Tide Levels and Storms
Tide levels can vary significantly depending on the time of day and weather. Some tides can be extremely high, while others can be very low. These changes in sea level are caused by the combined gravitational forces of the moon and sun. The tides are also affected by wind and barometric pressure changes. They can be used to predict the tides, but are not accurate in all cases. Those living along the coast should take note of the tides and their predicted range and use them to assess risks.
In coastal areas, the highest tides are generally at new or full moons. This is because the gravity of the moon and sun are aligned. However, other astronomical factors can affect the tides, including the Earth’s rotation, the Sun’s orbit and the Moon’s position. It’s important to check the tidal predictions before traveling to a shoreline.
In North Carolina, the difference between the highest and lowest tide levels usually hovers around three feet. If the difference between the highest and lowest tides differs by more than a foot, this may indicate a change in wind or atmospheric pressure. Winds can affect the water level more than lunar tides, especially in Pamlico Sound.
While the tides are most important to those living near the coast, they can also affect people who are inland. For example, the highest tides during a storm can bring flooding, especially in low-lying coastal communities. A storm can also bring a storm surge, which is higher than the sea level at the shore. Storm surges are a result of piling up of water from the deep ocean onto the shore. When the water comes ashore, it carries sand and other materials seaward, causing minor street flooding and rough surf.
Although some of these changes are caused by the wind and the barometric pressure, the tides are the major source of short-term changes in sea level. Usually, the largest changes happen during large storms. Depending on the weather conditions, a hurricane or a non-tropical storm can cause a surge or a tsunami. During these events, the level of the water can increase by up to 20 feet. As the storm moves away, the tides continue to rise.
The tides of the Bay of Fundy are among the highest on Earth. This is because the ocean here is far from the continental shelf. That makes it a perfect place to study high-tide levels. The maximum range measured in Burntcoat Head in the Bay of Fundy in November 1998 was 16.3 metres.
High tides are caused by a combination of the lunar gravity and the Earth’s rotational force. The tides are normally two-hour periods, and a new or full moon can cause minor flooding. There are two types of tides, semidiurnal and diurnal. Semidiurnal tides are typical along the East Coast. On the other hand, diurnal tides are more common on the West Coast.
Other causes of change in tides include tidal cycles and seasonal weather patterns. New moon and full moon tides are especially likely to cause flooding, especially in areas that are prone to floods.