Hi Marigold,
Many thanks indeed for the very warm welcome!
In answer to your question, to the best of my knowledge, the WeatherEvents.net mobile weather lab is the only purpose-built/dedicated MWL currently operational in the UK. Happy to be corrected on that point mind you. 🙂 I know there are similar units operating in the US however.
You're right about the long gaps between the exciting bits in UK weather. 🙂 Fortunately I usually find something of interest either on the go, or on the models (even if it sometimes doesn't eventuate). :)
Anyway, thanks again for the welcome and great to be on-board here!