional information on the 2001 wildfire season please see the National Interagency Fire Center web site or the U.S. Forest Service Fire and Aviation web site.

NCDC's Drought Recovery Page shows the precipitation required to end or ameliorate droughts and the probability of receiving the required precipitation.

Additional climate monitoring graphics can be found at the Climate Prediction Center's monitoring pages:

Citing This Report

NOAA National Climatic Data Center, State of the Climate: Drought for August 2001, published online September 2001, retrieved on July 28, 2014 from http://www.ncdc.noaa.gov/sotc/drought/2001/8.