Staff at the Met Office are staging a one-day strike in a dispute over pay.
Members of the Prospect union will take industrial action today in protest at the Government's pay policy, which they say is widening wage gaps compared with the public sector.
The union said the Government's imposition of low pay rises was also restricting the Met Office's ability to close the gender pay gap.
Picket lines will be mounted outside offices, and workers will stage a lobby of Parliament.
Negotiator Helen Stevens said it was extremely rare for the weather specialists to take industrial action.
"Prospect members do not take this action lightly. They are loyal and committed to their work but they believe that the current pay policy is damaging the Met Office and its ability to serve its customers.
"The Met Office modernised its pay system in 2009, but the system has never been allowed to work. The impact is that women are being discriminated against and the Met Office is unable to recruit specialist staff.
"The Met Office needs these people to maintain the public weather service and realise the considerable benefits of the investment in the Met Office's new super-computer.
"The pay problems at the Met Office would not cost the taxpayer a penny extra to resolve. Prospect is simply calling on the Government to give the Met Office the freedom to manage its own paybill."
Prospect said more than five years of pay restraint was taking its toll on workers' lives, families and morale.
Steve Noyes, operations and customer services director at the Met Office, said: "The Met Office is aware that some members of staff intend to join the planned industrial action and we recognise their right to take this action based on a legal mandate.
"The Met Office provides forecasts and warnings to a wide range of customers from the public to British armed forces, broadcasters to the aviation industry and emergency responders to major sporting events. Our customers value the accuracy and quality of the forecasts and warnings we provide and we continue to work with them to ensure they will receive the best service possible.
"We are a modern, highly efficient organisation and because of the automated nature of many of our services they should not be impacted unduly by short-term industrial action. However, some disruption to services is possible and we are working to ensure those which are critical for safety of life and property are maintained.
"Weather forecasts and warnings will continue to be available to the public on our website."