The problem, as I see it, is that TAFs are limited to what one can expect at a destination. The local TAF for me is in a different weather zone to my home airfield.
Looking at Airmet is less than useful as it is full of vague detail.
A few weeks back I flew through a weather zone that was unforecast on the sites I was able to access on my mobile phone. I'd phoned various airfields along the route and all assured me that the TAFs and METARs agreed and that the flight would be safe-ish.
In fact in 'bandit country' between the TAFs was an area of weather that was nothing like the surrounding TAfs were showing.
At my point of departure and arrival all was fine, but for a 15 mile area in the cruise, the weather was marginal, to say the least.
Being a VFR-only pilot that was 'interesting'.....