Drought monitoring in Oklahoma: a collaborative endeavor

In 1995, the Oklahoma Climatological Survey began providing analyses of precipitation deficits to state decision-makers. A severe drought, which affected Oklahoma's wheat crop and cattle markets, in the Fall 1995 – Spring 1996 spurred the development of a State Drought Management Team, charged with formalizing Oklahoma's drought response policy. One of the foci of the Team was an emphasis on monitoring incipient drought conditions.

The Oklahoma Mesonet provides a vehicle for day-by-day monitoring of precipitation, soil moisture, and fire danger. Beginning with the 1995-1996 drought, Mesonet data have been combined with historical National Weather Service Cooperative Observer observations, to determine precipitation deficits at various scales, from one month to one year. The initial reports were distributed to key state decision-makers via facsimile on weekly intervals. Over the next two years, the process was automated and made available on the web.

During subsequent years, the drought monitoring decision-support tools have undergone several revisions, based on close collaboration with the Oklahoma Water Resources Board, the agency designated with monitoring drought conditions in the state, and the National Drought Mitigation Center. New indices, maps, time periods, and links have been added at the request of individual decision-makers. Prototypes were tested by these key user groups as new changes were implemented. Through these efforts, Oklahoma has become a national model for drought monitoring, embraced as an example of what other states should strive for by the Western Governors Association.

Recent additions to the Oklahoma Mesonet's instrument suite have enabled further information to be transmitted via the drought monitoring pages to decision-makers at the Water Resources Board. In 2002, the Mesonet commissioned a statewide network of soil moisture sensors. Current conditions are presented in the Fractional Water Index map on the main page, highlighting areas in which soils are beginning to show stresses. The most recent addition to the network has been several groundwater monitoring stations. Information from these sites is linked to the OCS drought monitoring pages as well.

Despite its successes in conveying real-time assessments of precipitation deficits and soil moisture conditions, the system lacks one key element: forecast information. In some regards, the system confirms what decision-makers already suspect, but what they really want to know is whether a drought will intensify or terminate. Efforts are underway to incorporate more climatological and forecast information, where possible, into the existing decision-making infrastructure. These efforts also will be detailed in the presentation.