The data for these gauges is pulled from the Mesonet website, but the data originates from other sources. These sources include
– Automated Flood Warning System
– RAWS
– Advanced Hydrologic Projection Service
– Possibly other sources
The data from these gauges is problematic in that most of them record and transmit readings at irregular time intervals. In contrast, the data in 'Gauges' map layer originates from USGS and HADS and is reported in 15 minute intervals. That makes it easy to calculate hourly summaries of the data that are shown under the rain drop icons and determine which arrow icon (rising/falling) to display for the stream gauges. But this is not so easy with the irregular nature of the secondary gauges. It appears that many of the secondary gauges do not transmit data when there has been no or little change in rainfall or a stream's stage. Many hours can elapse between readings in these cases. Then some gauges only report data at 12 hour intervals. Both of these scenarios can make it impossible to accurately report the amount of rain in the past 6 hours. Because of these difficulties, please be aware that the 6/12/24 hr labels under the rain drop icons may be misleading – sometimes very misleading. Also be aware that a river may have started to rise but the direction of the arrow may not reflect that change or any other change. It's best to click on the gauge icons and then review the graph and data table that are shown. Pay close attention to the timestamp of the last several readings.
Because of the potential misinterpretation with the secondary gauges, I decided to put them in a separate map layer that you can turn off using the “Layer Switcher” on the desktop map or by clicking the “Layers” button on the mobile version of the map. I've also used different colors for the icons: the rain gauge icons are light blue and the stream gauges icons (arrows) are gray.
Please note that the secondary gauges are a work in progress. People in the IT industry might say that they are “in beta.” I already have a short term to do list includes:
– Identify gauges that haven't reported data in more than 24 hours and display a warning symbol on the gauge, such as a red exclamation mark
– Identify gauges that haven't reported data in weeks and remove them from the map.
– Remove duplicate gauges. Some of these secondary gauges appear to be in the USGS or HADS systems as well. The gauge in the secondary gauges layer will be deleted in these instances.
– Visually review the rain gauge labels (6hr/12hr/24hr) and the stream stage arrows to determine if they're communicating good information
I'm open to comments and suggestions. Please feel free to post them on the Rain Pursuit Facebook Page or send me and email at alexzendel at hotmail dot com.