The absolute values of probabilities of the radiative I¹ Π_g ^-, ν, ′, N → B¹ Σ_u ⁺, ν″, N transitions of the H₂ molecule are obtained for the first time for values of the vibrational quantum numbers ν′= 0-3 and ν″ = 0-9 and the rotational quantum numbers N= 2-6. The calculations are carried out using a nonadiabatic model developed in our previous papers, which takes into account the electronic-rotational interaction of the 3d¹ Π_g ^-, ν′, N and 3d¹ Δ_g ^-, ν′, N levels. Semiempirical data on expansion coefficients of the total wave functions of I¹ Π_g ^-, ν′, N states in the Born-Oppenheimer basis of the 3d¹ Π_g ^-, and 3d¹ Δ _g ^- states are used. The dependence of the dipole moment of the 3d¹ π_g → 2p¹ Σ_u ⁺electronic transition on the internuclear separation r is determined both from our semiempirical data and from results of a nonempirical calculation available in the literature. It is found that the discrepancy between values of rovibronic transition probabilities, obtained on the basis of nonempirical and semiempirical data on the dipole moment of this transition, is, on the average, about 30%.