Advancing Water Resources Research and Management

Symposium on Water Resources and the World Wide Web
Seattle, Washington, December 5-9, 1999

Hourly data, further information

Other hourly data are also available to the River Forecast Centers. For instance, the state of Oklahoma has a mesonet with one meteorological site per county, which the Tulsa RFC uses. Mesonet or local alert systems are used where available. At the West Gulf River Forecast Center, hourly reports are received from networks operated by the City of Dallas, Lower Colorado River Authority, San Jacinto River Authority, and the Harris County Flood Control. Local alert data (including hourly observations) at RFCs is collected by the nearest Weather Forecast Office either by direct line or dialup and is transmitted to the River Forecast Centers, in most cases with no QC (personal communication, Bob Corby). Some of these hourly data are summed over 24 hours (12 utc to 12 UTC) and subsequently transmitted as 24h totals to NCEP and thus find their way into the 24h station data stream. An example is BENM5 in Minnesota.

Concerning implications of the absence of quality control, at some sites observation problems are obvious and easily filtered out. For instance, Station STPM5 in St. Paul, MN, consistently provides continual rainfall with totals reaching well over 100 inches per day, every day. Other more subtle errors consist of persistent values of minimum but non zero precipitation at gages where it is highly unlikely that any precipitation is occurring. Western states such as Oregon show this tendency, especially at RAWS sites. Some sites appear to be susceptible to telemetering problems, since they report precipitation at regular intervals of a few to several hours that are clearly nonphysical. An example is AFRI1 on Aug. 22, 1999.

Many of these observation errors that find their way into the data stream are easily dealt with, and many of them are undoubtedly recognized by RFC forecasters and other local users. Some upstream (in a data sense) management of these data before they get into the telemetered data stream, or before they are disseminated from the Office of Hydrology, would be helpful.

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