is operated through the cooperation of the
Park Service and the US Geological
is managed by the Tucson Field Office of the USGS,
AZ Water Science Center.
Precipitation data from this site are considered
'Temporary' and will NOT be available for retrieval
for dates prior to the 120-day display period.
Although the precipitation gauge is generally calibrated at
least once per year, the 'temporary' classification
means that documented routine inspections and other quality
assurance and quality control measures may not have been
performed that would make the data acceptable for publication
according to USGS policy. This message is not meant to convey
that the precipitation data are bad data, but only that not
all the steps were taken to make the data publishable.
Inquiries may be made for data prior to the most recent 120
days by selecting the link "Questions about
sites/data?" at the bottom of this webpage.
Why do we collect precipitation
data? The precipitation data are collected for
2 primary reasons: 1. The National Weather Service (NWS) uses the data to
help calibrate their radar-based precipitation data to report
more accurate rainfall. This, in turn, gives the NWS more
accurate information for projecting flooding in and around
communities. With this information NWS can more confidently
issue flood alerts/warnings in these areas to prepare the
public and local autorities. 2. The precipitation data are also used by the USGS to
get forewarning of upcoming elevated flow events at their
streamflow stations. These forewarnings give the USGS extra
time to deploy staff out to collect physical discharge
measurements at stations where measurements of flow are
needed to calibrate the station. Measurements during high
flow conditions are often rare and hard to acquire due to the
fast, flashy nature of many streams in Arizona. The
measurements are then used to calibrate the station for
reporting more accurate streamflow.
(Site data are transmitted
& updated hourly)
This station managed by the Tucson Field Office; USGS AZ-WSC.