I have worked at my nation's meteorological office and they (and I'd assume others do too) provide this service. They do this by running an ensemble (at our off

I have worked at my nation's meteorological office and they (and I'd assume others do too) provide this service. They do this by running an ensemble (at our office, a population size of 50) with different starting conditions of numerical weather prediction models, rather than a single run. This will give you a confidence in the predictions of the numerical models. Besides general forecasting, they are also using this for hazard triggers so it can basically answer questions like "In the next 72 hours is there a 50% or greater chance that wind speeds will be higher than 30 knots at the biggest airport?".