Have you wondered how stable are weather forecasts?
Since

let’s do a little test.

I’ve used a function getWeatherForecast {SmarterPoland} (github release) to download weather forecasts from the Dark Sky API. Hourly forecasts are downloaded every 10 minutes and stored in this repository based on archivist package (it’s easier to manage larger collection of objects). Having a bundle of forecasts I’ve plot them with the use of ggplot2 package and create an animation with the use of animation package.

And here it is (if you do not see the move above, click here).
Short movie with evolution of temperature forecast for The All Saints’ day in Warsaw.
Red curve – current forecast, grey curves – old forecasts, blue curve – history.

It’s funny that colder forecasts for first evening go with warmer forecasts of next morning.
And changes in weather forecasts are not that smooth as I’ve expected.