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Time series precipitation data will NOT be
available for retrieval prior to the 120-day display
period. Although the instrumentation is generally
calibrated once/year, the temporary classification means that
documented routine inspections and other quality assurance
measures may not be performed that would make the data
acceptable for publication by USGS standards. This is not
meant to say that these data are not good data, but only that
these data are not guaranteed to be good quality
data. Inquiries may be made for data prior to the last 120
days by selecting the "Questions about
sites/data?" link at the bottom of this
webpage.
Why do we collect precipitation
data? The precipitation data are collected for
3 main reasons:
First, the National Weather Service (NWS) uses the
data to help calibrate their weather radar based
precipitation data to report more accurate rainfall.
Second, the rainfall totals at USGS rain-gages help
the NWS issue flood alerts/warnings to local government
agencies of projected flooding in or near downstream
communities.
Third, the data are used by the USGS to give them
forewarning of upcoming high flow events at their streamflow
gages. This forewarning allows USGS personnel time to deploy
a team to the gaging locations to obtain physical discharge
measurements of flow during high-flow conditions.
Measurements in high-flow conditions are often rare and hard
to acquire due to the fast, flashy nature of streams in most
of the drainages of Arizona. |
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