Tides this weekend will seem more extreme than we usually see. The astronomical reason is tied to the gravitational pull of both the moon and sun, pulling together. The moon is closer to Earth than usual, in perigee and it is also near the New Moon phase. With the Sun and Moon sharing a similar part of the sky, their gravitational pull will have a more than usual pull on our oceans.

The tides will seem highest at midday and near midnight. Low tide will be in the morning near sunrise and again at night near sunset. At high tide, sand bars that are normally hidden in our coastal ponds will be exposed. At the other extreme at high tide, the shoreside wrackline will be pushed inland higher up the beach.

Whenever the moon is either full or in the New Moon phase and it is also in perigee, our oceans get a more than usual gravitational pull. The moon’s orbit around the earth is not a perfect circle. It is elliptical. Once a month the moon is close and it is at perigee and at the other extreme the moon is far and that is called apogee.

The moon’s changing distance from the earth is not tied to the phases of the moon. Sometimes our full moon is at apogee or in perigee or somewhere in between.