TITLE: Mesonet Arizona Maricopa County ALERT Precipitation 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 precipitation data from the Maricopa County 
ALERT precipitation network.  There are a total of 288 stations
included in the data set.  The data are collected on an event basis.
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
precip_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.


4.0  DATA FORMAT AND FILE NAMING


4.1  Data Format
 
There are individual files for each station.

These data are in columnar ASCII format. 

Each file contains some header records, e.g.

FCDMC ALERT System Data Display
5430 White Tank Peak
Precipitation Gage

Date       Time      inches

These provide the sensor id (5430) the station name (White Tank Peak),
the parameter (Precipitation Gage) and then the data column headers
with the Date and Time (in Mountain Standard Time) and the units
(inches).

Values are recorded on an event basis.

The precipitation values are cumulative over the water year.

4.2  File Naming conventions

StationName_SensorID.txt
e.g.
WhiteTankPeak_5430.txt

5.0  DATA REMARKS


Q: Why do most of the rain gages appear to read in increments of 0.04
inches?

A: Because most of the rain gages actually read in millimeters. One
millimeter is equal to 0.03937 inches, and it is this number that is used
by the computer to do calculations. For example, 7mm will read as 0.28
inches, but 8mm will round to 0.31 inches when reported in hundredths of
inches. A few of the raingages read in increments of 0.01 inches, and there
are no rounding errors in calculations for these gages.

6.0  REFERNCES


None.