The results of visualization, thermal imaging and measurements of physicochemical parameters characterizing the crystallization of a metastable liquid are presented. An expression is proposed for the dependence of the crystallization front velocity of a metastable supercooled liquid on its physical properties and temperature. Numerical estimates of the temperature dependence of the energy barrier of supercooled water and the "reaction order" of the corresponding phase transition are obtained. On the basis of experimental data, the results of calculating the radiation intensity at the crystallization front as a function of the supercooling temperature are presented. Mathematical models of the investigated physical phenomena are offered.