The military currently have developed an integrated battlefield radar picture that takes all radar sources painting any target and integrates them into a composite 'objective' picture. Any fighter can then switch their radar off if necessary for stealth purposes and still get an accurate presentation via data link of the targets computed 'as if' from their individual perspective.
Similarly with TCAS we share our info on relative positions.
The recent extreme storms in Brisbane Australia demonstrated that extreme cell pictures vary, dependent on the relative direction of the radars. The weather radar North of BNE showed a quite different picture to the one South of BNE especially regarding the all important gaps between major cells.
It would seem not to difficult to integrate ground and air weather radars into a composite picture, particularity relating to dangerous cells. This is even simpler than the battlefield situation because we fly on narrow air routes in ideal, reciprocal directions.