State of the Climate
Drought
February 2006
National Oceanic and Atmospheric Administration
National Climatic Data Center
Use the form below to access monthly reports.
U.S. Drought Highlights:
Please Note: 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 Overview
On the national scale,
- severe to extreme drought affected about 15 percent of the contiguous United States as of the end of February 2006, an increase of about 7 percent compared to last month
- about 25 percent
of the contiguous U.S. fell in the moderate to extreme drought categories (based on the Palmer Drought Index) at the end of February
- 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
- about 13 percent of the contiguous U.S. fell in the severely to extremely wet categories at the end of February
- a file containing the national monthly percent area severely dry and wet from 1900 to present is available
- 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).
Regional Overview
Dryness afflicted many of the same areas this month that have experienced dry conditions during the last several months (January, December, November). February was drier than normal in the southern Plains, from the southern Appalachians to mid-Atlantic coast, and in a broad swath from the Southwest across the central Plains to mid-Mississippi Valley. About 18 percent of the contiguous U.S. was very dry (i.e., precipitation in the bottom 10th percentile of the historical record).
Above-normal precipitation continued to bring improvement to parts of the northern Rockies and High Plains. Near the end of the month, beneficial rains brought temporary relief to the drought area in northeast Texas, but it was not enough to compensate for the significant deficits of the last 11 months.
The February precipitation pattern at the primary stations in Alaska was mixed. Across Hawaii, the precipitation pattern was also mixed. In Puerto Rico, the month was predominantly dry, based on National Weather Service radar estimates of precipitation. February streamflow averaged near normal for Puerto Rico and the Hawaiian Islands.
The February dryness aggravated long-term drought in the Southwest and Great Plains (3 to 6 to 9 to 12 months). Long-term moisture deficits persisted across parts of the mid-Mississippi Valley (last 9 to 12 months) and West into the northern High Plains and central Plains (last 48 to 60 months).
Some regional highlights:
- Several states had the tenth driest, or drier, month in February and also for multi-month seasons (December-February, September-February, March-February and others). These states include:
- Record dry conditions were reported at several stations in Arizona, New Mexico, Texas, and West Virginia. At the end of February, Phoenix, AZ had no precipitation for 133 consecutive days, making November 2005-February 2006 the driest November-February on record. With just 0.14 inch of precipitation since November 1, Albuquerque, NM had the driest November-February since at least 1893.
- Numerous wildfires during the month burned across several states in the central and southern Plains, southern Appalachians, and adjoining parts of the Tennessee and Ohio valleys. The fires were especially widespread during the end of February into the beginning of March.
- In central Texas, managers at the Edwards aquifer imposed a drought alarm, asking users who draw their water from the aquifer to lower their water consumption by 20 percent. As of February 12, drought conditions, statewide, have created an estimated $1.5 billion in losses. In Arizona, the Commission on Emergency Management declared a drought warning for the Navajo Nation. By the end of the month, in parts of Illinois farm ponds and wells had gone dry and numerous grass fires had developed. The Missouri Drought Assessment Committee declared 81 of the state's counties in some form of drought status, ranging from drought advisory to Phase 3 "conservation phase" drought.
- More than two-thirds of the winter wheat crop in Texas and Oklahoma was rated poor to very poor by early March. The winter wheat crop was also suffering in other states in the Plains, Midwest, and East.
- End-of-month and month-averaged soil moisture conditions, based on model computations (CPC-1, CPC-2, MRCC), were drier than normal across a broad swath from the southern Plains to the central Plains and western Great Lakes. From this core area, dry soil moisture conditions extended into the southwestern and east central U.S. The models also indicated dry soil moisture conditions in parts of Alaska and Hawaii, and near the surface and at depth from Nebraska and Kansas to the Lower Great Lakes and Ohio Valley.
- Streamflow levels reflected the February precipitation pattern. February streamflows were below seasonal norms across much of the Great Plains and mid-Atlantic region, the mid-Mississippi Valley, the southern and central Appalachians and adjoining Ohio and Tennessee valleys, and Southwest, as computed by models and based on USGS observations.
- Worsening drought conditions in the Southwest increased the western U.S. drought percentages (PDI December, January, February). About 21 percent of the western U.S. (Rockies westward) fell in the moderate to extreme drought category (as defined by the Palmer Drought Index) as of the end of February. Aggregated reservoir levels in the West (provided by the USDA) reflected the long-term precipitation deficits in many states.
