Unregistered User Registration Sample Daily Report Sample Monthly Report Registered User Logon Hourly Daily Daily ETo Variance Monthly Monthly Average ETo Quality Control QC Overview Current Flag Summary Current Hourly Flags Current Daily Flags Former Flag Summary Former Hourly Flags Former Daily Flags More Info Station List Data Types Data Formats Data Size		Current Hourly Flags Following is a short description of the hourly flags currently in use. Also included are descriptions for the flags and the criteria used to test data quality. It should be noted that the same flag can mean different things for different weather parameters. 1. Hourly Solar Radiation Solar radiation data is flagged based on hourly extraterrestrial radiation. Flag Description R The sun is more than 10 degrees above the horizon and the ratio of measured hourly solar radiation to calculated extraterrestrial radiation is equal to or greater than 1.0. The sun is more than 10 degrees above the horizon and the measured hourly solar radiation is equal to or less than 0 Wm-2. The sun is less than 10 degrees above the horizon and the absolute value of measured hourly solar radiation is equal to or greater than 10.00 Wm-2. S Measured hourly solar radiation is less than or equal to -50.00 Wm-2 or is equal to or greater than 4,000 Wm-2. Daylight and solar radiation is constant for 4 hours in a row. Y The sun is more than 10 degrees above the horizon and the ratio of measured hourly solar radiation to calculated extraterrestrial radiation is greater than 0.85. The sun is less than 10 degrees above the horizon and the absolute value of measured hourly radiation is equal to or greater than 6.00 Wm-2. 2. Hourly Net Radiation Hourly net radiation quality test is based on theoretical extremes, measured solar radiation, vapor pressure and air temperature. Flag Description N Net radiation is not calculated for station. Q Solar radiation is severe - flagged S. Two or all three sensors (solar radiation, vapor pressure and air temperature) are missing. R Net radiation is less than -100, or equal to or greater than 800. Solar radiation, air temperature or vapor pressure is flagged R. S Solar radiation, air temperature or vapor pressure is severe. Net radiation is equal to or greater than to 4,000 Wm-2. 3. Hourly Soil Temperature Flag Description R Soil temperature is far out of historical range (outside the 99.8% confidence interval). Y Soil temperature is moderately out of historical range (outside the 96% confidence interval). Soil temperature drop or rise between this hour and the previous hour is greater than 3 C, or 5.4 F. 4. Hourly Air Temperature Flag Description R Air temperature drop or rise between this hour and the previous hour is greater than 10 C, or 18 F. Air temperature is far out of historical range (outside the 99.8% confidence interval). S Air temperature is constant for 4 hours in a row. Y Air temperature is moderately out of historical range (outside the 96% confidence interval). 5. Hourly Vapor Pressure Flag Description Q Air temperature or precipitation is severe (either or both are flagged S). R Vapor pressure is constant for 4 hours in a row. Actual vapor pressure is equal to or less than to 0.00 kPa or actual vapor pressure is greater than 1.05 times the saturation vapor pressure. S Vapor pressure is equal to or less than 0. Y Relative humidity is less than 50 percent during an hour with 1.00 mm or more of precipitation. 6. Hourly Wind Speed Flag Description I Wind speed is equal to or less than 0.447 (1 mph) or wind speed is constant for four hours in a row. S Wind speed is equal to or less than 0. Wind speed is equal to or greater than 45 meters per second or 100 mph. 7. Hourly Resultant Wind Flag Description I Wind speed is flagged I. Q Wind speed is severe. R Resultant wind is equal to or greater than wind speed. 8. Hourly Wind Direction Flag Description S Wind direction is less than 0 or greater than 360 degrees. R Wind direction is constant for four hours in a row. 9. Hourly Standard Deviation of Wind Direction Flag Description S Wind direction is severe. Standard deviation of wind direction is between 188 and 189. R Wind direction is R. Standard deviation of wind speed is equal to or greater than 180 degrees or less than 0. 10. Hourly Precipitation Precipitation data quality test is based on extreme values and daytime cloud conditions inferred from the relationship between solar radiation and extraterrestrial radiation. Flag Description R Precipitation is more than 100 mm (4 inches). Measured solar radiation is greater than 75 percent of calculated extraterrestrial radiation, the sun is 10 or more degrees above the horizon, and the station shows recorded precipitation (precipitation is greater than 0). S Precipitation is less than 0. Y Measured solar radiation is greater than 65 percent of calculated extraterrestrial radiation, the sun is 10 or more degrees above the horizon and the station shows recorded precipitation. 11. Hourly Evapotranspiration ETo quality test is based on net radiation, wind speed, air temperature and vapor pressure. Flag Description R One or more of the above listed measurements is flagged R. Wind speed is flagged I. S Precipitation is less than 0. Y One or more of the above listed measurements is flagged Y. 12. Hourly Relative Humidity Flag Description Q Air temperature or vapor pressure is severe. R Air temperature or vapor pressure is R. Y Air temperature or vapor pressure is Y. 13. Dew Point Temperature Flag Description Q Relative humidity is Q. R Relative humidity is R. Y Relative humidity is Y. If you have questions, please contact the following: Bekele Temesgen Department of Water Resources Office of Water Use Efficiency P.O. Box 942836 Sacramento, CA 94236-0001 temesgen@water.ca.gov Simon Eching Department of Water Resources Office of Water Use Efficiency P.O. Box 942836 Sacramento, CA 94236-0001 seching@water.ca.gov
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