The United States must maintain existing long-term stations within the National Climatic Data Center (NCDC) cooperative network, particularly the subset of those stations that make up the Historical Climate Network.

The National Center for Environmental Prediction has recently started to archive a merged WSR88-D (Doppler radar)/gauge product (4-km resolution) that covers most of the United States. The suitability of these data for climatological purposes needs to be evaluated, and steps must be taken to ensure the security of the long-term archive of these data and that they are freely available to the scientific community.

Only a very small number of stations now operate in the continental United States that collect a full suite of surface radiation observations (the SURFRAD network). The adequacy of this network for studies of seasonal to interannual variability should be evaluated.

Snow water equivalent point observations are collected primarily at Natural Resources Conservation Service Snow Telemetry sites in mountainous areas of the western United States. The suitability of these sites for long-term climate studies needs to be evaluated (the longest records from these stations date only to the mid-1980s). Snow depth measurements are collected at some NCDC cooperative stations. The feasibility of using some subset of these stations to measure snow water equivalent should be evaluated. The object is to achieve a much more uniform spatial distribution of station-based observations.

NOAA's National Operational Hydrologic Remote Sensing Center and its National Environmental Satellite, Data, and Information Service (among other entities) produce satellite-based snow areal extent measurements of the conti-