Droughts

A drought is a period of drier-than-normal conditions that results in water-related problems. Precipitation (either rain or snow) falls in uneven patterns across the country. The amount of precipitation at a particular location varies from year to year,...
The beginning of a drought is difficult to determine. Several weeks, months, or even years may pass before people know that a drought is occurring. The end of a drought can occur as gradually as it began. Dry periods can last for 10 years or more. During...
A period of below-normal rainfall does not necessarily result in drought conditions. Some rain returns to the air as water vapor when water evaporates from water surfaces and from moist soil. Plant roots draw some of the moisture from the soil and return...
To view the USGS streamflow information on drought go to Drought Watch. This map shows below normal 7-day average streamflow compared to historical streamflow for the day of the year (United States). 
Rainfall in any form will provide some drought relief. A good analogy might be how medicine and illness relate to each other. A single dose of medicine can alleviate symptoms of illness, but it usually takes a sustained program of medication to cure an...
Water levels in wells are constantly changing both in the short term and over the long term. Some wells even have a seasonal change. In the short term, water levels can be lowered just by pumping water out of the well for use. Also, a well may be pumped...
The Palmer Drought Severity Index was developed by Wayne Palmer of the U.S. Weather Bureau (now the National Weather Service) in the 1960's and uses temperature and rainfall information in a formula to determine dryness. It has become the semi-official...