Home
Weather London
WeatherRadar
RainfallRadar
TemperatureRadar
WindRadar
LightningRadar
Weather News
Editor's Pick
Discover the app
Weather widget
Contact us
Apps
Career
    Home / Editor's Pick /

    How are weather forecasts created?

07:00
15 March 2022

British Science Week
How are weather forecasts created?

There is no better time to look deeper into meteorology than on British Science Week. Starting with the world of forecasts.

Meteorologists use some of the world’s most powerful super-computers to produce our weather forecasts.

These incorporate a vast amount of data and perform trillions of calculations per second to give us an idea of how the weather will change in the coming days.

Due to the complexity of the atmosphere however, even these weather forecasts tend to only be reliable for up to five days or so.

If the weather conditions are particularly complex, there can still be a degree of error even within the five-day period.

Any forecast that offers an outlook greater than ten days’ time is not considered a forecast but a trend.

To produce these forecasts, meteorologists usually run their forecast models a number of times and group the forecasts into what are known as clusters.

This gives probabilities of what may happen in the future, rather than one single solution.

Short-term forecasts cover a period of 24 hours up to three days. We see these on the TV every day. They are generated using synoptic meteorology – current atmospheric observations – and numerical models.

Medium-range forecasts cover between three and 10 days with long-term forecasts covering periods over 10 days away. Both are generated by using weather ensemble models to create a weather trend.

For both ranges, conditions tend to be described as wetter or drier, warmer or cooler with no specific information.

Ryan Hathaway
More on the topic
Wind forecast map of the UK and northern Europe showing strong orange wind zones around a low-pressure system marked with a white “L,” alongside a black-and-white windsock warning icon.
Tuesday, 12 May 2026

Gusty conditions ahead

Low pressure brings windy days
Satellite weather map of the UK and western Europe showing rain bands across Britain, a rain cloud icon over Scotland, and a thunderstorm icon near Belgium and northern France on Wednesday 13.05.
Wednesday, 13 May 2026

Hail also possible

Thunderstorm risk for parts of the UK
Radar image showing a thunderstorm cell over northern Italy, near Brescia and Bergamo. Next to it, several large white hailstones in a hand.
Tuesday, 12 May 2026

Severe storms in Italy

Damage caused by large hailstones
All weather news
This might also interest you
Outline of Santa Claus with a yellow and white hat, "Ho-Ho-Ho" next to the outline above a Christmas tree.
Thursday, 25 December 2025

Merry Christmas!

Wishes from Weather & Radar
Split image showing aerial flooding in a town with muddy water covering roads on the left, and a rural road on the right blocked by heavy snowfall with vans stopped and a person walking in snow.
Tuesday, 27 January 2026

Storm Chandra

Flooding, gales, and heavy snow
Split image showing a person in a yellow jacket struggling against strong winds and heavy rain on a street at night on the left, and an Irish wind forecast map on the right with red and purple shading, gusts up to 75 mph, and a wind warning icon, divided by a curved white line.
Saturday, 24 January 2026

On this day...

Historic Storm Éowyn arrives
All articles
Weather & Radar

Weather & Radar is also available on

Google Play StoreApp Store

Company

Contact us Privacy Policy Legal info Accessibility statement

Services

Uploader

Socials

facebooktwittertikToklinkList