Data

We only generate daily values if a day has a minimum of 88 15 min interval datapoints. The WISKI agent is ‘mean,min,max time weighted’. 

The sensors in the field for climate/weather data do not account for daylight savings, this will be one hour behind during Mountain Time (MT). All of the timeseries and discrete data is set to MT or Mountain Standard Time (MST).

These parameters originate from two different types of precipitation gauges.

• Tipping bucket rain gauge – Measures rainfall by counting the number of times a small bucket tips after collecting 0.005 inches of water. Tipping buckets do not measure snow accurately as snow may blow out of the funnel before melting and snowmelt may occur long after snowfall, causing delayed readings. Northern Water removes tipping bucket gauges from early October through early March to avoid snow‑related inaccuracies.
• Weighing bucket precipitation gauge – Measures precipitation by weighing the collected water (or snow). More accurate for snow and mixed precipitation.

The difference in Rain Total is measure by a tipping bucket rain gauge and the Difference in Precipitation is measured by a weighing bucket precipitation gauge. Tipping buckets do not measure snow accurately because snow that falls in the funnel can blow out before it melts and typically the snow will melt well after the snow has fallen. Northern Water removes the tipping bucket rain gauges from the beginning of October to the beginning of March. The tipping bucket mechanism will only tip when 0.005 inches of water drips through the funnel. 

Data from a weighing bucket inherently has some signal noise from the electronic sensor that literally weighs the precipitation that falls into or is collected in a bucket. Positive differences in weight indicate a precipitation event, negative differences can be from evaporation—hence an oil film is utilized to prevent such. However, slight negative differences can occur, particularly from wind that can slightly shake or vibrate the weighing bucket gauge. Daily differences use only two values—midnight at day start and midnight at day end. If either of these values were impacted by noise, false indications of slight precipitation or evaporation could result. Post processing can remove this signal noise but is not currently provided for the data sets on our website. Over long periods of time the weighing bucket noise tends to cancel out.

EOD values are stored in the following day. Ie) April 2 EOD would be reported at 00:00:00 on April 3. 

A Water Quality Site ID is a shorthand unique identifier for our water quality monitoring locations than can be used in place of a longer station name. These generally follow the syntax of two letter body of water code followed by a three or four letter identifier to indicate location or nearby landmarks. Example: Colorado River upstream of Shadow Mountain Reservoir is CR-SMU for Colorado River – Shadow Mountain upstream. 

The field with 1 a.m. is the Event level timestamp. This is manufactured with the 1 a.m. to allow for multiple samplings to group together in one result set. There is an additional field under the optional returnable fields, the “sample_timestamp” which gives the discrete date/time combo for each result.

The Sample Number column includes field replicate identifiers including: CR/SR/SQR which stand for Concurrent Replicate, Split Replicate and Sequential Replicate. These samples are taken as part of Northern Water's QAQC Procedures. For more information, please reference the Water Quality Monitoring Standard Operating Procedure.