TITLE: Mesonet Arizona Maricopa County ALERT Weather Station Network Data CONTACTS: Flood Control District of Maricopa County sdw@mail.maricopa.gov (602) 506-8701 http://www.fcd.maricopa.gov/alert/alert.htm 1.0 DATA SET OVERVIEW This data set contains surface meteorological data from the Maricopa County ALERT weather station network. There are a total of 29 stations included in the data set. The parameters collected and temporal resolution vary by station. The stations are located throughout Maricopa County in Arizona. This data set covers the period from 1 June to 30 September 2004. The data are in columnar ASCII format. 2.0 INSTRUMENT DESCRIPTION 2.1 Instrumentation Information At the time of this writing (25 March 2005) instrumentation information is not available. It is expected that by April or May of 2005 the Maricopa County Flood Control District web page: http://www.fcd.maricopa.gov/alert/alert.htm will have detailed information on the instrumentation at each station. Also included will be site descriptions, obstructions and photographs around each station. 2.2 Station Locations Station locations are included in the comma delimited file weather_sites.txt that is included with your data order. 3.0 DATA COLLECTION AND PROCESSING Information on the collection and processing of these data can be found at the Maricopa County network page: http://www.fcd.maricopa.gov/Services/ALERT/default.asp UCAR/JOSS conducted no processing or quality control on these data. 3.1 Wind Processing From the Maricopa County web page: Q: Why do the "Wind Speed" sensors appear to read so low? A: Sensors of the "Wind Speed" type do not transmit the instantaneous wind velocity but rather an average wind speed over a time period. That period happens to be the time it took for the last 1 km of wind (wind run) to "blow" past the sensor, so the period is shortened as the wind speed increases. The average wind speed reported is the distance (1 km) divided by the time (seconds), converted to miles per hour. 4.0 DATA FORMAT AND FILE NAMING 4.1 Data Format There are individual files for each station and parameter. These data are in columnar ASCII format. Each file contains some header records, e.g. FCDMC ALERT System Data Display 5143 Tiger Wash Fan Solar Radiation Date Time watts/sqm These provide the sensor id (5143) the station name (Tiger Wash Fan), the parameter (Solar Radiation) and then the data column headers with the Date and Time (in Mountain Standard Time) and the units (W/m2 in this case). 4.2 File Naming conventions StationName_SensorID_Parameter.txt e.g. TigerWashFan_5143_solarradiation.txt 5.0 DATA REMARKS None. 6.0 REFERNCES None.