Some Stations have evaporation equipment to document moisture evaporation data used in both hydrology and agriculture. Evaporation pan and associated equipment. Many observers take river and stream level reading to support the NWS hydrology forecast and warning programs. At official NWS Cooperative Weather Stations observations are taken from instrumentation provided and maintained by the National Weather Service. Observations are taken at least once a day.
Some stations provide data more often than others.
Observations are recorded from instrument readings obtained at predetermined times to form a consistent weather picture that has occurred in the local area for a specific period, usually 24 hours. The Cooperative Weather Observer's data are also becoming more critical to operational decision made at the NWS office. With this fact in mind, the NWS is now in the midst of a program of near real time data acquisition known as Remote Observation System Automation or ROSA . When fully implemented, all data elements from Cooperative Weather Stations throughout the Nation will be electronically transmitted directly to the NWS where data will be ingested into forecasting models after appropriate quality control is applied to these data.