Meet the new hyper-local ICON-D2 weather model for Central Europe

We are pleased to announce an important addition to the list of weather models used in the Windy.app — ICON-D2. Thanks to its high resolution, it takes into account the terrain and also predicts severe weather better, which makes it excellent for adjusting your plans for today and tomorrow. Now for the details.

ICON-D2 weather model in the Windy.app for iOS with the weather forecast for Vienna, Austria, in Central Europe

Source

ICON-D2 is a regional hyper-local weather model for Central Europe from DWD (Deutscher Wetterdienst), the German national weather service. It is the third main model in the service’s collection after the global ICON13 and regional ICON7 also known as ICON-EU (Europe).

Main features: hydrostatics, topography and severe weather

The name of the model itself stands for Icosahedral Nonhydrostatic, where the second word means that it uses altitude in the forecast, i.e. more accurately takes into account the influence of the terrain on the weather — just like ECMWF, the main global weather model in the world and also the only one using this principle (hydrostatic models use atmospheric pressure instead of altitude). In the vertical resolution, the ICON-D2 model defines 65 atmosphere levels.

According to the DWD’s official website, "due to its fine mesh size, the ICON-D2 especially provides for improved forecasts of weather events that are influenced by fine-scale topographic effects: ground fog, Föhn winds, intense downslope winds, flash floods."

It also gives better forecasts "of hazardous weather conditions, e.g. weather situations with high-level moisture convection: super and multi-cell thunderstorms, squall lines, mesoscale convective complexes".

Territory

The ICON-D2 model is available for Central Europe, which means that considering also the country of its origin, it covers all of Germany, Benelux (Belgium, the Netherlands, and Luxembourg), Austria, Switzerland, and parts of the other neighboring countries. The region without precise boundaries may also include at least Poland, the Czech Republic, and Slovenia, depending on the angle of view.

Outdoor spots of Central Europe on the Weather Map in the Windy.app for iOS

Spatial resolution

The spatial resolution of the ICON-D2 model is 2.2 km (1.3 mi), which means it is not merely regional, but hyper-local. It is the DWD’s highest-resolution model. For comparison, the ICON-7 is 7 km (4.3 mi), as its name implies. It is now also one of the two most local regional models for Europe in the Windy.app collection on par with AROME (1.25 km / 0.7 mi) for France and neighboring territories. It also ahead of the regional WRF3 model for East Asia and the HRRR model for the US with a 3 km / 1.8 mi resolution each.

Forecast depth

The forecast depth or length or dutation of the ICON-D2 weather model is also a very-short range — 27 hours or 1.1 days (one day and three hours). Therefore, the model is excellent for adjusting your plans for today and tomorrow. But the model run at 03 UTC even gives a forecast for the next 45 hours. So at the end you can have ICON-D2 forecast for the next 48 hours starting from 00 h.

Forecast step

As in other ICON models, the forecast step or its division within a day is 1 hour.

Update frequency

As compared to other models, the ICON-D2 updates also with high frequency, namely 8 times a day, i.e. every three hours with the same step of the forecast during the day. DWD counts the forecast at 00, 06, 09, 12, 15, 18, and 21 UTC (Coordinated Universal Time). Again, by comparison, ICON7 is updated 4 times a day, while WRF8(3) and HRRR are updated only once a day.

Weather elements

In the Windy.app you will find the following 11 weather parameters on ICON-D2, including all the major ones except visibility and UV and AQ indices, and some advanced ones including two charts:

Weather condition
Air temperature
Wind speed
Wind gusts
Wind direction, cardinal
Wind direction, °
Atmospheric pressure at sea level
Clouds and precipitation
Rain and snow chart
Relative humidity
Clouds (cloud coverage)

Summary

Let us summarize the data of the ICON-D2 model:

Territory: Central Europe: Germany, Benelux (Belgium, the Netherlands, and Luxembourg), Austria, Switzerland, and parts of the other neighboring countries
Spatial resolution: 2.2 km (1.3 mi)
Forecast depth: 2 days (48 h)
Forecast step: 1 h
Expected update: 8 times a day (every 3 h)
Weather elements: 11 (8 main and 3 advanced)

How to activate the ICON-D2 model in the Windy.app

To check if a model works in your area, simply go to the spot and find and select it in the list of weather models under the wind rose — e.g. Vienna, the capital of Austria. If the model is not listed, then it does not cover the selected spot.

Weather elements of the ICON-D2 weather model in the Windy.app for iOS

To find all the parameters of a model, switch weather profiles through the icon on the right side of the models list or create a custom profile exactly with this model.