USDA/NRCS/NWCC SNOTEL Daily Data, Text Reports (DSI-6430)Entry ID: gov.noaa.ncdc.C00392
Abstract: USDA/NRCS/NWCC SNOTEL Daily Data, Text Reports is digital data set DSI-6430, archived at the National Climatic Data Center (NCDC). The SNOTEL data collection network, operated by the National Water and Climate Center of the Natural Resources Conservation Service, of the US Department of Agriculture (USDA/NRCS/NWCC) since the mid-1970s, was established to support water supply assessment and ... forecast responsibilities of the NRCS. Approximately 75% of the water needs of the western USA are supplied from the annual melt water of mountain snow packs. Monitoring the accumulation and depletion of the snow pack in this region is critical for stream flow and reservoir management and for all users of the regions water supply. The growing SNOTEL (SNOwpack TELemetry) data collection is also becoming more valuable for the study of climate and climate change, providing daily data from previously unavailable remote alpine regions. The system evolved from a Congressional mandate in the mid-1930s for NRCS to measure snowpack in the mountains of the West and forecast the water supply. The programs began with manual measurements of snow courses; since 1980, SNOTEL has reliably and efficiently collected the data needed to produce water supply forecasts and to support the resource management activities of NRCS and others. The SNOTEL network currently consists of about 600 remote sites that are equipped with automated instruments. The sites are in 12 western states: Alaska, Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming. Data from most stations begins in October 1978, except October 1965 for a small number of Alaskan stations. Data are collected continually (normally every 15 minutes, sometimes more frequently) and transmitted by microburst technology 1 to 4 times per day to master receiving stations, and then on to the NWCC data processing office in Portland, Oregon. Data in DSI-6430 are a once-daily resolution, taken from the midnight observation, that has received some quality control from NRCS Data Collection Offices. Daily water equivalent of snow is measured by the weight of the snow pack on a snow pillow, a fluid-filled plastic or steel flat pouch with hydraulic connections to a manometer, or pressure measuring device. Manometer pressures are converted to inches of precipitation values. Air temperatures are measured by thermistors in NRCS-designed housings. The standard height of the sensor above ground level (AGL) is in debate at present, with some sensors installed at 20 ft AGL, and others at 1 m above the maximum snow pack. Daily accumulated precipitation is measured by the weight of the accumulated precipitation in a storage rain gauge equipped, like the snow pillow, with hydraulic connections to a manometer. The storage rain gauges are emptied and recharged annually and contain antifreeze to prevent freezing, and oil to prevent evaporation of accumulated precipitation. Storage rain gauges in severe alpine winter conditions will sometimes experience a total snow blockage of the orifice. When this occurs, the storage gauge precipitation values will show no accumulation during incidents of snow pillow accumulation gains, followed by a sudden jump in storage gauge values when the snow cap collapses into the gauge. SNOTEL data includes metadata about the station. Major data parameters include water equivalent of snow in inches (snow pillow); maximum, minimum, and average temperatures for the previous calendar day in degrees Celsius; and accumulated precipitation, on a water year basis, in inches. Not all stations report all of these parameters.
Purpose: To make a wide range of climatic data available to researchers and the public.
SUPPLEMENTAL INFORMATION: data set
CURRENTNESS REFERENCE: Ground Condition
Data Set Citation
Dataset Originator/Creator: National Climatic Data Center, NESDIS, NOAA, U.S. Department of Commerce
Dataset Title: USDA/NRCS/NWCC SNOTEL Daily Data, Text Reports (DSI-6430)
Dataset Release Date: Unknown
Data Presentation Form: tabular digital dataOnline Resource: http://www.ncdc.noaa.gov
Start Date: 1965-10-01
Temporal Resolution: Daily
Temporal Resolution Range: Daily - < Weekly
ISO Topic Category
Quality ATTRIBUTE ACCURACY REPORT: Not provided
LOGICAL CONSISTENCY REPORT: Unknown
COMPLETENESS REPORT: Completeness information not available.
PROCESS DESCRIPTION: Unknown
PROCESS DATE: Unknown
Access Constraints ACCESS CONSTRAINTS: None
DISTRIBUTION LIABILITY: Every effort has been made to ensure that these data are accurate and reliable within the limits of current NOAA quality control procedures. NOAA can only certify that the data provided to its customers is an authentic copy of the records which were accepted for inclusion in NOAA archives. NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.
Use Constraints None
Data Set Progress
Role: DIF AUTHOR
Email: ncdc.orders at noaa.gov
151 Patton Avenue, Room 120
Province or State: NC
Postal Code: 28801-5001
Creation and Review Dates
DIF Creation Date: 2006-06-27
Last DIF Revision Date: 2011-07-21