Rain Check is a free and an optional bonus tool provided in the Tempest Weather app. The software provides a representation of the daily rainfall in your neighborhood. The Rain Check accumulation value can use raw data from the haptic sensor in your Tempest along with satellite & radar precipitation products and close by industrial gauges.
Because rainfall can vary so greatly over small distances, the goal of Rain Check is to provide a representation of daily rainfall at the "neighborhood" scale, rather than just the rain that landed exactly on your Tempest device. The Rain Check accumulation value starts with and depends on raw data from the haptic sensor in your Tempest, but it also considers other measures of precipitation in your area (including other Tempest devices). Rain Check compares the raw accumulation calculations from the haptic rain sensor against a reference data set described below to create an accurate representation of the average rainfall for your location.
It does not erase the saved raw data derived from the haptic rain sensor but it does replace the accumulation value shown in the app. You’ll know if you're seeing Rain Check data if the logo appears next to the rain accumulation value in the app. Rain Check data is provided in the app each and every day in the AM hours (exact times may vary depending on weather conditions).
Do I need Rain Check?
Rain Check is an estimate of rain accumulation received over a larger area. It's most helpful for Tempest owner's with siting limitations who can't install their Tempest sensor device under a clear view of the sky, for example if the property has a lot of tree cover. Also, while Rain Check is enabled, the software can automatically remove false rain data from the observation record; if you were to accidentally bump the Tempest device (which measures rainfall from vibrations) or if a bird lands on the device and causes vibrations, the data will be removed the following day if Rain Check determines there was no real rainfall.
If you turn Rain Check off in the app, all the raw haptic rain sensor measurements will return in the graphs and also in the station history. Turning Rain Check back on, will return the stored Rain Check data.
You can toggle Rain Check on or off in the advanced device settings in the Tempest app.
- Go to settings > stations > choose your station > manage devices > choose a device > Advanced > toggle Rain Check on or off for that device.
The Rain Check system currently only applies to stations located in the continental United States and some parts of Canada. WeatherFlow will continue efforts to make Rain Check or similar data available in other areas of the globe.
Rain Check accuracy has a lower confidence score in areas where brief showers/thunderstorms are frequent and large terrain influence is present.
A well-calibrated haptic sensor, in SKY or Tempest, installed on a stable mounting position, free of vibration, will produce rain accumulation values that are remarkably good compared to a standard conventional gauge. Rain Check will improve the accumulation values in cases where a particular device is not ideally mounted, which is difficult to do in most home locations (see these siting & installation tips for more details). If you believe your haptic sensor is experiencing significant accuracy issues over multiple rain events, please reach out to our customer support team and/or see here for info on rain calibrations.
Rain Check is a proprietary system that combines WeatherFlow device data with sophisticated 3rd party precipitation models that integrate up to seven (7) key precipitation data inputs to produce the most accurate rain accumulation estimate for a particular location. Precipitation inputs include: a reference network of over 25,000 quality-controlled precipitation gauges, climatological basemaps to account for complex terrain influences, a mosaic of state-of-the-science dual-pol estimated precipitation derived from NEXRAD radar sites, level-II radar reflectivity translated into a rainfall rate using standard Z-R algorithms, isopercental interpolation estimates in areas of complex terrain without adequate radar coverage, low altitude radar beam confidence rating to determine spatial suitability, and satellite rainfall estimates from NOAA’s Center for Satellite Applications and Research (STAR) known as “Hydro-Estimator”.