What is Windy.app's WRF8 weather model and how it works

The WRF8 weather model is a special regional model for Europe and East Asia developed by the Windy.app team. In this post, you will learn more about this model, its working principles and the main features, as well as where to find the weather forecast by this model in the app.

What is WRF8 weather model?

The WRF8 is a regional weather model developed by the Windy.app's R&D (Research and Development) team based on WRF technology (Weather Research and Forecasting).

In particular, WRF was a result of a collaborative effort of a group of enthusiasts in several scientific laboratories in different countries across the globe in the 1980s. It is a codebase for further forecast model processing. It is applicable globally and can take local geography and topography into account. It has a wide range of different physical parameters and demands vast resources to process.

Using this model, Windy.app calculates a hyperlocal forecast on our servers for Europe and the Mediterranean Sea, including its coastal areas of Spain, France, Italy, Greece, Montenegro and other countries, as well as for East Asia: Japan, South Korea and surrounding territories.

Except Windy.app, many institutes and organizations use the WRF as a base to develop their own regional models.

The official website of the model is Narac.llnl.gov.

Weather forecast for Rome, Italy. Photo: Alexander Popov / Unsplash

Weather forecast for Seoul, South Korea. Photo: Ka Long Li / Unsplash

What are the main features of WRF8 weather forecast model and how it works?

The model has a resolution of 8 km (4.9 mi) for Europe and 3 km (1.8 mi) for East Asia. 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 is 3 days (72 h) for Europe and 1.5 days (36 h) for East Asia. 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 forecast step is 1 hour for both regions. 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 updates frequency is once a day (every 24 h) for both regions. The update frequency of the forecast is the regular time interval after which new forecast data is received from the supercomputers. 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 WRF8 model:

Resolution (grid): 8 km (4.9 mi) for Europe and 3 km (1.8 mi) for East Asia
Depth (period): 3 days (72 h) for Europe and 1.5 days (36 h) for East Asia
Step: 1 h for both regions
Updates: once a day (every 24 hours) for both regions

Where to get the weather forecast from the WRF8 model in the Windy.app?

The WRF8 is the one of the main model in the app among 10+ others. To get a weather forecast, do the following easy steps:

1. Open your favorite spot or the nearest one to your current location in Europe or East Asia in the app from the Home screen or the Weather map. Let's take the capital cities of Russia and South Korea — Moscow and Seoul — as an examples. To see the nearest spots, allow the app to get your location in Settings.

Home screen of the Windy.app for iOS

Moscow on the weather map in the Windy.app for iOS

2. Choose WRF8 weather model in the slider under the Wind rose:

WRF8 weather model in the weather forecast for Moscow, Russia, in the Windy.app for iOS

3. Read the weather forecast from the WRF8 model for your particular sport. In the Windy.app, you can get the following weather parameters (elements) from this model, choosing different Weather Profiles for sports like biking, hiking, skiing, and a few more:

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

(On the screen below, there are also additional weather parameters depending on the weather profile like bicycle riding temperature, relative humidity, which comes from the different models.)

Weather parameters of the WRF8 weather model in the Windy.app for iOS

In addition, you can have the general weather conditions: sunny, rainy, cloudy, etc. from the WRF8 weather model choosing the Lite Weather Profile. They are represented by an icons. Learn how to read these weather symbols.

Weather conditions from the WRF8 weather model in the Windy.app for iOS

In the same Lite Weather Profile you can also get Rain and Snow Chart. Then, if you choose other profiles, you will also get Clouds and Precipitation Chart. So there are two charts in total.

Rain and Snow Chart from the WRF8 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 the Windy.app:

WRF8 weather parameters in the Customization feature in the Windy.app for iOS

5. Compare weather data from WRF8 to other models in the Windy.app using special Compare Mode professional feature:

Comapre Mode feature in the Windy.app for iOS

6. Compare WRF8 weather forecast with data from the three nearest weather stations to the spot thanks to special Windy.app feature based on data received 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 Gyeonggi-Do-Seongnam-Si (RKSM) screen in the Windy.app for iOS

7. Return to the Weather map to see the bigger wind picture of the region from the WRF8 model. To do so, choose it from the slider on the map:

WRF8 weather model on the Weather Map in the Windy.app for iOS

Read about other weather forecast models used in the Windy.app, as well as 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: Sylvain Mauroux / Unsplash