Weather combined with experienced and well-trained pilots rarely causes an accident.
Weather combined in inexperienced and/or poorly-trained pilots has and still does cause fatal accidents.
AF447 is a classic example. The recent crash in Russia may be another, but the cause is not yet conclusive.
Weather radars improve with technology. Unfortunately, pilots seem to be going in the opposite direction due mainly to commercial pressure causing a race to the bottom in terms of the attractiveness of the pilot profession - longer hours, more fatigue, and lowering pay and conditions.
Flying with an airline that invests in and looks after it's pilots may actually be safer. Yes really!