The moon’s orbit is not perfectly circular. If it was then it would always be the same distance from the Earth and there wouldn’t be times when the low and high tides are lower and higher than usual.
This evening the moon is both a full moon and it’s within one hour of perigee, or the closest point in its orbit, which makes it a supermoon. According to NASA, it’s going to appear to be about 14% bigger and 30% brighter than when it’s at apogee (the farthest point in its orbit).
Very high tides accompany supermoons and this evening some nearby fishermen commented that the tides were higher than usual.