I don't know what's available in Europe, but here in North America, anybody with an internet connection, including dispatchers, can see radar for the entire United States plus the Southern part of Canada.
A dispatcher here who sees a flight with thin reserves headed into an area where CBs are blooming at destination and alternates within range will likely be diverting that flight to an airport in good weather where additional fuel can be taken on.
There is work under way to upload radar to the cockpit so that the crew can take advantage of national radar data:
NASA Report