Watching Oroville as Storm Approaches

A graphic depicting California-Nevada River Forecast Center precipitation outlook for Feather River basin above Lake Oroville (the reservoir is at lower left, just upstream from the town of Oroville). White shading indicates areas forecast to receive more than 7 inches of rain between Thursday and Sunday morning. (Click to expand image.)

Not so long ago — through late February, say — the news about California’s “wet” season was how dry it had been. But that changed last month, when a series of late-season storms pulled the state back from the brink of a return to deep drought.

As the last March storm departed, I heard people asking, “Is that it? No more storms?”

But model-watchers saw a return to wet weather late this week, and those supercomputer prognostications have been borne out in the form of a very warm, very wet storm that is forecast to dump huge volumes of water over the northern two-thirds of the state.

One of the regions forecast to get the heaviest deluge is the Feather River watershed, above Oroville Dam and Lake Oroville. That’s news because the California Department of Water Resources, which owns and operates the dam, may be forced sometime in the next few days to release water down the dam’s half-completed spillway.

The image above is from the California-Nevada River Forecast Center, and it depicts a precipitation forecast for more than 7 inches of rain in parts of the Feather watershed over the next 72 hours. (There’s an interactive version of the map on the CNRFC site, here.) DWR has, without a doubt, modeled the expected runoff from that much rain falling so quickly, how fast the lake will rise, and when it will reach the “target” elevation at which the spillway gates will open and water will flow down the 3,000-foot-long concrete chute.

As of this morning, the reservoir is about 20 feet below the lip of the spillway inlet and about 37 feet below the target elevation of 830 feet above sea level. From outside, it’s hard to guess how quickly the lake might rise — that’s a function of the total precipitation, how saturated soils in the watershed are, how much snow might melt off in the watershed’s upper reaches, and how much water is released from the reservoir through the only currently available outlet, the dam’s hydroelectric plant. But given the rate of the lake’s rise during the last round of heavy rain, it would appear that it would be late next week before that 830 foot threshold is reached.

Here’s the current DWR statement on reservoir conditions and prospects for a spillway release.

Today It Rained

Flowering quince, just up the block from the old Adams place.

Today it rained. Those droplets on the flowering quince up there above are the proof. Our non-fancy rain electronic rain gauge reads .04 of an inch for the day. And since this was the first rain since January 25, that makes .04 of an inch for the month, too.

As California climatologists are quick to point out, longish dry spells are not unusual during California’s wet season. But this long dry spell matches one we had in December, when we got just .12 of an inch. Those two dry months came sandwiched around a pretty average January — 4.77 inches according to our rain gauge. So adding up the last two and a two-thirds months, we’ve gotten less than 5 inches of rain, total.

As in most of the rest of California, December, January and February are the three wettest months of the year. The official Berkeley record shows an average total for those three months, since 1893, of 13.16 inches. The December-January-February average for the 1981-2010 climate “normal” was significantly higher — 15.23 inches. (That’s a pretty wide spread, and it’s probably due to many months of missing data over the last 125 years.)

A year ago — our one really wet winter in the last six, we got 9.85 inches in February alone. Our D-J-F total for 2016-17 was 28.63 inches.

Of course, February isn’t over yet. More chances of rain are forecast over parts of Northern California for the next week. We’ll see how that pans out.

One of Those Nights

It’s 11 p.m., and the temperature is 71 here in Berkeley.

That late-night warmth in mid-June would not be news in Chicagoland, where I grew up (the current temperature at Midway Airport, recorded at midnight CDT, is 78) or most of the rest of the country outside of the Pacific Northwest.

But here, 71 degrees as we move toward midnight is unusual; and reminiscent, though we don’t have midwestern humidity, of growing up in Chicago’s south suburbs.

Somehow, my parents grew up without air conditioning. We didn’t have it, either, in our house on the edge of Park Forest. It seemed impossible to sleep on really warm, humid nights, though I’m probably forgetting that fans helped.

Our dad would go to bed early; our mom was a night owl and would have some late-night TV on. Johnny Carson, maybe, or “The Late Show” movie. She’d let us stay up if it was too hot to sleep. If the night was oppressive and sticky, she’d have us take a cold shower to cool off.

Thinking back, Mom didn’t get her driver’s license until after our last summer in Park Forest. The next June — 1966, when I was 12 — we moved out to a new house built on an acre lot in the middle of the woods we had lived across the street from. It was like a jungle out there in the summer — green and moist and full of mosquitoes and lots of other wildlife.

Things changed once we moved out there. We had air conditioning. One unit upstairs, one downstairs. Outside, it might be dripping. Inside, it was miraculously cool and dry — a different world. I imagine the electric bills were staggering compared to what they had been at our old place.

Then, too, Mom had her license. Every once in a while, she’d invite us out on a late-evening jaunt — to the grocery store, or just to drive.

An Eye on the Eye of the Storm

Himawari satellite image of an intense storm in the northern Pacific, March 26, 2016.
Himawari satellite image of an intense storm in the northern Pacific, March 26, 2016.

A few weeks ago, I downloaded a Chrome browser extension that, when you open a new tab, shows a current (or at least very recent) view of the full disk of the Earth as captured by Japan’s geostationary Himawari 8 weather satellite. Himawari produces high-resolution images of the Earth — the kind you can lose yourself in for hours if that’s the kind of thing you like.

Anyway, I noticed last Friday and Saturday that the full-disk image was showing a huge storm someplace in the northeastern Pacific. I wondered whether I could find a better view of the images online, and sure enough, NOAA’s Regional and Mesoscale Meteorology Branch (RAMMB to its friends), which inventories a lot of satellite images, features a Himawari Loop of the Day.

The loop for Saturday, March 26, was titled “Intense Low in the North Pacific.” Hit that link and it takes you to a movie — you need to have a little patience for the download — of the storm I was seeing in the full-disk picture. The image above is a frame from the movie.

It’s extraordinary. Or maybe everything on Earth is extraordinary if you have a chance to sit back and watch it for a while.(One note on the movie: A shadow crosses toward the end: that’s night falling as the Earth rotates. But the surface details are still visible because of GeoColor, a system that blends visible (daytime) and infrared (nighttime) imagery. GeoColor is also responsible for the reddish appearance of cloud tops in the nighttime images.)

Below is what the storm looked like on a conventional surface weather map: a sprawling, intense system with sustained winds over 60 mph forecast to occur 500 miles and more to the south and southwest of its center. The storm was producing monstrous waves, too, with seas as high 34 feet.

stormchart

The Control of Nature: Primitive Hydraulics

Sunday morning: Still raining.

We’ve had .42 of an inch so far today (it’s 1:30 p.m. daylight-saving style) to go with the 6.48 over the past nine days.
The rain has prompted me to return to an old wet-weather routine that Kate and I have called, in a nod to a favorite writer and a favorite series of articles in The New Yorker, “the control of nature.”

When we moved into our house in April 1988, it was noted in some document somewhere that there was a sump pump on the premises. I found out where the pump was and why it was there the following winter.

Our house has a crawl space. Our lot is on a slope paralleling the course of Schoolhouse Creek. The stream itself has been moved underground, but as we found out one very wet December day a little more than 10 years ago, too much water arriving all at once can, along with a clogged storm drain upstream, bring the creek back above ground.

Water appears less dramatically in our crawl space, and that’s why there’s a sump pump down there.

Usually, a murky pool will gather in a spot that’s been excavated to allow access to the crawl space. Sometimes, as in deluge that arrived early the morning of New Year’s Day 1997, the space will start to fill. That was the one and only occasional the pump, installed in a little concrete well built around our floor furnace to keep the heater from getting flooded, turned on.

Perhaps one reason the pump hasn’t been more active is because I try to keep the crawl space drained when I see water gathering there.

Control of nature requires gravity and a garden hose. I take the full hose, stick one end of it into the watery crawl space. Then I run the hose down the driveway — 30 to 40 linear feet and 3 to 4 vertical feet — to the street.

I set the hose running last night about 9 o’clock. It’s still running. How much water has come out of there in that time?

I tried to calculate the rate by measuring the flow into a 1-cup measure (yes — this has the possibility of introducing a large error; but let’s just agree I’m not being perfectly scientific). In four trials, the cup filled up in about 6 to 7 seconds. Based on that, I figure somewhere between 32 and 38 gallons are draining out every hour. And that would put the total for the 15 hours or so the thing has been running at 480 to 570 gallons. Which is more than I would have guessed.

Berkeley Rainfall: Six and a Half Inches in Nine Days

While I’m poring over state and federal databases and pondering what it would be like to live through a year with 145.9 inches of rain (Cooskie Mountain, in the King Range of southern Humboldt County, in 2006) or a month with 43 inches of rain (Gasquet Ranger Station, on the Smith River in Del Norte County, December 1996) or 42 inches in nine days (yes, it happened: Bucks Lake, Plumas County, in January-December ’96-’97), let me record what we have actually seen here in Berkeley the last week or so:

Friday, March 4: .46 inches
Saturday, March 5: 2.61 inches
Sunday, March 6: .50 inches
Monday, March 7: .46 inches
Tuesday, March 8: 0
Wednesday, March 9: .13 inches
Thursday, March 10: .87 inches

Friday, March 11: .46 inches
Saturday, March 12: .99 inches (and counting)

That’s a total of 6.48 inches in nine days, as recorded on our cheap, semi-dependable (it’s very close to neighboring totals reported on Weather Underground) Oregon Scientific wireless rain monitor.
A pretty rainy spell, the rainiest this winter by far.

Rain

storm151101.jpeg

Above: From NASA’s Worldview site, an image of California’s first real storm of the wet season (click for a larger version, or check it out on Worldvew). Here’s (a slightly edited version of) how the National Weather Service’s San Francisco Bay Area forecast office described the weather system as it was shaping up early Sunday:

AS OF 09:59 AM PST SUNDAY...NORTH AND CENTRAL
CALIFORNIA ARE CURRENTLY POSITIONED IN THE BOUNDARY
BETWEEN TWO LARGE FEATURES. TO THE SOUTH...THE
HIGH PRESSURE THAT HELPED TO BRING CLEAR SKIES AND UNSEASONABLY
WARM TEMPERATURES OVER THE PREVIOUS FEW DAYS. TO THE NORTH...AN
APPROACHING STORM SYSTEM WITH A POTENT MOISTURE TAP. A COLD
FRONTAL BOUNDARY IS SEPARATING THESE TWO AIR MASSES AND IS EVIDENT
ON BOTH RADAR AND SATELLITE FROM THE THICK BAND OF CLOUDS AND
CONTINUOUS RAINFALL REFLECTIVITIES ASSOCIATED WITH IT. THIS
FRONTAL BOUNDARY IS CURRENTLY DRAPED FROM NORTHWESTERN CALIFORNIA
THROUGH SOUTHEASTERN OREGON AND HAS BROUGHT UP TO 2.5" OF RAIN
ALONG THE HIGHER TERRAIN OF THE OREGON COAST AND UP TO 2" OVER THE
HIGHER TERRAIN OF THE NORTHWESTERN CALIFORNIA COAST. THESE HIGHER
VALUES ARE SUPPORTED BY A TROPICAL pMOISTURE PLUME WITH PRECIPITABLE WATER VALUES
RANGING FROM 1.2"-1.6" WHICH ARE 150-200 PERCENT WETTER THAN NORMAL.
LOWER ELEVATION LOCATIONS IN THESE AREAS HAVE NOT PICKED UP NEARLY
AS MUCH... RANGING FROM SEVERAL HUNDREDTHS TO A FEW TENTHS. WE
WILL LIKELY SEE SIMILAR ELEVATION BASED PRECIP SCALING FROM THE
FRONT AS IT MOVES THROUGH OUR AREA THIS AFTERNOON AND INTO EARLY
MONDAY.

The rain started here in Berkeley about 9 p.m. or so. It’s been more than a drizzle: .29 of an inch in the last couple of hours, on the off chance that the backyard rain gauge (which I got just after the last rain of the spring) is correct. That seems to line up with other rain gauges around town that report on Weather Underground. We’ll see how accurate it looks tomorrow.

A July Surprise: Actual Rain

The fact it’s July notwithstanding, the National Weather Service forecast rain for Thursday. Our seasonal but only faintly known monsoon — it occasionally brings heavy rain to the Sierra and other ranges but rarely visits the lowlands with rain — has been potent this year. Despite that, it was a surprise when rain began pattering on the roof early this afternoon. And just as surprising when showers started up again about nightfall.

How much did it add up to? Our rain gauge, which has gotten very little use since we set it up in the spring, recorded .05 of an inch. Other weather stations around town — I find it hard to find the “official” reading here — recorded up to about .10.

Checking the Western Regional Climate Center records for Berkeley, it appears the official record for the date here was .10, in 1974. The average monthly July rainfall for Berkeley, in records that go back (though with some gaps) to 1893, is .03 of an inch.

And the wettest July day ever recorded in Berkeley is actually kind of surprising: 1.40 inches, on July 8, 1974. That was part of a storm that swept the region and yes, made headlines. Here’s the front-page portion of a story from the Marin Independent Journal (and below that, the PDF of the entire front page, which features a six-column picture of a flooded U.S. 101 in Corte Madera as well as some better-known history):

Screenshot 2015-07-10 00.58.36.png

Daily_Independent_Journal_Mon__Jul_8__1974_.pdf

Frontyard Visitor: The Gulf Fritillary

gulffritillary141123.jpg

Wednesday it rained. Thursday it rained. Saturday, it rained again.

Right there’s some news. Even though the rain didn’t amount to much — I’d guess just an inch or so here in Berkeley for all three “storms” — that was the most concentrated precipitation we’ve had since April, I’d guess. Today (Sunday) was clear, and that after avoiding even looking at the yard for a long time — the front “lawn” has not been watered in several seasons and looks worse than dead — I thought I’d taken advantage of the warm, dry weather and clean things up a little.

One of my chores was to cut down the mostly dead stalks of our September-blooming sunflowers (Helianthus salicifolius). I did that, then picked up the whole bundle of stalks to stuff in our green can (the one for “yard waste). As I started to push the stuff into the can, I realized there was a beautiful orange butterfly tangled up in the mass of dead stems and leaves. I thought it was dead, but then it moved. So I pulled stalks out of the can to give it more space to wriggle free. It quickly extricated itself. I ran for my camera, but it flew before I could get a shot.

I ran and grabbed my camera and followed it for a few minutes down the block. The undersides of the butterfly’s wings are gorgeous — “spangled in iridescent silver,” as one description I found puts it. I couldn’t manage to get a clear shot of the undersides, though.

Kate went online to make the identification: a Gulf fritillary (Agraulis vanillae). The Bay Area is about as far north as these get in California, though they have been seen recently in the Davis and Sacramento areas. Here are a couple links with details:

The name “Gulf fritillary”: Well, “Gulf” comes from their association with areas bordering the Gulf of Mexico. And “fritillary”? A U.S. Forest Service “pollinator of the month” page explains:

The common name comes from a Latin word, fritillus, which means chessboard or dice box. Fritillary is also the name of a flower with an interesting checkered pattern; it is obvious that both the flower and the butterfly get their common name because of such pattern. Another name for these handsome butterflies is silverspots because of the metallic markings on their wings undersides. It is possible that this pattern, similar to a leopard’s spots, serves as camouflage when they are resting in places of dappled sun and shade spots.

Getting in further over my head: It should be noted that the Gulf fritillary is a member of the same butterfly subfamily, Nymphalidae (brush-footed butterflies) but a different tribe (Heliconiini) from the rest of the fritillaries (Argynnini). I didn’t know butterflies had tribes. And that’s as far as I’m going to take the fritillary story for this evening.

Slideshow: Lake Oroville, Before and After

Thanks to the miracles of software and the Internet, I put together a short slideshow comparing scenes at Lake Oroville as I shot them late last March and yesterday. If I’d known back then to what extent the lake would empty out, I would have taken pictures all along the shoreline. As it was, the pictures I did take of the lake were an afterthought, something to do before we started to head home.

The big surprise in the “after” pictures, the ones I took yesterday, is the landscape revealed by the receding waters. There’s no hint looking at the surface in March what the underwater topography looks like. And it’s amazing looking at the exposed landscape now (it was drowned in 1969, when the new reservoir was first filled) and how completely it’s been scoured of anything that might suggest that before Oroville Dam was built, these were canyons choked with oak, pine and brush.

Here’s the slideshow which includes a few bonus shots at the end):