A perfect combination of cosmic events will occur this holiday season to bring astronomically high tides known as king tides to San Diego just before Christmas, forecasters say.
The phenomenon, which describes what are typically some of the highest tides of the year, are scheduled to occur on Dec. 23 and 24. A second round is predicted to happen on Jan. 21 and 22.
The National Oceanic and Atmospheric Administration (NOAA) predicts that this winter season's tides may cause coastal flooding in low-lying areas of San Diego.
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Here's what to know:
What is a king tide?
A king tide is an informal name for exceptionally high tides known as spring tides, which are caused by a stronger-than-normal gravitational pull from the moon and sun.
While high tides occur twice a day, king tides occur only a few times a year when a new or full moon is closest to Earth during specific seasons. On the West Coast, they typically occur during the summer and winter solstice, which is on Dec. 21, according to NOAA.
An increase in the gravitational pull can be caused by different reasons, but in the case of this year's Christmas king tides, a supermoon will be occurring. A supermoon is when a full or new moon occurs at the moon's perigee -- its closest distance -- to Earth.
That's expected to happen at about 2:17 a.m. on Dec. 23 for San Diego.
San Diego Weather
BONUS! Since the supermoon is a new moon, it won't be visible from Earth. But you may be able to catch the Ursids meteor shower in the exceptionally dark skies. The meteor shower is active for about a week in December and is expected to peak early on Dec. 23.
Other causes for even higher king tides could be storm surges or an El Nino event, which warms and expands ocean waters. Neither are predicted to occur during these next king tides.
When can I see the king tides?
San Diego has several stations that report tides to NOAA. Here are the tide predictions from the Scripps Institution of Oceanography reporting station at the Scripps Pier in La Jolla:
| Date/Time | Time | High/Low, Height |
|---|---|---|
| Friday, Dec. 23, 2022 | 8:08 AM | high, 6.95 ft |
| Friday, Dec. 23, 2022 | 3:33 PM | low, -1.76 ft |
| Saturday, Dec. 24, 2022 | 8:54 AM | high, 6.94 ft |
| Saturday, Dec. 24, 2022 | 4:20 PM | low, -1.75 ft |
| Saturday, Jan. 21, 2023 | 8:03 AM | high, 6.96 ft |
| Saturday, Jan. 21, 2023 | 3:21 PM | low, -1.99 ft |
| Sunday, Jan. 22, 2023 | 8:50 AM | high, 6.93 ft |
| Sunday, Jan. 22, 2023 | 4:02 PM | low, -1.89 ft |
Check tide predictions for other parts of San Diego County by clicking here and selecting a reporting station closest to you.
Note that while king tides are known for being exceptionally high, it is low tides that may provide the best opportunity for beachgoers. During these even lower tides, it may be possible to see even more creatures in tidepools and along the shoreline.
Are king tides dangerous?
King tides are predictable but they are often high enough to cause beach erosion, street flooding and flooding of some homes or businesses that are close enough to the coast. In the past, the very high tide has caused flooding in places like Imperial Beach and La Jolla Shores.
While king tides are not caused by sea-level rise, they can give "us an idea moving forward in time what future tide levels could look like as our sea levels are rising," NBC 7 Meteorologist Sheena Parveen said. The City of San Diego is projected to see a rise between 1.2 and 2.8 feet by 2050.
The California King Tides Project, organized by the California Coastal Commission, asks citizen volunteers to document the changing tides, particularly during king tides. Citizen scientists up and down the California coast upload their videos and photos to help the state keep track of the changing coastline. To get involved, click here.
