Whether rocky, sandy or jagged coastline, beaches are always an ideal spot for summer downtime. Even the landlocked states vacation on coastlines to experience the wonderful climate of the sea. Unless, a storm is rocking against the shore, beaches usually have the ideal weather.
So, you were thinking about having a beach day tomorrow and you want to check the weather to make sure it will be a nice day. You turn on the TV or look at the map online and get confused because the meteorologist is talking about air pressure. What the heck does pressure have to do with weather? Well…
Air converges at low pressure. When air converges at the surface, it causes air to rise. As the air rises it cools and condenses. As condensation occurs, water droplets attach to hydroscopic particles inside the forming clouds. Water droplets become ice crystals high in the atmosphere. Unless the air near the surface is below freezing, they melt as they fall. Therefore, low pressure areas often forecast precipitation. This is not what you want on your beach day. High pressure generally has warmer temperature and clear skies.
So, if you see a big upper-case L hovering over your location, you might want to stay indoors. Just be warned, if you see a big H, because ultraviolet rays from the sun heat the earth, and with clear skies that come with high pressure, the sand and your skin can get very hot.
A hot day at the beach can be relieved by a slight breeze that comes off the water. A seabreeze occurs when warm air and relatively calm wind meet. During the day, the sun heats the land through conduction. The air above the land warms in a process called convection. As the air warms and expands, this causes lower pressure than the cooler, denser air over the water. The lower pressure causes the air to rise and the air over the water flows towards the land. This creates a seabreeze with winds coming from the water.
Oh, how refreshing a seabreeze can be on a hot day! The sun’s rays may be hitting you, but the breeze keeps you from being uncomfortable. Just be careful, because even if you aren’t sweating, repeated exposure to direct rays can damage skin. But nobody thinks about skin cancer or eventual wrinkles while at the beach!
At night, the opposite effect occurs, with a breeze flowing to the sea. Because the land has not been heated, the water then is warmer. High pressure forms over the cooler air over the land and flows out towards the water. This wind flow is called a landbreeze. At night, the water may be warmer than the land, but the afternoon seabreeze is the ideal condition for a hot beach day.
However, too much wind can be disruptive. In the aftermath of Hurricane Arthur, beaches along Cape Cod, Massachusetts saw extreme seabreezes and especially cold water. Although the breezes cooled the summer sun’s heat, you could stay in the sand long without your hat flying off or your chair blowing away! Be sure to choose a calm wind day when planning your trip.
While you are enjoying the rays on the sand, you also might fancy a dip in the water. Weather also affects what the waves will be like once you’re in there. The sea is the area where waves are generated by the wind. Height of the wave depends on wind speed, wind duration, water depth, and fetch, the distance the wave generation exits. The longer, faster and the farther the distance, the larger the waves will be. Once the waves have moved away from the generation area, they become swells. Because swells are rounder and smoother, they are ideal for surfing. Swells used for surfing usually form along reefs, like in Hawaii, where the waves are large and break off-shore. Flat beaches, where the waves break where you stand on-shore, are usually deep as you go outward.
Depending on if you go into the water, and what you like to do in the water, the wind can decide how your beach day will turn out. Regardless, wind and breezes will augment your magazine as you fan yourself on the sand. Clear skies, calm wind, warm land, cooler water, a slight seabreeze and sufficient swells can produce a picture perfect beach day. Of course, this ideal weather all starts with just the right temperature and pressure.