Probabilistic Tsunami Hazard Assessment (PTHA) for a coastal community or harbor can be performed by running a tsunami propagation/inundation code with initial seafloor deformations sampled from some presumed probability distribution of possible earthquakes. In addition to uncertainty in the tsunami source, tidal uncertainty has to be incorporated since the effect of a tsunami can be very different depending on the tide stage when waves arrive. For estimating risk in harbors and to coastal infrastructure, it is important to study flow velocities and momentum flux in addition to estimating potential inundation depth. Some new approaches will be discussed and illustrated in relation to a recent probabilistic study of Crescent City, California in joint work with Loyce Adams and Frank Gonzalez.