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

    British Science Week: How are weather forecasts created?

09:00
16 March 2023

British Science Week
How are weather forecasts created?

Rainy window with sun drawn
Whether it's rain or sun, accurate weather forecasts are important in planning our day-to-day activates.

There is no better time to look deeper into meteorology than on British Science Week so today were letting you into 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.

You can find all of this work in action each and every day with your local forecast in the app, and see it visualised via the WeatherRadar.

Ryan Hathaway
More on the topic
Flood alerts after heavy showers. Risk in northern England. . . Thursday 20 August 2026
Weather radar map showing persistent heavy rain across northern England around Liverpool, Manchester and Newcastle, with a flood warning symbol highlighting the risk.
Thursday 20 August 2026

Risk in northern England

Flood alerts after heavy showers
Record warmth in the Mediterranean. High water temperatures. . . Tuesday 18 August 2026
Split graphic showing a hot southern Europe temperature map beside a sunny Mediterranean beach, with a sea-temperature icon highlighting very warm coastal waters.
Tuesday 18 August 2026

High water temperatures

Record warmth in the Mediterranean
Lightning strikes in dry conditions. Positive earth flashes. . . Monday 17 August 2026
On the left, massive thunderclouds are gathering at night, with several flashes of lightning streaking from them. On the right, a map shows the Ligurian coast near Genoa and Savona. Numerous coloured dots over the Ligurian Sea and along the coast indicate lightning activity.
Monday 17 August 2026

Positive earth flashes

Lightning strikes in dry conditions
All weather news
This might also interest you
Long-term trends need a pinch of salt. 40 °C in July?. . . Tuesday 30 June 2026
Temperature radar of 2022 heatwave where the all-time temperature record in the UK was set. Warning symbol overlain.
Tuesday 30 June 2026

40 °C in July?

Long-term trends need a pinch of salt
Historic Storm Éowyn arrives. On this day.... . . Saturday 24 January 2026
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
Turbulent weather in the Canary Islands. Storm and rain. . . Friday 12 December 2025
Weather graphic showing rain and wind fields over the Canary Islands and a central warning symbol.
Friday 12 December 2025

Storm and rain

Turbulent weather in the Canary Islands
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

facebooktwitteryouTubelinkList