Prunus serrulata - Flowering Cherry

Prunus serrulata: Prunus, Latin for 'plum'; serrulata, meaning 'with small saw-like teeth,' referring to the serrulate leaf margins.

Trees bloom in early spring (late March in the SF Bay Area), later than P. cerasifera.
Showy flowers in deep pink to white can have a single whorl of petals...
...or multiple whorls of petals.
Fine hairs along serrulate leaf margins.
Leafed out.
Shiny, smooth grey bark with distinctive horizontal lenticels becomes rough with age.