Low snow

Those who live in California or have followed news about our weather recently will know that we have had an epic rain and snow season–quite unexpected. One of the storms brought shockingly low snow levels in the Bay Area and surroundings on the night of 23-24 Feb. I took some photos from the finca and nearby.

The first picture, above, is taken from the back of the property with my telephoto. This is looking roughly due east. The next two are views slightly to the south of the first one. Wherever you looked, you saw low snow!

(Click any photo to load a larger version.) Next we shift the view from the back to the road side of the property, looking southwest in the general direction of the Berryessa Gap.

Then I went and took a short drive, finding a location where two roads meet near an overpass on the I-505 freeway, affording a view from a relatively high point. The view from here is especially striking because the almond trees were near their full bloom at the time.

We have lived at this current location for ten years now, and have never seen the slightest dusting of snow even at the top of these hills, which form the first range of hills separating the Sacramento Valley from the Capay, Napa, and other valleys farther west. Locals say there was maybe one other time about twenty years ago when there was snow on these hills, but not nearly this much. And about thirty years ago there was snowfall actually at the Valley floor where we are. That would be extremely unlikely to happen again. These synoptic conditions were probably similar to that storm, but in a significantly warmed climate. I believe I saw some snow flurries here right around sunrise, and some very nearby weather stations were reporting rain/snow mix at the time. The snow on the hills stuck for a couple of days, but was all gone before long as conditions warmed and more rain fell.

(Note: the blog’s banner photo is towards the northeast, looking at the Sierra, much farther away. Seeing snow in that direction is obviously not rare in the winter. That picture is from several years ago.)

Smoke and chill

We have been dealing with heavy smoke from the Camp Fire in Butte County, which is a couple hours’ drive north of us. The weather conditions have been such that the smoke has settled and some days it has been like a fog that starts out moderately thick and never totally clears.

What I did not expect was that it would be so cold during this smoky phase. The fire began on 8 November, and the winds that initially made the fire so devastating died down late in the day on the 11th. Since then, we have had six straight mornings with low temperatures at 36F or lower, including three at 32 and two more at 33. This is substantially colder than the norm for this time of year. Usually–at least in the years I have been at this location–we do not get a morning below 32 until some time in December.

The NWS forecast discussion last night mentioned, “The smoke is keeping temperatures below normal blocking heating from the sun during the day and allowing heat to escape at night, unlike cloud cover.”

It is obvious that smoke cover would keep daytime highs down. In fact, we have not had a high temperature higher than 66 for the past six days, and some days have been only 62 or 63. That is near or a little below the norm for mid-November. (Normal low and high temperatures for the month of November around here would be more like 41 and 66.)

I would not have expected smoke to help keep it so cool overnight. Perhaps naively, I would have expected it to act more like cloud cover. Evidently, however, the fire has had the effect of getting our winter-chilling off to an early start. The deciduous trees are presumably dormant enough by now to “receive” chill, so this early cold snap is a good start.

The fire has been one of the worst disasters in the state in some time, and the air quality has resulted in UC Davis being shut down since 12 November and through the upcoming Thanksgiving holiday. Through all the awfulness, these cold mornings have been welcome.

Temperature means, winter months, 2013-18

By popular demand*, here’s a full accounting of our winter temperatures since moving to the current location.

The stats really drive home just what an unusual winter this was, with the colder temperatures very much concentrated towards the latter part. I discussed the consequences of this for the deciduous fruit tree blooms in an earlier “planting“.

February’s mean low was more than four degrees below the five-year mean, and the March high and low were both 3-4 degrees below the five-year means.

December was also colder than normal, in terms of overnight lows although the daytime highs were the warmest experienced in a December thus far. The December cold was not as far below norm as we experienced our first winter here, 2013-14, when an extreme freeze was very costly to some of my citrus and other subtropical trees. Even the Eucs had damage that winter.

* Not really, I must admit.

Spring 2018. Or is it winter?

Sometimes in a climate like this one, the seasons kind of mash together. It was an unusually warm January, and some trees are in bloom now. Yet this morning the temperature was 30F and there were ice crystals on the grass.

First blossom one one of our almond trees–8 Feb.

The Flavor Delight aprium is in bloom, 11 Feb.

The blooming is not early, despite the January warmth. The almond depicted above usually has its first bloom around the same date in February: the 12th in 2017, 6th in 2016, 3rd in 2015. The Flavor Delight likewise tends to have its first several blossoms open around now: 14th in 2017,  7th in 2016, 15th in 2015.

What is somewhat more unusual is below-freezing temperatures at this time of year. (I am sure they were common at this point in February decades ago, but not recently.) The latest date of a below-freezing temperature in 2017 was 25 Dec. (29F, though it was 32 on 24 Feb.), in 2016 2 Jan., in 2015 3 Jan, and in 2014 5 Feb. And the current forecast calls for a few days of low temperatures in the 20s and 30s. This could be bad for pollination of the trees in bloom and for tender young leaf growth on the citrus and some other trees.

That is the nature of a Mediterranean climate–“spring” begins in early February, but winter can keep hanging on.

Fog and chill

It has been foggy in recent days. Far from my favorite kind of weather, especially when it sticks around all day.

Sometimes, however, it can be good for the chilling hours accumulation that the deciduous fruit trees need. It is the tendency towards multi-day dense fog events that has made the San Joaquin Valley (south of here) historically a good place for prunes, peaches, apricots, and other fruits that need winter chill to set well in the subsequent growing season.

However, this has been the case with this fog event only on one day, when we had a low of 39F and, due to the fog, the temperature did not reach 50 till after 10:00 a.m. Prime chilling temperatures are roughly 38 to 45, with some continuing but significantly diminishing value up to the lower 50s. So that day was a good chill day.

Not so much since. For the past two days, the temperature has just hovered in the 45-51 range. That’s pretty close to useless.

(I had been meaning to write about the fog and chill even before I saw that a reader had commented at a post that is almost 12 years old, with a question about chill. One of the things I always appreciate on this blog is people commenting on old threads. I almost never close comments, no matter how old the thread, unlike some other blogs out there.)

Yes we have had some rain

After years of little more than an occasional storm, we had quite a series of storms, and they were big ones. The Sacramento River is mighty once again!

The view is from Old River Road, which is usually high above the water level. So are those houses. Now they are really riverfront properties in a perhaps overly literal way.

The river does not flood its banks, however, due to a remarkable piece of 1916 engineering called the Sacramento Weir and its manually operated gates. Last week was the first time this had been opened in over a decade.

(short video; click to open in a new window and play)

That is Old River Road running over the Weir, and parallel to it, the Sierra Northern Railway.

When the river reaches a certain level, the gates of the Weir are open and the overflow spills into the vast tract of low land known as the Yolo Bypass.

The levees around the river and the bypass protect not only houses, but farmland. For instance, this recently planted nut grove (walnuts, probably) that is directly across Levee Road from the bypass.

Below is a photo of the Sacramento River looking upstream. Those trees are growing on the steep bank of the normally dry levee.

The Sierra Northern crosses another section of the bypass that is fed by a weir farther upstream. Here it is on a trestle that is normally high above the wetlands. A road runs through there, but at ground level, which is, for now, now well below water level. (View from the I-5 causeway.)

 

 

 

 

Interesting cloud feature today

It’s been a mostly cloudy day. But really, only here. Most of the Central Valley and northern California region has actually been clear. This narrow cloud band has been parked over our area almost all day.

(Screen shot from NWS satellite image)

Here is what it looks like from ground level.

With the help of the satellite image, I can now be certain that the straight line direction down the middle of this cloud band is looking more or less right at Marin County. At the tiome that I took the photo (around noon), the band was crossing the shore just between Point Reyes and the Golden Gate. It has been slowly creeping southward, but very slowly. We are now (almost 3:00 p.m.) just under the band’s northern edge, and a re-check of the satellite imagery shows it is crossing the shore directly over the Golden Gate–and also even narrower.

Underneath it here, the temperature has been in the lower/mid 80s, a welcome relief from the 100+ temperatures we had earlier in the week. The fruit trees are certainly a lot less stressed today.

The first big storm

We have been at our current location for about twenty months. There has not exactly been a lot of rain during that time. Till yesterday. It rained from early in the morning till late at night, sometimes heavily, amounting to around three and a half inches. It brought our total to the month to 5.7, whereas from 1 July to 31 October we had had only 2.3. And the 6-10 day outlook says more is probably on the way!

So we finally see how well the property drains, or to what extent we get standing water. Early returns are favorable. It drains just fine, and there is no water standing in the one completely flat area where I put in some fruit trees.

Apple trees, among others; the branches on the ground were put there by me. I pruned them the day before to reduce the “sail” effect, given forecast very high winds (which were less than feared).

There is not even the slightest water standing at the bottom of the big hole where a former owner attempted to put in a pond. Now we see why he had no luck!

View towards the north

There is just a little bit of standing water in our pasture, visible beyond the Eucalyptus near the center of the image. Just over the fence, however, the neighbor has quite a nice little lake. When I was out there earlier, I could hear geese honking nearby. And I’ve heard some frogs. They should be quite happy today.

View towards the west/northwest

Snow

I don’t know when it last snowed at this elevation (1500 ft) in San Diego County, but it would have to have been many years.

It’s pretty, but not really the best thing for citrus and avocado trees. Or stone-fruit trees that are already in bloom. (That’s the Mesch Mesch Amrah plumcot in between the mandarin and the avos.)

Here it is as it was falling last night, around 9:30 p.m.:

Many more photos at the Flickr site.

Snow?

The forecast says the snow level will drop to as low as 2000 feet Saturday evening, locally 1000. We are at 1500.

It has been a really cold week, by local standards, especially for late February.

Too bad all this chill is basically useless for the deciduous fruit trees, coming this late. We surpassed 500 chill hours earlier this month. However, we really won’t get more useful chill, as almost everything is leafing out or blooming by now. And getting snow, or freezing temperatures on the buds and blooms is not a good thing.

But some snow would certainly be interesting…

It rained a bit

Thursday, early in the morning, one of the most incredible storms this region has seen finally moved out. We had 6.25 inches in just over six days, 2.76 of which fell on Wednesday; many areas to the north had a good deal more.

It rained heavily enough for a time on Wednesday that we had a little river running through the property, not to be deterred by fresh prunings off one of the apple trees (which has several varieties that were grafted on to it last spring).

The main event of the rain lasted about 72.5 hours. During that time, only near the end were there as many as five straight half-hour increments (the archive time on my weather data-logger) in which no rain was recorded. At one time on 20-21 December, rain was recorded in 42 consecutive half-hour periods. That was part of a run of 123 of 132 half-hour periods in which rain was recorded. So, it rained rather persistently.

I can recall some phases of rain over a week or so long in the past that were impressive. As recently as January of 2010, for example. And no one who lived in Southern California at the time will forget “epic” rainy periods in 1983 and 1969. But usually these involve a series of discrete heavy storms, punctuated by several hours of some sunshine and no rain. This time, as the stats above reveal, it just kept raining. And raining. There were not even any breaks in the clouds, at least during daylight hours (and the record suggests not at night, either) from Saturday afternoon till Wednesday afternoon.

Today it was sunny and relatively warm (first time over 60 since 14 Dec.). But more rain is forecast for Saturday night and at some point during the coming week.

It’s a bit saturated around here.

We won’t have to irrigate for a while. And, thanks to that cold snap in late November, and more than a week of cool days (albeit fairly warm nights for the time of year) during the rain, we are almost to 250 chill hours already, which is good for the stone fruits.

Signs of the season

In late November, we had a couple of mornings with temperatures just below freezing.

This photo shows a hedge with some frost damage a few days later (3 Dec.), along with two other signs of the season: a Hachiya persimmon laden with fruit, and a navel orange tree with fruit just starting to color up. (The orange also shows the results of some major limb breakage from fruit weight and high winds back in October; yes that’s one orange tree).

Fall/winter season is well underway.

The most recent evidence of that is four straight days of essentially uninterrupted rain.

Some more seasonal shots (all from late November or early December):

Still more…

Colorful cloud

An hour or so before sunset, this colorful cloud appeared in the southwestern sky. When I first noticed it out my window, I thought I was just getting some sort of light effect from the dual-paned widow itself. But it looked that way from outside, too. At least around these parts, this is an unusual sight.

Yesterday we had heavy wind (gust here up to 35, which is rare, but other areas nearby had much stronger) and quite a bit of rain (1.4 inches here, more elsewhere). Today very chilly, by local standards (high 55F). More rain coming in the next few days, and likely a cold night tonight. Winter is here.

Changes

It must be fall. It was 68 today. First day with a high below 70 since 10 June. And what’s that? It might rain this week? Bring on the rainy season!

Normal

Yesterday I looked out the window at about six in the morning and saw an unusual reflection. What was it? Oh, morning sun–the first time in nearly six weeks that there had been actual sunshine at sunrise.

Today things have returned to normal.

View to the east of the finca, 8:40 a.m., 17 June 2009