The behavior of a vapor bubble growing and rising simultaneously in a uniformly superheated water was formulated taking into account of liquid inertia, heat conduction in the liquid and nonequilibrium effects at the vapor-liquid interface. Neither experimental data nor overall solutions for the bubble behavior in flash stage have been available as yet. Some illustrative numerical solutions for the entire bubble history were obtained for various superheats. A comparison between our theory and other theoretical solutions was also presented and discussed.