UK Met Office integration questions

I am implementing a frost warning in using the advice in https://community.home-assistant.io/t/weather-forecast-automation-get-notification-in-case-of-frost/866736 with data from the Met Office integration. When using weather.get_forecasts is the data returned from a local copy of the most recent fetch from the Met Office, or is another call made to the Met Office API? The Met Office API is limited to 360 calls a day and I want to avoid, unlikely as it probably is, reaching this limit.

Is there a way of triggering my notification code after the integration does its regular API calls to the Met Office?