ENCAMPMENT - So what does it mean to be in an exceptional, extreme, severe or moderate drought?

According to State Climatologist Jan Curtis, the labeling is an inexact science, but one that incorporates reservoir levels, soil moisture, precipitation levels and snowpack.

The Palmer Drought Index is one tool used to determine drought, and numbers are attached to severity. The index is used by the U.S. Drought Monitor.

A negative five or less classifies an area as "exceptional," meaning "exceptional and widespread crop/pasture losses; exceptional fire risk; shortages of water in reservoirs, streams and wells creating water emergencies."

The Palmer Index was designed in 1965 to standardize drought classification across the country. It takes into account weather conditions and soil moisture over time.

Soil moisture is a key indicator and can have the biggest effect on farmers and ranchers. Even with rains, soil moisture can remain low, as heavy rains falling in a short amount of time don't sink into the soil and in fact end up washing away valuable topsoil.

The state has one soil moisture sensor in Torrington. It is placed at two, eight, 20 and 40 inches into the ground. The sensor measures the resistance of electricity shot through the soil. If there is more water, the resistance is less, because water conducts electricity.

Curtis said the state is working on getting more soil moisture sensors for around the state. He said there is a national initiative to integrate various weather and hydrologic sampling stations around the country to better monitor drought.

"We'd like to have at least one significant weather station every 20 square miles in our state and in fact across the country," he said. "We can work together to determine the severity of drought and dole out help."

Environmental reporter Whitney Royster can be reached at (307) 734-0260 or at royster@mail.trib.com.