How often the weather forecast data gets updated?

[STDataAndInformationService]

How often the forecast data gets updated?

Such as hourly, or 3 times a day, etc.

Thanks

[StephenClouse]

Forecast offices are supposed to update the forecast grids at least once every six hours. They may be updated more frequently during rapidly changing situations, such as severe or winter weather. There is no defined schedule for updates.