Wednesday, April 20, 2022

Perigean Tides


Please click on this picture to see it full size.  We were a day late going to the beach for our coffee and donut this week.  I was stunned to look out at the harbor and see a sandbar that was exposed, with birds sitting on it.  I have never seen a tide this low before!   The sandbar was about a third of the way across the harbor.  The distance across the water here is just about half a mile and the darker water in the distance is where the marked channel is.  When the tide is in, it looks as if you can sail anywhere, but you can't and I have seen large sailboats and powerboats tipped  to one side because they ran aground and then tide then went out.  Follow the buoys, captain!  This is pretty subtle to discern, but I hope you can see that the wet sandbar has no water on it.  NOAA, the National Ocean and Atmospheric Administration explains it this way, and they PREDICTED this low water:  “When you may experience higher and lower than normal tides between March and May 2022. Dates:  April 18-20. Why will they be higher or lower than normal? In May, a perigean spring tide will be occurring. This is when the moon is either new or full and closest to earth. Higher than normal high tides and lower than normal low tides will occur. Tides will increase leading up to and after the June 21 summer solstice, due to the position of the sun relative to the earth's equator.” So there you have it, right from the horse's mouth!


 

3 comments:

ken schwarz said...

Aye, Aye Captain!

Anonymous said...

Thanks for researching and giving us another informative lesson today. Very interesting.
Joan

Anonymous said...

That is pretty scary for boaters who are not aware of the situation! Nice photo and interesting information. betsey