[en] The changes of the processes of the (²¹⁰Po) admixture washout when the admixtures are injected into a certain point of the cumulo-nimbus cloud during the rain with the drops of a definite size at different precipitation intensity is studied. The bulk of the ²¹⁰Po amount injected above the experimental site was washed out for 9-14 min. The greatest ²¹⁰Po concentration in the raindrops was observed as the rain intensity decreased in the points below the large drop size cumulo-nimbus cloude zone. The bulk of the admixture was washed out by drops of the radii 0.8-0.9; 1.2-1.3 and 1.8-2.0 mm. The quantity of ²¹⁰Po washed out by the drops of these sizes depends on the distance between the tracer injection point and the fallout of the precipitation as well is on the injection moment during the rain