Get reliable science

It is common on rangelands to have large gaps of distance between �official� rain gauges and gaps of time (up to 365 days) between measurements. Those gaps make it difficult for managers to understand the impact of precipitation on rangeland resources and the response of those resources to management. We developed the web-based myRAINge Log (https://myraingelog.arizona.edu) to help managers and ranchers organize and interpret their precipitation observations and fill those gaps. We reference measures to the SPI, Standardized Precipitation Index because 1) it is widely used to represent drought severity, 2) a minus 1 SPI (12-month window) triggers on-site evaluations for all livestock grazing allotments in Region 3 of the National Forest system, and 3) it provides a likelihood-based reference for current conditions. We rely on data from the PRISM gridded climate dataset (~4km, 1981-2016) to provide the interpolation-based estimate of amount and timing of precipitation. For data entry, myRAINge Log allows the user to 1) establish an infinite number gauges across the conterminous U.S., 2) enter precipitation values up to 1-y apart, and 3) enter photographs and field notes for each measurement date. For interpretation, myRAINge Log allows users to 1) select the time period for representing the accumulation of precipitation, 2) examine the amount of precipitation recorded in the gauge at that location, 3) compare the amount of recorded precipitation to the PRISM-based estimate of precipitation, and 4) compare the amount precipitation to the SPI values of probability. Since deployment in June 2017, users in Arizona report benefits of comparing actual measures to vegetation abundance, and the Forest Service minus 1 SPI �drought policy�. In addition, users found benefit in understanding the frequency of precipitation events between measurements, and the projection of precipitation that occurred since the last measure and the current day.