A Cold Swim
It always amuses me every Memorial Day weekend how many flock to the shore to swim. Now if I suggested you go to the beach and swim on the Thanksgiving holiday you'd think I had lost it. Well, the ocean is actually warmer on Thanksgiving Day than it is on Memorial Day. Sure the air temperature is usually warmer but this tidbit always takes everyone by surprise. The water temperature on Thanksgiving is around sixty four degrees but on Memorial Day it's only around sixty one degrees. We have talked about the high heat capacity of water. That means it takes a lot of energy to change the temperature of water. The ocean is still recovering from winter and it hasn't received the added boost from the Gulf Stream. The atmosphere is vertically mixed but the oceans are horizontally mixed. That means layers of the same temperature and while these layers mix a little they do not mix over great vertical distances like the troposphere. If the kids insist on taking a dip please do not let them stay in very long. Maybe limit swimming to a half an hour at a time before coming out and warming back up. I'm not trying to be a buzz kill but you can get hypothermia in water that cold. When water temperatures are between fifty and sixty hypothermia can set in between one and two hours. The sun won't feel that hot but late May sun is the equivalent to July sun so keep applying the sunscreen. It will be so chilly this Memorial Day weekend folks should be less tempted to jump in the water. Welcome to summer !