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 | 6 | 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 |
HRRR | North America | 3 | 2 | 1 | 24 |
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 |
Other data in the table:
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.
A global model by the European Centre for Medium-Range Weather Forecasts. It is precise data for more than a 3-day forecast. Resolution is 27 km. Updates one a day, forecast for 10 days.
Learn more about ut in an article "How to Use Ensemble Models for Weather Forecast".
The US Global Forecast System, originally created for aviation. Updated 4 times a day, providing forecasts for 10 days.
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.
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.
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.
HRRR is High Resolution Rapid Refresh. The model was developed by the National Oceanic and Atmospheric Administration (NOAA) of the US.
It provides a great forecast for the continental US with real-time 3 km (1.9 m) grid resolution, hourly updates and radars' data — the unique advantage of HRRR.
It is assimilated every 15 min over a 1 h period. It gives short-range weather forecasts (forecast depth is 18 hours) with pretty good accuracy. So the forecast from HRRR is definitely worth looking at.
In HRRR you find temperature (2 m), gusts (10 m), wind speed and direction (10 m), total cloud cover on your spot forecast screen.
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.
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.
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.
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 in Windy.app blog.
Cover photo © markusspiske / Unsplash