1. ITV Report

A hundred years of military weather forecasting

The military weather chart produced by the Met Office 100 years ago Credit: Met Office

It’s been 100 years since the first weather forecast was provided for the British Armed Forces by the Met Office.

From the Battle of the Somme to current operations and exercises around the world, the Met Office has provided the latest forecasting information to better inform military commanders in their operations and exercises.

Although the Met Office were producing synoptic charts and covering North West Europe throughout World War One, these were only used for work in the UK. The first general forecast for the British Army was not until 24 October 1916.

The importance of meteorological forecasts has since always been considered critical and the Met Office has operated 24/7 since this day in 1916.

Met Office archivist Catherine Ross says it offered its services at the start of the First World War but was told "the army doesn't go to war with umbrellas".

  • Listen to the fascinating story of how Met Office military forecasts came about
Unseasonably heavy rain turned the battlefield at Passchendaele into an expanse of deep mud Credit: PA

The operational forecasts proved to be highly important and, after what was one of the only allied advances during the battle of Passchendaele, one of the senior allied commanders sent a telegraph to Meteor R E to thank them for their accurate forecasts - which had proved great help in planning the operation.

The Met Office played a key role in deciding the timing of the D-Day landings in 1944 Credit: PA

Famously, the forecasts provided by the Met Office played a crucial role in the timing of the D-Day landings in Normandy known as Operation Neptune.

After calculating that the moon and tide conditions would only be simultaneously favourable on the 5, 6 and 7 June, meteorologists advised commanders to push back the operation from its originally anticipated date in May. This forecast was one of the most important in world history and was hugely important to the war’s outcome.

A tiny part of the massive supercomputer that calculates the weather nowadays Credit: ITV News

Nowadays the Met Office, which is now based in Exeter, attracts international attention, with allies such as the US and NATO drawing on data, advice and services from the Met Office as well as those of their parent national or military meteorological bodies.

It has also seen a huge transformation in technology - 100 years ago staff drew charts by hand every few hours - nowadays they have access to the latest technology, including one of the most powerful supercomputers in the world, which also guides ITV's forecasts.