- Network weaknesses:
o RAWS network is focused largely on fire management needs (formerly focused only on fire needs).
o Frozen precipitation is not measured reliably.
o Station operation is not always continuous.
o Data transmission is completed via one-way telemetry. Data are therefore recoverable either in real-time or not at all.
The RAWS network is used by many land-management agencies, such as the BLM, NPS, Fish and Wildlife Service, Bureau of Indian Affairs, Forest Service, and other agencies. The RAWS network was one of the first automated weather station networks to be installed in the U.S. Most gauges do not have heaters, so hydrologic measurements are of little value when temperatures dip below freezing or reach freezing after frozen precipitation events. There are approximately 1100 real-time sites in this network and about 1800 historic sites (some are decommissioned or moved). The sites can transmit data all winter but may be in deep snow in some locations. The WRCC is the archive for this network and receives station data and metadata through a special connection to the National Interagency Fire Center in Boise, Idaho.
G.16. NWS/FAA Surface Airways Observation Network (SAO)
- Purpose of network: provide near-real-time (hourly or near hourly) measurements of meteorological variables and are used both for airport operations and weather forecasting.
- Primary management agency: NOAA, FAA.
- Data website: data are available from state climate offices, RCCs (e.g., WRCC,http://www.wrcc.dri.edu), and NCDC (http://www.ncdc.noaa.gov).
- Measured weather/climate elements:
o Air temperature.
o Dew point and/or relative humidity.
o Wind speed.
o Wind direction.
o Wind gust.
o Gust direction.
o Barometric pressure.
o Precipitation (not at many FAA sites).
o Sky cover.
o Ceiling (cloud height).
o Visibility.
- Sampling frequency: element-dependent.
- Reporting frequency: element-dependent.
- Estimated station cost: $100000–$200000, with maintenance costs approximately $10000/year.
- Network strengths:
o Records generally extend over several decades.
o Consistent maintenance and station operations.
o Data record is reasonably complete and usually high quality.
o Hourly or sub-hourly data.
- Network weaknesses:
o Nearly all sites are located at airports.
o Data quality can be related to size of airport—smaller airports tend to have poorer datasets.
o Influences from urbanization and other land-use changes.
These stations are managed by NOAA, U. S. Navy, U. S. Air Force, and FAA. These stations are located generally at major airports and military bases. The FAA stations often do not record precipitation, or they may provide precipitation records of reduced quality. Automated stations are typically ASOSs for the NWS or AWOSs for the FAA. Some sites only report episodically with observers paid per observation.
