What is HRRR weather model and how it works

The HRRR weather model is one of two major regional weather forecast models for North America, on a par with the NAM weather model. In other words, if right now you're looking at the weather forecast for the US, Canada, or Mexico, it's probably from one of these two models.

In this post, you will learn about the HRRR weather model, its working principles and the main features, and where to find the weather forecast by this model.

What is HRRR weather model?

The HRRR (High Resolution Rapid Refresh) is regional weather model for North America made by the National Oceanic and Atmospheric Administration of the US (NOAA). It provides a great forecast for the continental United Stated, Canada and Mexico based on radars' data — the unique advantage of HRRR. It is assimilated every 15 min over a 1 h period. It gives short-range weather forecasts with pretty good accuracy.

The official website of the model is Rapidrefresh.noaa.gov/hrrr.

What are the main features of HRRR weather forecast model and how it works?

The HRRR model has a resolution of 3 km (1.9 mi). The resolution is the distance between two points of the weather model grid. Bigger resolutions of 50 to 10 km in size are usually deployed in relatively flat terrains, while mountain ranges require the nodes to be a lot closer to each other, usually 5, 2, or 1 km.

The forecast depth of HRRR weather model is 1.5 days or 36 hours. The depth of the weather forecast is the number of hours or days for which the forecast is made. As a rule, the lower the depth, the more accurate the forecast.

The HRRR forecast step is 1 hour. The forecast step is for how long you can see a forecast in the application or on a website. There are two main step types: 1 h and 3 h.

The HRRR expected update is 2 times a day (every 12 hours). The update frequency of the forecast is the regular time interval after which new forecast data is received from the supercomputers. There are other models like HRRR with 24 times a day updates, but in general, the frequency of the updates of weather models is 1, 2, or rather 4 times a day.

Let's sum up the main features of HRRR model:

Resolution (grid): 3 km (1.9 mi)
Depth (period): 1.5 days
Step: 1 h
Expected update: 2 times a day (every 12 hours)

Where to get the weather forecast from the HRRR model in Windy.app?

The HRRR weather model is also the main weather model in Windy.app among 10+ other models. In the app, the model has the same 3 km resolution. To get a weather forecast:

1. Open your favorite or the nearest spot to your current location in the United States, Canada, or Mexico in the app from the Home Screen or the Weather Map. For example, the Olympic National Park located on Olympic Peninsula in the Washigton state near the city of Seattle in the United States. To see the nearest spots, allow the app to see your location in Settings.

Home Screen in the Windy.app for iOS

Olympic National Park hiking spot on the Weather Map in the Windy.app for iOS

2. Choose HRRR weather model in the slider under the Wind Rose:

Olympic National Park weather forecast from the HRRR weather model in the Windy.app for iOS

3. Read the weather forecast from the HRRR model for your particular sport. For example, the spot considered good for hiking even in the rain, kayaking or professional fishing. In Windy.app you can get the following weather parameters from the HRRR choosing different Weather Profiles for other sports like surfing, biking, skiing, and a few more:

Wind direction (both cardinal and degrees)
Wind speed
Wind gusts
Air temperature
Clouds
Precipitation

(On the screen, there are also additional weather parameters like solunar forecast, atmospheric pressure at sea level, moor riese/set, for example, which comes to form the different models.)

Weather parameter of the HRRR weather model in the Windy.app for iOS

In addition, you can have the general weather conditions: sunny, rainy, cloudy, etc. from the HRRR weather model choosing the Lite Weather Profile. They are represented by an icon. Learn how to read these weather symbols.

Weather conditions of the HRRR weather model in the Windy.app for iOS

In the same Lite Weather Profile you can also get Rain and Snow Chart:

Rain and Snow Chart from the HRRR weather model in the Windy.app for iOS

4. Choose or delete one of these weather parmeters using the Customization feature. That's how you will make your own custom weather profile in Windy.app:

Fish Weather Profile in the HRRR weather model in the Windy.app for iOS

HRRR weather model parameters in the Customization feature in the Windy.app for iOS

5. Compare weather data from HRRR model to other models in Windy.app using special Compare Mode professional feature:

Comapre Mode feature in the Windy.app for iOS

6. Compare HRRR weather forecast with data from the three nearest weather stations to the spot thanks to special Windy.app feature based on data directly from these stations. They are always located on the same spot's screen. Learn how to read weather stations screen in the Windy.app:

Nearest Weather Stations feature in the Windy.app for iOS

Weather Station Port Angeles (HURW1) screen in the Windy.app for iOS

7. Return to the Weather Map map to see the bigger wind picture in the region from the HRRR model. To do so, choose it from the slider on the map:

HRRR weather model on the Weather Map in the Windy.app for iOS

Read about ECMWF, ECMWF-ENS, GFS, ICON, NAM and other weather forecast models used in Windy.app. Read the complete guide to all major weather models in the world.

Text: Ivan Kuznetsov, an outdoor journalist, editor and writer from the Dolomites, Italy, and Karelia, Finland, with 10 years of professional experience. His favorite sports are hiking, cycling and sauna. Read his other articles

Cover photo: S-migaj / Pexels