Originally Posted by
Bergerie1
It has happened before and will happen again. As others have said on this thread, aircraft weather radar is not very good at identifying hail. See this:-
Incidents and Accidents
WX radar is not good at painting dry hail which is normally at high altitude. It paints wet hail extremely well which would certainly have been the case in IST this time of year. In addition the radar will paint the cells that create the hail and in this case I understand the cell could be seen visually as well as being reported by ATC.
The dry hail issue being reported here is normally hail being spit out the top of a cell above 30,000 feet. Again the cell itself will paint however the hail can be tossed as much as 20 miles downwind of the cell and won't show up on radar until it gets below the freezing level and a film of moisture builds. This is the reason for the common advice to avoid enroute thunderstorms by 20 miles.