The PRISM SNOTEL QC system applies quality control measures to SNOTEL data, produces quality flags, and estimates replacement values for missing or suspicious observations. QC measures include general range checks, station profile range checks, spatial QC, and multi-sensor QC. The system is active for all SNOTEL stations, and most SNOLITE stations, within the western conterminous US.

For SNOTEL stations, QC'ed elements include daily minimum and maximum temperature, precipitation, and snow water equivalent. Snow depth has also been included as an ancillary variable. For most SNOLITE stations, QC'ed elements are limited to daily minimum and maximum temperature. Each day, the PRISM SNOTEL system runs a series of four analyses, in this order: single-station QC, profile QC, spatial QC, multi-sensor QC.

"First look" QC results, based on original data, are typically available within 36 hours of the end of a measurement day. The results are updated approximately 5 days later, based on the data current at that time. Similar updates occur after intervals of 1, 2, 3, 4, 5, and 6 months; therefore, results are not considered final until the 6-month update has been made.

Please note that PRISM SNOTEL QC results are not intended to preclude edits made by NRCS Data Collection Offices.

• Read an overview description of the QC system
• View/download detailed documentation for the QC system
• Download QC data from SNOTEL and SNOLITE stations for specific dates
• Set up bulk downloads of QC data
   
• Access the QC mapping interface