Atmospheric River
Started: 2021-12-15 09:39:26
Submitted: 2021-12-15 11:02:41
Visibility: World-readable
Looking out at the roiling ocean in a winter storm
On Sunday it started raining in Santa Cruz, and by Monday the rain had turned into a deluge. I watched the weather radar and weather reports, and I found the Weather Service's nearest stream gauge (on the San Lorenzo river just upstream of Santa Cruz), and during lunch I drove down to East Cliff to watch the waves.
I parked on the bluff on the left bank of the San Lorenzo River, immediately above Seabright Beach. I was not the only person who'd come to look out at the ocean: there were other people walking around in rain coats and struggling against the wind to get their own pictures of the storm.
The pictures here fail to do the scene justice: when I stepped to the edge of the bluff there was a brisk wind blowing straight into my face off the ocean, pelting rain into my face and into my camera lens. The wind was hard enough that it felt hard to breathe when I faced into the wind. With all the rain my camera had trouble figuring out what to autofocus on. The best word I have for the ocean was roiling: huge frothy waves were crashing onto the beach, spraying foam onto the the sand. Above the reach of the water the wind whipped the foam into more waves. The waves looked dirty and angry, and I had no desire to get anywhere closer to the beach than observing it from what I hoped was a safe distance tens of meters away on the bluff.
Immediately to the west the mouth of the San Lorenzo River separated me from Santa Cruz's Main Beach and the Beach Boardwalk. Frothy waves broke along the length of Main Beach in front of the roller coasters and summertime amusements, now shut down for the winter storm.
The San Lorenzo River was running full but well within its banks. I watched logs and branches flow downstream in the muddy chocolate-colored water and empty into the ocean. The nearest monitor upstream showed the river crested at 16 feet, just below the "action" threshold and still a few feet below flood stage. (Further upstream towards Felton several low-lying communities along the banks of the river were placed under an evacuation warning due to flooding combined with debris flow in the scar left by the CZU Lightning Complex fires last summer.) As I drove to the ocean overlook I came face-to-face with the levee forming the river's left bank, towering above the road and dwarfing the pumping station at its base. Most of the time the river remains low enough that the levee was high and dry on both sides, but today the levee was doing its job otherwise the ground I was driving on, and the houses surrounding me, would be underwater.
During the summer, the San Lorenzo River becomes a lagoon, stopping just short of the ocean when its dry-season flow is no longer able to clear the sand deposited at its outlet by the off-shore currents. This problem is apparently exacerbated by the breakwater built on the other end of Seabright Beach to protect the entrance to Santa Cruz Small Craft Harbor; more sand piles up at on the berm in front of the lagoon and as a result the water in the lagoon is higher and less healthy for the fish that try to live in the river over the summer. (My normal morning running route takes me down to the mouth of the San Lorenzo River, giving me a view of the current state of the lagoon. When our first storm breached the lagoon earlier this fall, the water level in the lagoon dropped a couple of feet, leaving behind a noticeable bathtub ring at the old water level.) Santa Cruz has a plan to install a permanent drain to keep the water level lower.
The Weather Service called this an "Atmospheric River", a large storm system blowing in from the Pacific Ocean packed with moisture that turned into rain as soon as it hit land and the Coast Range started squeezing the water out of the clouds.
After a few minutes on the top of the bluff, marveling at the force of the waves breaking on the beach and the wind coming straight in from the ocean, I walked down to the foot bridge crossing the San Lorenzo River immediately next to the rail bridge. The one-block walk along East Cliff Drive to the bridge exposed me to the full force of the storm: by the time I reached the bridge my clothing was soaking wet. (I at least had a good rain coat.) I walked half-way across the foot bridge and squinted at the mouth of the river through the trusses of the rail bridge, with my camera lens covered in rain, before heading back to my car and driving home to change into dry clothes.
I am beginning to appreciate how coastal California handles winter rain: it'll rain consistently for a day or two, and then, just as I'm beginning to think that I've had enough rain, the rain will stop and the sun will come out again. And when the rain does come, it puts on an impressive show.
