How to predict the weather

Weather radars

Meteorological radars are specialized radars for determining the coordinates of precipitation, its type, direction of movement and intensity. They detect dangerous weather conditions such as thunderstorms, hail, as well as areas of intense precipitation and turbulence.

The appearance of such radars is associated with the Second World War: radio operators noticed the “noise” that arose on the instruments during precipitation. The study of this phenomenon led to the creation of specialized weather radars designed for the needs of meteorology.

Modern radars take a three-dimensional snapshot of the atmosphere every 10 minutes within a radius of 200-250 kilometers around them. This allows you to describe the weather up to the microdistrict. But for an accurate global forecast, there must be many of them. Here a problem arises: for example, Russian radars are located only in the European part of the country, as well as Novosibirsk, Barabinsk and Vladivostok. Another problem is the visibility of radars. High-rise buildings can block your view, creating blind spots, and low precipitation is invisible due to the curvature of the planet.Weather satellites are artificial satellites of the Earth, they are used to view and collect data on the weather and climate of the planet. They allow you to observe the weather over large areas, much like a view from a rooftop or mountaintop gives a wider view.

Weather satellites determine areas of intense precipitation and hazardous natural phenomena. The satellites track emissions from volcanoes and smoke from forest fires, the effects of pollution, sand and dust storms, and the boundaries of ocean currents.


The entire flow of weather data from weather stations, probes, radars, satellites, sensors on aircraft and ships goes to meteorological information processing centers – they are in every national weather service. Such centers are equipped with supercomputers. Less powerful machines would not be able to process this amount of data in a reasonable amount of time.

So, in the UK, the weather is predicted by the Cray XC40, which ranks 11th in the list of the most powerful supercomputers in the world with a performance of 7 petaflops (seven thousand trillion operations per second). Such a machine can predict the beginning of rain up to a minute. The main supercomputer of the Russian hydrometeorological service is inferior to the British one, its power is 1.2 petaflops.

The results obtained are analyzed by forecasters and make the final forecast. The machine considers specific characteristics, and only a person can generalize them. Forecasters make forecasts where there is a responsibility and where technology is not able to predict some of the weather on the ground, such as fog and ice.

How the weather is forecast today: forecasting models
Forecasters distinguish two main types of models: global and local.

Global Models

These models calculate the entire atmosphere of the Earth or a hemisphere. They take into account the vast weather systems that can stretch across the continent – cold fronts and severe storms.

There are several global models: American model (GFS), European model (ECMWF), German (ICON), English (UKMet), Canadian (CMC), Japanese (JMA), Russian (PALV) and others. Forecasters use mostly American and European.

American model (GFS). Created by the US National Weather Service. It runs four times a day: at 00:00, 06:00, 12:00 and 18:00 UTC. The results are published after 3.5 hours. Gives forecasts for 16 days ahead.

Access to model data is free. Anyone can download them on the official website. The popular website Windguru displays results based on the American model.

The computing power of the US model has grown tenfold over the past four years, and the model is now capable of eight quadrillion calculations per second.
European model (ECMWF). Named after the operating agency in Europe as a result of a partnership between 34 different countries. She makes predictions for 10 days ahead. Runs twice a day: at 00 and 12 hours UTC. Due to the complexity, it considers the forecast as much as 6 hours.

Access to data is paid. The results are displayed on the Foreca website. Gismeteo, Yahoo, Yandex and other popular resources take data from it.

The European model is, on average, more computationally powerful, while the American one sometimes gives more accurate predictions.