NC Rain (Nearcast Rain) Follow

Overview

NC Rain is an additional data source provided via the Tempest Weather System, powered by Nearcast Technology. NC Rain data is an estimate of the average rainfall accumulation around your Tempest at the neighborhood level (roughly 100m x 100m). The NC Rain value is derived using measurements from your Tempest device as well as other relevant measures of precipitation such as radar, nearby professional rain gauges and other Tempest devices. NC Rain is our most valuable and useful indicator of rain accumulation for a given location.

Why is “neighborhood level” rain data important?

An individual Tempest device provides a rain measurement from a single point, while rainfall is not particularly uniform, even over short distances. Two identical rain gauges located relatively close to each other often report significantly different rain accumulation values. Because of this variability, the goal of NC rain is to provide an average representation of rainfall at a neighborhood scale, defined as roughly 100m x 100m. NC Rain provides a better estimate of rain accumulation for your neighborhood than can be provided using only (i) a single rain gauge on your property, (ii) a rain gauge (or gauges) some distance away, or (iii) radar data alone. Combining all valuable measurements produces the best representation of ground truth. Check out the CoCoRaHS interactive map of rain accumulation reports and see how some rain events can vary.

NC Rain data is the most useful data available for understanding rain near your location. And it can also be helpful to Tempest owners who aren't getting ideal rain measurements from their device, which can happen for a number of reasons. Normally, a well-calibrated haptic sensor, installed on a stable mounting position, free of vibration, will produce rain accumulation values that are as good or better than a standard conventional gauge. If you are concerned your haptic sensor is not working properly please see Troubleshooting Measurements & Data or contact us for assistance.

Availability

The NC Rain system currently only applies to Tempest Systems located in the following regions.

• continental United States
• southern parts of Canada
• UK and Ireland

WeatherFlow-Tempest is committed to making neighborhood level rain data available in other areas of the world.

Using NC Rain

NC Rain is enabled by default on Tempest stations where NC Rain data is available, and has a high accuracy score.

• You’ll know if you're seeing NC Rain data if the logo appears next to the rain accumulation value in the app.
• NC Rain data is provided in the app throughout the day (exact times may vary depending on weather conditions).
• NC Rain may exhibit some reduced accuracy in areas where brief showers/thunderstorms are frequent and large terrain influence is a factor.
• NC Rain values are a separate dataset and do not replace the direct rain measurements from the Tempest. When you turn NC Rain off in the app, the device's haptic rain sensor measurements will appear in the app, including graphs and station history. Turning NC Rain back on will return the stored NC Rain data.

Disabling/Enabling NC Rain Data

It is recommended to use NC Rain as your rain accumulation value and so NC Rain is enabled by default. If NC Rain is not preferred you can toggle NC Rain off in the advanced device settings in the Tempest Weather app.

Go to settings > stations > choose your station > manage devices > choose a device > Advanced > toggle NC Rain on or off for that device.

See more on Tempest System Rain Data.