Descriptions of networks that appear in TahoeClim are listed in alphabetic order below.
Airports (ASOS and AWOS)
Airports and a few other locations have long taken hourly data via manual means. Starting in the mid-1990s a system of automated measurements was emplaced, numbering close to 1000 sites in the US. The Automated Surface Observing System (ASOS) is generally run by the National Weather Service, and a counterpart Automated Weather Observing System (AWOS) is managed by the Federal Aviation Administration (FAA). These sites are often referred to by their ICAO identifier (International Civil Aviation Organization), the four letter abbreviation used by aviation (KRNO for Reno, KTRK for Truckee, KTVL for South Lake Tahoe, KBLU for Blue Canyon, etc), or by other designators such as a 5 or 6-digit World Meteorological Organization (WMO) or older WBAN (Weather Bureau Army Navy) five digit numbers, as well. These data generally include aspirated temperature, wind speed, wind direction, relative humidity, dewpoint temperature, wet bulb temperature, barometric pressure, and precipitation, visibility and ceiling. Measurements are made hourly, and more frequently as conditions change. ASOS and AWOS stations may be co-located with COOP stations. Stations in the ICAO network generally have long-running and complete records. Data have been obtained from NCDC and through live ingest and are available at WRCC. For more information, please visit the NOAA ASOS page.
California and Nevada Climate Trackers
The California and Nevada Climate Trackers account for effects of complex topography on climate in different regions of California/Nevada. The climate trackers use gridded data from PRISM, updated with Coop data, to access and summarized statewide monthly climate data. Primary variables considered are average monthly mean, maximum, an d minimum temperatures, and monthly precipitation totals. More information on California Climate Tracker. More information on Nevada Climate Tracker.
The California and NevadaSmoke and Air Committee (CANSAC) uses the Penn State/NCAR Mesoscale Model 5 to create twice daily meteorological forecasts at a resolution of 4 km. Parameters include surface wind speed, relative humidity, accumulated precipitation, and temperature. The products are primarily for the participating agencies and for the research community interested in atmospheric and meteorological applications pertaining to fire weather, smoke dispersion/transport, fire danger and fire behavior. These data consist of gridded values of principal meteorological elements for the Lake Tahoe domain such as surface wind speed, Some of the goals and functions of the CANSAC real-time forecasting system are:
The California Air Resources Board (CARB) gathers air quality (AQ) data for the State of California, ensures the quality of the data, designs and implements air models, and sets ambient air quality standards for the state. CARB sites in TahoeClim collect ozone, temperature, wind speed, and barometric pressure at Echo Summit, and BAM PM10, temperature, and wind speed at Sandy Way. For more information, visit CARB homepage.
CA Snow Survey
Stations labeled as "CA Snow Survey" are ingested from the California Data Exchange Center (CDEC), operating under the auspices of the California Department of Water Resources (CDWR). Many of these stations are operated and managed by CDWR or by regional and local public and private cooperators as part of the California Cooperative Snow Survey. Of particular interest is the CDWR network of automated snow/precipitation reporting gages (some of these record temperature, wind, and humidity as well), and most report by satellite once an hour. The data are used for flood and water supply forecasts, as well as scheduling hydroelectric reservoir releases. Most stations transmit data near-real time. Few quality checks are performed on this data. Most of these sites have records of 2-4 decades in length. For more information, visit California Data Exchange Center
Climate Summary Maps (HPRCC/WRCC)
The current climate summary maps are produced daily using data from the Applied Climate Information System (ACIS) managed by the Regional Climate Center Program. Stations used are from the National Weather Service Cooperative Observer Network (COOP), supplemented in some areas by local and regional data (not in the Tahoe area). Departures from normal refer to the 1971-2000 period at present, but this will soon change to 1981-2010. The maps available include precipitation total, precipitation departure from normal, and precipitation percentage of normal, average temperature, temperature departure from normal, heating degree days, and cooling degree days. For more information, visit WRCC or HPRCC.
The National Weather Service (NWS, an agency within the National Oceanic and Atmospheric Administration, NOAA) maintains a network of manual sites operated by volunteers. Daily summary data from many of these sites extend for decades to a century or more. The five main elements recorded by most stations include maximum and minimum temperature, precipitation, snowfall, and snow depth. Some stations record daily evaporation and soil measurements as well. Automatic observing stations are considered cooperative stations if their observed data are used for services which otherwise would be provided by cooperative observers. A cooperative station may be collocated with other types of observing stations such as standard airport observations stations, FAA Flight Service Stations, etc. In these cases, that portion of the station observing program supporting the cooperative program's mission is treated and documented independently of the other observational and service programs. Though most cooperative observers are volunteers, some are paid where specific types of services are needed. Observers transmit data for quality control and archive at the National Climatic Data Center (NCDC), by paper and mail, email, or computer. A recent and ongoing change is under way to obtain these data via manual web entry through a process known as Weather Coder III. The network is slated to become essentially paperless in 2012. Observers record temperature and precipitation daily and send those reports monthly to the National Climatic Data Center (NCDC) or an NWS office. Many cooperative observers provide additional hydrological or meteorological data, such as evaporation. Equipment used at NWS cooperative stations may be owned by the NWS, the observer, or by a company or other government agency, as long as it meets NWS equipment standards. For more information, please visit NWS Cooperative Observer Program page.
DRI (Desert Research Institute)
Stations labeled as "DRI" are automated stations either installed or maintained by DRI for various projects and sponsors, about 150 in total, with automated ingest of data at the Western Regional Climate Center. Stations typically record observations at hourly or 10-minute intervals, with measurements that usually include at least: air temperature, relatively humidity, wind speed and direction, solar radiation, and often precipitation and soil temperatures.
NASA-JPL Buoy Network
The Lake Tahoe website at the Jet Propulsion Laboratory was established to act as portal to the data and results from collaborative experiments underway at Lake Tahoe between the University of California, Davis and JPL. The site provides access to some of the near real time data acquired from a set of continuous monitoring stations established by JPL-UCD in 1999. Measurements are made from 4 permanently moored buoys referred to as TB1, TB2, TB3, TB4, and the US Coast Guard station on the northwest shore. Parameters measured include longwave and shortwave radiation, net radiation, wind speed, wind direction, barometric pressure, air temperature, relative humidity, aerosol optical depth, total column water vapor, temperature from radiometer, skin temperature.For more information, please visit NASA Lake Tahoe Validation page.
The Nevada Department of Transportation maintains a network of roadside meteorological instruments on Nevada roadways. The data from these instruments is published, archived and maintained through the Road Weather Information System (RWIS) interface. NDOT sensors measure wind speed, direction, and gust, relative humidity, air temperature, dew point, rainfall, and rain rate. The data are published automatically on RWIS and cannot be guaranteed as to accuracy or timeliness. For more information, please visit NDOT Road Weather Information System page.
North American Freezing Level Tracker
This analysis tool allows one to track through time the height of the freezing level (0 C or 32 F) above sea level. Other temperature thresholds are available as well. The mean daily temperature used for this profile is formed from the four six-hour averages available from the NCEP/NCAR Global Reanalysis from January 1948 until the last few days. The grid spacing is approximately 2.5 x 2.5 degrees of latitude/longitude. For more information, please visit NAFLT page.
The Remote Automated Weather Station (RAWS) network is an interagency effort coordinated out of the National Interagency Fire Center. The original purpose of this network was in support of fire, but that has enlarged through time to many other aspects of resource management and of agency operations. RAWS stations record data every hour and are transmitted by satellite. Most stations record wind speed and direction, peak gust, air temperature, relative humidity, fuel temperature, relative humidity, precipitation, and solar radiation. Data extend from the mid 1980s (earliest stations started in 1983). The network now consists of about 2000 stations. These stations are owned and operated by various agencies, including Bureau of Land Management (BLM) and the US Forest Service, National Park Service, Fish and Wildlife Service, Bureau of Indian Affairs, and state and federal agencies. RAWS stations provide data for a variety of projects such as monitoring air quality, rating fire danger, and providing information for research applications. RAWS data available on TahoeClim is provided through the Western Regional Climate Center, who is the official archive of the RAWS data. For more information, please visit WRCC RAWS page.
Reno-Carson is an unofficial, unedited network of volunteer observers in the Reno/Carson/Tahoe region. Sensors in this network collect temperature, precipitation, and snowfall data. Data are maintained by WRCC. For more information, please visit Reno-Carson Network.
The Natural Resources Conservation Service (NRCS), an agency of the US Department of Agriculture, installs, operates, and maintains an extensive automated system to collect snowpack and related climatic data in the western United States, including Alaska, called SNOTEL (for SNOwpack TELemetry). Basic SNOTEL sites have a pressure sensing snow pillow, storage precipitation gage, and air temperature sensor. However, they can accommodate 64 channels of data and will accept analog, parallel, or serial digital sensors. On-site microprocessors provide functions such as computing daily maximum, minimum, and average temperature information. Generally, sensor data are recorded as a grab sample every 15 minutes and reported out in a daily poll of all sites. Special polls are conducted more frequently in response to specific needs. The earliest SNOTEL measurements generally date from around 1980 plus or minus a year or two. The SNOTEL measurements are an automated replacement from a western manual system of snow courses that extend from as early as the 1920s. The basic mandate of SNOTEL is to support predications of water supplies, which are largely driven by snowmelt. With time, climate studies, air and water quality investigations, and resource management concerns are increasingly served by the SNOTEL network. The high-elevation watershed locations and the broad coverage of the network provide important data collection opportunities to researchers, water managers, and emergency managers for natural disasters such as floods. For more informaton, please visit NRCS SNOTEL page.
A snow course is a permanent site that represents snowpack conditions at a given elevation in a given area. Measurements consist of a series of ten manually obtained samples of snow water content obtained with a Mt Rose Snow Sampler or Federal Snow Sampler. A hollow aluminum tube with a cutting edge is drilled into the snow pack until the surface is encountered. The tube is then weighed and the aluminum weight subtracted to obtained the weight of the frozen water in the tube. A depth measurement is also made. Generally, snow courses are about 1,000 feet long and are situated in small meadows protected from the wind. Many but not all snow courses have been converted to automated SNOTEL sites. Snow course records extend from as early as the 1920s and 1930s, and many still exist after widespread conversion to SNOTEL in the 1980s and 1990s. For more information, explore how manual snow surveys are conducted and how to interpret snow course data.
UC Davis TERC REMOTE Network
Tahoe Environmental Research Center (TERC)operates a network of 6 meteorological stations on land but immediately adjacent to the lake in the watershed surrounding Lake Tahoe. These stations measure wind speed, wind direction, wind gust, temperature, barometric pressure, solar radiation, precipitation, relative humidity, and water temperature. For each station, the user can make various graphs and perform analyses of available data. Data from these stations are used in investigations of Lake Tahoe circulation, clarity loss, air quality, and other environmental changes. For more information, visit the Tahoe Environmental Research Center or the UC Davis REMOTE Lake Tahoe page.
Since 1889, the US Geological Survey has collected continuous discharge and other time series data on the nation’s rivers and streams. TahoeClim links to the USGS Waterwatch site, which displays maps, tables, and graphs of real-time, recent, and historic stream flow conditions and stream stage (water elevation). The Tahoe City location reports the official lake level for Lake Tahoe. More information can also be found at USGS Waterwatch.
WestMap is the Western Climate Mapping Initiative, a collaborative effort between the University of Arizona, WRCC, and the Oregon State University PRISM group. The initial fundamental data consist of monthly PRISM temperature (maximum, mean, minimum) and precipitation at 4km resolution. Period of record is 1895-present. Values are updated monthly. Currently, WestMap supports gridded PRISM climate data for the Western United States. The interface has been designed to allow expansion of this domain to the continental United States in the future. WestMap users can access user-specified data, and use this data to create maps and time series plots. The digital climate maps accessible on the WestMap site are created using PRISM (Parameter-elevation Regressions on Independent Slopes Model) an analytical tool that uses point data, a digital elevation model, and other spatial data sets to generate fine scale grid-based estimates of monthly, yearly, and event-based climatic parameters, such as precipitation, temperature, and dew point. PRISM makes use of an integrated set of rules, decision-making, and calculations designed to imitate the process an expert climatologist would go through when mapping climate data. For more information, please visit Westmap.