This weekend offers a chance to experience extreme high and low tides plus a lunar eclipse. On Sunday (1/20), NOAA predicts a high tide of 7.33 feet at 10:17 a.m. This will repeat on Monday at 11:08 a.m.
These levels are a tenth of an inch higher than the top high tides around the Winter Solstice (7.23) a month ago.
A low tide of minus 1.75 is forecast for Sunday at 5:28 p.m., with an even lower slack of minus 1.83 set for Monday at 6:14 p.m. This compares with a low of “only” minus 1.71 on December 23.
Sunset on Sunday will be at 5:21 p.m., meaning that the nadir on that day should be adequately illuminated for photography. Monday’s sunset is at 5:22, a bit too early to light up the bottom of the low tide, but close enough.
Extreme high tides (“king tides”) on the Berkeley Marina routinely demonstrate the City of Berkeley’s negligence in maintaining its seawall in parts of the Marina. Nothing new there; “Marina” and “mismanagement” is almost a tautology.
Extreme low tides can be more interesting than high tides, as they lay bare acres of mud in the North Basin, offering a vast buffet for shorebirds, and a feast for bird photographers.
Oh, and if that isn’t enough environmental excitement, there’s a double whammy moon event on Sunday night. It’s not only a supermoon, but also a lunar eclipse or “blood moon.” So it’s a “super blood moon.”
The NY Times astronomical editor writes:
During a supermoon, the moon is a bit closer to Earth than usual. In a lunar eclipse, Earth’s shadow falls on the moon, giving it a reddish hue. Sometimes, by astronomical coincidence, the two events occur on the same night, producing a “Super Blood Moon.” Read about supermoons and other moons that are super in their own way, here: http://nyti.ms/2AmXj3h
If the sky is clear, you’ll find me on a hill in the park at around 6:30 p.m., shortly after the low point of the low tide in the North Basin. As happened at the Winter Solstice, the tide and the moon are in a paradox. You know that the moon’s gravity governs the tides, so you’d think that the rise of the moon would mean the peak of the high tide, but just the opposite happens. See my video about the solstice. The eclipse begins at 6:30, becomes total at 8:41, and finishes at 10:40. Here’s more information.