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Precipitation Should Continue Through Winter

Red sky at morning, meteorological warning.

Deciduous foliage gets colorful with autumn chill. Then, it gets messy. Then, with a bit of precipitation, it gets even messier! It seems like a waste as it all succumbs to rain and, in other climates, snow. It is sensible, though. Deciduous vegetation will be less vulnerable to stormy weather without it. Weather will be getting increasingly stormy through autumn.

This is how the Mediterranean climate here operates. The dry season that begins during spring continues until autumn. The relatively shorter rainy season centers around winter. Therefore, most precipitation occurs during winter. Spring and autumn are brief transition seasons that tend to favor the dry season. Almost no precipitation occurs during summer.

Spring and autumn transitions between rainy and dry seasons are innately variable. The rainy season tends to finish early during spring, but may not. It sometimes pauses before resuming. It may do so more than once. Conversely, the rainy season tends to begin late during autumn, but may begin earlier. Occasionally, precipitation begins disturbingly late.

Generally, the first significant storm with significant precipitation begins the rainy season. This may be difficult to believe with typically significant time between the first few storms. Yet, with cooler weather, elevated humidity, and shorter daylength, moisture lasts longer. Precipitation, even if merely drizzling fog, will likely dampen gardens before they get dry.

Irrigation obviously does not need to be as generous as it was during summer. Until next spring, some vegetation will require none at all. Not only will weather provide and retain more moisture, but vegetation uses much less. Refraining from manual irrigation is easy. Adjustment of automated irrigation systems actually requires more effort and awareness.

As deciduous species defoliate for winter, some other species might get more vivacious. Cacti, agave, and some yuccas that lack irrigation become more turgid with precipitation. Remaining palo verde foliage is likely to become greener and fresher prior to defoliation. Most xeric species utilize moisture from precipitation as it becomes available seasonally.

Posted on by tonytomeo · 4 Comments

Rain Shadow

P91222Hollywood is famous as the Cinema Capital of the World. Niles was its predecessor. Both are within regions of remarkably diverse scenery that is so important to cinema. Mountains, deserts, chaparrals, forests, lakes and big cities are conveniently nearby. There are not many places in the World with such a thorough mix of geography and climate. California really does have it all.

It is a challenge for gardening though. The stone fruits that grow so naturally in the Santa Clara Valley are not quite as productive just a few miles to the South in the Santa Cruz Mountains. The pears and apples that do so well in the Santa Cruz Mountains are not quite as happy in the Santa Clara Valley. Species that want a good chill in winter do not want to be in Los Angeles.

On the coastal side of the Santa Cruz Mountains, just outside of Felton, a few days of rain filled the bin in the picture above. The rain continued just as long throughout the area, including the inland side of the Santa Cruz Mountains and the adjacent Santa Clara Valley. Although the duration of the rain was approximately the same, the volume of precipitation was very different.

The water in the bin is more than a foot deep. That is about the average annual rainfall for my former neighborhood at about this same elevation, but on the opposite and inland side of the Santa Cruz Mountains. Storms must drop much of their moisture to get up and over, but are then able to retain much of the remaining moisture as they drop in elevation on the other side.

The drier inland side of the Santa Cruz Mountains, and adjacent portion of the Santa Clara Valley are in what is known as a ‘rain shadow’.

Posted on by tonytomeo · 17 Comments

Almost RAIN!

P91123KThere have been only three hints at precipitation since last spring.

The (sideways) picture above shows the same dampened hood of a Chevrolet that provided the illustration for a post on another blog on September 30.

The picture below shows a similarly dampened but different windshield from that which provided the illustration for a post on November 16, regarding a bit of precipitation two days prior, on November 14.P91123K+

All four pictures here were actually taken just after a very brief rain shower that happened just after midnight on November 19. I tried to be artistic with them, but I am not a photographer.

The picture below demonstrates how difficult it is to hold the camera steady while getting a close up picture of rain dripping from a lumber rack at night. Do digital cameras automatically extend exposure to accommodate for the darkness? Is it blurred or merely ‘abstract’?P91123K++

The rain shower was very brief, lasting only a few minutes, but dropped dozens of individual raindrops, maybe more than a hundred! In fact, there were enough of them to collectively flow from one of the roofs, accumulate in a gutter, and flow down this downspout and onto the pavement below! (I really do not know why a diverter is needed on pavement, but there it is.)P91123K+++

I bet that if all the precipitation than fell from the sky during these last three incidents could have been collected, there would have been more than a pint! As excellent as it was, it was not even the best of it. For the first time since last spring, a storm is predicted to move in and start RAINING about noon on Tuesday, November 26! Showers should continue afterward.

The rainy season will likely begin with this first storm. That is how the weather typically operates here.

Posted on by tonytomeo · 14 Comments

Not Quite Rain

P91116KMost of us here agree that the minimal bit of precipitation that fell from the sky on Thursday was not real rain. There are a few different theories about what it actually was though. It could be considered to have been drizzle. It alternatively could have been heavy fog or mist. Some of us make up silly names for what it was, such as fine rain, dusting, spritzes, sprinkles or mizzle.

Is it just me, or do those last three sound like inane kitten names? ‘Dusting’, sounds dirty and dry, which it was not.

Whatever it was, it was the second occurrence of such precipitation since the rainy season ended last spring. Something similar happened on the last day of September. I wrote about it in my other blog, with a picture of it on the hood of a parked car, rather than the windshield. I think it was more of a surprise then because it was earlier, and the chance of precipitation was slim.

This weather pattern is still within what would be considered normal here. The rainy season typically starts a bit earlier, even if with just a single primary storm passing through, followed by a long pause before more follow. There is no strict schedule though. We know that the rain will eventually start, and that rainy seasons that start late tend to provide significantly more rain.

Rain is likely just as uncomfortable here as it is everywhere else. Perhaps it is even dirtier, because it rinses off dust and crud that has been accumulating since spring. No one wants to work in their garden while it is wet. Nonetheless, because there is no rain for nearly half the year, the first storm of a season is something to be celebrated. The forecast predicts no celebration yet.

Posted on by tonytomeo · 18 Comments

‘Rain’

P80103+Like something from an old fashioned science fiction movie, this anomaly appeared in a roadway overnight. There are several more in other roadways and elsewhere about town. They are quite wet. In fact, they are composed almost completely of water. What is even weirder is that the water that they are composed of actually fell mysteriously from the sky overnight as many countless droplets all over town! Many of these droplets migrated into low spots such as this one to form what we now see in this picture.

People in other climates where these mysterious droplets are not so rare might be familiar with this sort of phenomenon. The droplets of water are known as ‘rain’. They precipitate out of the atmosphere as it cools and can not contain as much water vapor as it did when it was warmer. As the droplets migrate into low spots in roadways and anywhere else, they accumulate into these collective herds of droplets known as ‘puddles’. Many of the droplets continue to migrate as huge herds known as ‘creeks’, and even bigger creeks known as ‘rivers’. Some of these creeks and rivers migrate into really big puddles known as ‘ponds’, and even bigger ponds known as ‘lakes’. Sadly, not all of the droplets can be accommodated in ponds and lakes, so many continue to migrate out into the ‘ocean’, which is that really big pond full of salty water to the west that we are all familiar with.

Hopefully, some of these droplets of rain will stay around for a while and provide water for the plants in our gardens and forests. Ideally, some will burrow into the ground and stay for a very long time, and maybe even migrate into the aquifer to hibernate. In our climate, particularly after such a long and dry summer and autumn, these strange droplets of rain are very welcome to stay as long as they want to.