NCDC / Climate Monitoring / Climate of 2003 / Annual / Drought / Search / Help
|
National Oceanic and Atmospheric Administration
Climate of 2003 - Annual Review U.S. Drought
National Climatic Data Center January 15, 2004
|
|
The data presented in this drought report are preliminary. Ranks, anomalies, and percent areas may change as more complete data are received and processed.
National Drought Overview
As the year began, moderate to extreme drought* covered one-third of the contiguous United States including much of the West and parts of the central and northern Plains to central Great Lakes. Precipitation in many of the drought areas during the subsequent five months resulted in a decrease of the drought area to about 20 percent by June. The combination of generally warmer- and drier-than-average conditions during the following four months led to an increase in the areal coverage to about 41 percent by October. Generally wetter conditions near the end of the year caused a decrease in the drought area to about 31 percent by the end of December. The percent area of the nation in severe to extreme drought followed a similar pattern throughout the year.
|
larger image
|
*This drought statistic is based on the Palmer Drought Index, a widely used measure of drought. The Palmer Drought Index uses numerical values derived from weather and climate data to classify moisture conditions throughout the contiguous United States and includes drought categories on a scale from mild to moderate, severe and extreme.
The most extensive national drought coverage during the past 100 years (the period of instrumental record) occurred in July 1934 when 80 percent of the contiguous U.S. was in moderate to extreme drought. Although the current drought and others of the 20th century have been widespread and of lengthy duration, tree ring records indicate that the severity of these droughts was likely surpassed by other droughts including that of the 1570s and 1580s over much of the western U.S. and northern Mexico.
|
Regional Drought Overview
Spring was very dry in the southern Plains, with Texas experiencing the driest March-May in the 109-year record during 2003.
|
At year's end, moderate to extreme drought covered approximately 56 percent of the western states from the Rockies to the Pacific coast. During the peak of the 2003 drought, about 80 percent of this region was affected, which rivals the extensive drought area of the worst 20th century droughts. A major late winter storm dumped near-record snowfall on parts of the central Rockies, bringing snow water content to near or slightly above average, and a series of winter storms late in the year brought above-average rain and snow to parts of the West. Short-term relief resulted from these systems, but the moisture deficits in the West were so great from three to five years of drought that many more months of above-average precipitation are needed to end the drought in much of the region.
|
Pre-instrumental Drought Perspective
Tree ring records provide a useful paleoclimatic index that extends our historical perspective of droughts centuries beyond the approximately 100-year instrumental record. Several paleoclimatic studies have shown that droughts as severe or worse, both in magnitude and duration, than the major 20th century droughts have occurred in the U.S. during the last thousand years. The following paleodrought reports have been prepared by the NOAA/NCDC Paleoclimatology and Climate Monitoring branchs during 2003:
- Northeast Arizona, 1000-2003
- Great Salt Lake, Utah, 1847-2003
- Southeast Colorado, 1534-2003
- Northeast Utah, 1405-2003
- New Mexico-Arizona fire scar chronology, 1600-present
- El Malpais site, New Mexico, 136 BC - 2003 AD
- Northern Rockies, 1306-2003
- Central Plains, 1460-2003
- Upper Colorado River, 1437-2002
- Columbia River Basin, 1750-2003
|
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 2003 / Annual / Drought / Search / Help
http://www.ncdc.noaa.gov/oa/climate/research/2003/ann/drought-summary.html
Downloaded Thursday, 25-Sep-2008 14:06:03 EDT
Last Updated Friday, 18-Nov-2005 14:11:34 EST by Richard.Heim@noaa.gov
Please see the NCDC Contact Page if you have questions or comments.
|
|