Windy.app Weather Forecast Models

Windy.app Weather Forecast Models

Learn about weather forecast models used in Windy.app.

The weather depends on lots of different factors: wind speed, cloudiness, pressure, humidity, etc.

All of them can be measured and represented in meters per second, millimeters of mercury, etc. A mathematical weather model is a combination of all these factors. Such models tend to be very complex, powerful computers calculate them.

Usually, weather models are provided by national weather services, but sometimes they can also be produced by groups of enthusiasts. In this section, we want to introduce you to our models, from which we get forecasts.

Windy.app has two types of forecast predictive models: global — on the map, and local — for a spot.

Model Region Grid, km Forecast depth, days Step, hours Daily updates, time/day
ECMWF Global 14 10 3 2
ECMWF-ENS Global 27 3 1 1
GFS27 Global 27 10 1 4
GFS+ Global 27 10 1 4
ICON 13 Global 13 5.1 1 4
ICON 7 Europe 7 4.7  1 4
NAM North America 12 2.5 1 2
WRF8 Europe 8 3 3 1
Open Skiron Mediterranean 12 5 3 1
Open WRF Mediterranean 12 4 3 4
AROME France 1.25 1.7 1 4

ECMWF — Global

A global model by the European Centre for Medium-Range Weather Forecasts. Considered the best for precipitation and cloudiness. Resolution — 14 km. Updates every 12 hours, providing forecasts for 10 days.

ECMWF-ENS (Ensemble Model) — Global

EC-ENS Ensemble Model — precise data for more than a 3-day forecast.

Sometimes, forecast models may be wrong and meteorologists came up with a clever solution. They use the same model all over again but input slightly different data. For example, the wind speed was 3 m/sec, but they input it as 3.3 m/sec. This way the parameters of the models are slightly modified.

Given these new parameters, they develop a new weather forecast. Then repeat this 40 times getting 40 different forecasts.

If the lines on the graph are spaced widely apart, then you should not rely on the forecast too much. And if the lines are close together-the the determined forecast is reliable. This feature allows you to be sure in a forecast when there is no reason to question it, but will also help you to recognize in advance the low probability of a forecast due to a difficult weather situation. Ensemble Model is indispensable if you need the most accurate forecast for more than three days in advance.

Read more about Ensemble Model.

GFS27 — Global

The US Global Forecast System, originally created for aviation. Updated 4 times a day, providing forecasts for 10 days.

GFS+ — Global

While the GFS27 interpolates data for every dot within a 27 km x 27 km square, the GFS+ always shows only the maximum result in each square. Updates 4 times a day, forecasting for 10 days.

ICON13 — Global, ICON7 — Europe

A global model by Deutscher Wetterdienst (German Meteorological Service).

For Europe, higher resolution (7 km) is available for the ICON model, making it even more precise than the ECMWF. The ICON with a 13 km resolution is the global version available worldwide.

  • ICON7 — updates 4 times a day, every 6 hours. Provides forecasts for the next 5 days.
  • ICON13 — updates 8 times a day, every 3 hours. Provides forecasts for the next 5 days.

NAM — North America

Developed specifically for North America, provides the most precise forecast for the region. Resolution — 12 km. The forecast is updated 2 times a day. Provides forecasts for the next 61 hours.

WRF8 — Europe

The WRF is a model for weather forecast calculation developed by several scientific laboratories in different countries.

Using it, Windy.app calculates a hyperlocal forecast for Europe and the Mediterranean. Updates once a day, giving forecasts for the next 3 days.

OpenSkiron — Mediterranean

A local model developed at the University of Athens. Considered one of the best for the Mediterranean. Resolution — 12 km. Updated once a day, providing forecasts for the next 5 days.

OpenWRF — Mediterranean

A local model for the Mediterranean. Based on the WRF technology, adapted by the University of Athens and a group of enthusiasts. Resolution — 12 km. Updated 4 times a day, giving forecasts for the next 4 days.

AROME — France and the surrounding territories

A local model developed by Meteo France (French meteorological service). Covers France and some adjacent regions. Resolution — 1.25 km. It is updated 4 times a day and provides forecasts for the next 42 hours.

 

Read about the advantages of each model and lots of other useful info in the guide on forecast models all around the world.

If you want to get the most accurate forecast for a rather long period of time, you will find the EC-ENS Ensemble Model feature very useful. Learn more in our review "How to Use Ensemble Models for Weather Forecast".

 

Cover photo © markusspiske / Unsplash