Longshore winds, onshore winds, king tides and rip currents become commons terms you hear when you live at the beach. Tides can effect simple things like when you would like to go for a walk or run on the beach or very important things like flooding and coastal erosion.
What is a Tide and Tidal Range?
Tides are simply the rising and falling of the ocean that typically occurs twice each day. Each day typically has two high tides and two low tides. Each high tide is roughly 12 hours apart and each low tide is about 12 hours apart.
The high tides and low tides are also dependent on your location. For example, the time of high tide in Pawleys Island will be close but at a slightly different time than the high tide in Garden City Beach. The tidal creeks in Cherry Grove, Garden City Beach/Murrells Inlet and Pawleys Island are also effected by the rise and fall of the tides.
The gravitational pull of the Moon, Sun and Earth cause tides to rise and fall. However, the Moon has more effect on the tides because the Moon has a stronger gravitational pull. The tidal range refers to the difference in height from the high tide point to the low tide point.
King Tide…What is It?
If you live at the beach or have visited the beach during a full moon, you may have noticed the high tide is higher than normal and the low tide is lower than normal. The same thing happens during new moons (when the moon is dark). This phenomena is called a spring tide and typically occurs twice during a month. Contrary to how the name sounds, spring tides do not refer to the spring time of the year. Spring tides happen anytime there is a full or new moon. These tides are named spring tides because the tides are “springing forth”.
Extreme spring tides are commonly called a king tide. Scientifically, these extreme high tides, called perigean spring tides, occur about every 28 days when the moon is at its perigee (when the Moon is the closest to the Earth and the gravitational pull of the Moon is at its strongest). The tidal range is also wider during a king tide – meaning there is a greater distance between the height of the high tide point and the low tide point than there normally is.
King Tides and Coastal Flooding
The effects of king tides vary anywhere from hardly noticeable to coastal flooding. King tides do not always cause coastal flooding and do not cause coastal flooding everywhere. Onshore winds, a coastal storm or heavy rain that happen at the same time as a king tide typically cause flooding.
Coastal flooding occurs most often in low-lying areas. We see coastal flooding in our area most often in Cherry Grove in North Myrtle Beach, parts of Garden City Beach and Pawleys Island. King tides also effect tidal creeks…Cherry Grove, Garden City Beach and Pawleys Island.
2021 Predicted King Tides
King tides are predicted to occur two more times in 2021. Those higher than normal tides will likely occur November 4-8 and December 3-7.
Previous king tides for 2021 were during the following days…
- April 26-29
- May 24-28
- June 22-25
- July 22-24
- October 7-10
Where To Find Information on Tides
NOAA (National Oceanic and Atmospheric Administration) publishes high and low tide times for different stations around the US. SCDHEC also publishes tide information and a tide chart each year. I like the chart because it does show the moon cycles along with the predicted king tide times. However, the tide chart is based off tide times in Charleston. You can find the time correction for different areas towards the bottom of the 2021 Tide Tables page.
To get more specific tides for the beach or tidal creek nearest you, several tide charts are available online or download an app for your phone (there are many choices for both so take a look at several until you find one you like). I use the Tide Charts app on my phone (it is available for iPhones and Androids).
I reviewed several webpages to get information for this post. Below are some websites that you can read if you would like more in-depth information on tides and king tides.
- What is a King Tide?
- What are Spring and Neap Tides?
- What is a Perigean Spring Tide?
- NOAA High Tide Bulletin
- Tide Table for Garden City Beach Pier (and other information)
- 2021 Tide Tables
- King Tides – You Can Help
Our local news stations and meteorologists tell us when king tides are expected in our area. Here are links to the local news stations…
Knowing about tides and coastal flooding that can occur during a king tide is important when living at the beach. I hope you were able to learn more about king tides and their possible effect on our beaches.
See you around town!