NCDC: U.S. Regional Drought Watch

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Climate of 2001 - September
U.S. Regional Drought Watch

National Climatic Data Center, 17 October 2001

Global Analysis / Global Regional / U.S. National / U.S. Regional / U.S. Drought / Extreme Events / Climanomics
Use these links to access detailed analyses of Global and U.S. data.

Regional Overview

Dry conditions in the western U.S., coupled with unusually hot temperatures this month, exacerbated the long-term drought over much of the region. Rain from a series of cold fronts brought relief to parts of the Northeast, however drought lingered in northern New England and along the Great Lakes. In the Southeast, heavy rains from Tropical Storm Gabrielle and a series of cold fronts ended drought over much of Florida, however areas of long-term moisture deficits remained from northern Florida to the Carolinas. Parts of the southern Plains were soaked by tropical moisture, but other areas were missed by the heavy rains. Drought persisted across parts of Texas and Arkansas. The drought signal was mixed in Alaska and Hawaii, with many stations having below-normal precipitation during September. This overall pattern is evident in:

the Palmer Indices and Standardized Precipitation Index,
the runoff and soil moisture conditions as calculated by the National Weather Service,
the statewide reports of percent of the topsoil very dry ("short" to "very short") provided by the U.S. Department of Agriculture,
the percent of normal precipitation map for September,
the percent of average precipitation map for the hydrologic year through September (October 1, 2000 - September 24, 2001) for the SNOTEL stations in the western mountains provided by the USDA Water and Climate Center,
the departure from normal of the number of days with precipitation map for September,
the statewide precipitation ranks for September (short-term) and July-September, April-September, and October 2000-September 2001 (longer-term), and
the USGS September daily streamflow maps.

Two other drought-related monitoring tools are the Vegetation Health Index and the Keetch-Byram Drought Index:

NOAA satellite observations of vegetation health from the end of September revealed continued stress on vegetation in parts of the West, Great Lakes, and western Texas.
The Keetch-Byram Drought Index (KBDI) is used by the National Interagency Fire Center to monitor the risk of wildfires. The late September KBDI showed dry conditions over much of the West, northern New England, and from Georgia to South Carolina in the Southeast. The Forest Service fire danger analysis indicated a continuing risk of wildfires in the western and southwestern U.S. by the end of September.

Western U.S. Drought

Rainfall across much of the western U.S. was below normal during September as evidenced by the station precipitation reports, statewide precipitation ranks, and Palmer Z Index. The month was characterized by unusually warm temperatures as well which exacerbated the drought, with streams and reservoirs reaching record or near-record low levels in many areas. Long-term moisture deficits remained severe, especially in the northwestern quarter of the country. Highlights:

Declared drought emergencies continued in three western states (Washington, Oregon, and Idaho).
The 2000-2001 water year (October 1-September 30) was the driest on record for many locations in northwest Oregon.
Reno, Nevada experienced the warmest September and driest water year on record.
On a regional and statewide basis, the 2000-2001 water year was the second driest for the Pacific Northwest, second driest for Washington, third driest for Oregon, and seventh driest for Idaho.

Percent of Normal Precipitation for September 2001

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Pacific Northwest Region Precipitation Anomalies, January 1998 - September 2001

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October 2000-September 2001 statewide precipitation ranks

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September was dry and unusually hot across much of the West and Southwest regions. July-September is normally the wet season for the Southwest (see graph below left). In 2001, the Southwest region had the ...

tenth warmest September,
21st driest September,

fifth warmest July-September, and
26th driest July-September.

Southwest Region Precipitation Anomalies, January 1998 - September 2001

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Southwest Region July-September Precipitation, 1895-2001

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Southeast and Great Plains Drought

Heavy rains fell across much of the area from Florida to eastern Texas and Oklahoma during September (see map below left). Short-term drought in Florida was vanquished, however low aquifers and long-term precipitation deficits persisted in northern Florida. Areas of long-term drought also continued in parts of Arkansas, Texas, and Georgia to the Carolinas (see map below right).

U.S. short-term drought areas, September 2001

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U.S. hydrologic drought areas, September 2001

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Despite the heavy rains of recent months, long-term conditions averaged across the Southeast region remained dry. The 2000-2001 water year ranked as the 26th driest October-September on record and marked the third consecutive water year with below average precipitation (see graph below right). Highlights:

third driest water year in the 106-year record for North Carolina
fourth driest water year and eighth driest April-September for South Carolina
sixth driest water year for Virginia
low stream and reservoir levels resulted in a total ban on outdoor water use in the city of Griffin, Georgia (south of Atlanta).

Southeast Region Precipitation Anomalies, January 1998 - September 2001

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Southeast Region Precipitation, October-September, 1895-2001

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Northeast and Great Lakes Region Drought

September 2001 was the third consecutive dry month for the Northeast region (see graph below left). Heavy rains brought relief to parts of the region, but drought persisted over northern New England and along the Great Lakes. Some highlights:

15th driest July-September and tenth driest October-September (see graph below right) regionwide.
Driest April-September in the 107-year record for Maine.
Second driest April-September for New Hampshire and Vermont.
The drought in the Northeast U.S. didn't stop at the border. Many Canadian farmers in Nova Scotia, parts of which have reportedly been affected by dry conditions 4 of the past 5 years, were considering giving up their livelihood altogether.

Northeast Region Precipitation Anomalies, January 1998 - September 2001

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Northeast Region Precipitation, October-September, 1895-2001

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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-1 - Montana-2 - Nebraska - New Jersey - New Mexico - North Carolina - Oklahoma-1 - Oklahoma-2 - Oregon-1 - Oregon-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:

For all climate questions other than questions concerning this report, please contact the National Climatic Data Center's Climate Services Division:

Climate Services Division
NOAA/National Climatic Data Center
151 Patton Avenue
Asheville, NC 28801-5001
fax: 828-271-4876
phone: 828-271-4800
email: ncdc.info@noaa.gov

For further information on the historical climate perspective presented in this report, contact:

Richard Heim
NOAA/National Climatic Data Center
151 Patton Avenue
Asheville, NC 28801-5001
fax: 828-271-4328
email: Richard.Heim@noaa.gov

-or-

Jay Lawrimore
NOAA/National Climatic Data Center
151 Patton Avenue
Asheville, NC 28801-5001
fax: 828-271-4328
email: Jay.Lawrimore@noaa.gov

NCDC / Climate Monitoring / Climate of 2001 / September / Search / Help

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Last Updated Monday, 11-Jul-2005 16:12:23 EDT by Richard.Heim@noaa.gov
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