Spring Skiing

Nothing beats a nice spring day on the slopes. The warm sun beams down, with its barely-filtered UV rays piercing through the thin air and frying all unprotected skin. The snow starts out icy, but before long it becomes soft and smooth, with slushy snow flying out at every turn. The weather can be really crazy - a couple years ago, Vail reopened for an extra weekend after closing when it was hit with a snowstorm that dumped 3 feet of snow.


One of the best Spring skiing days I've ever experienced was nearly two months ago at Vail, a week before the closing date. Due to some lucky weather events, I experienced all three main types of snow conditions in a single day: ice, slush, and powder.


The day started out like any other: hard snow covered the trails, frozen solid from the cold night before. Turns were difficult to make on this surface, as the skis could not carve on the ice. Clouds covered the sky. It was cold, but not frigid.

Winter in the Rockies

Blowing snow lit up by the sun, which recently set behind those two peaks

A couple of days ago I went skiing. That's not unusual, because I love to ski. Every year I go skiing quite a few times - usually starting in November, when Arapahoe Basin opens, and ending in June, when the snow melts and they have to close.

When I went skiing, I brought my camera to the ski resort and took a few pictures. I didn't take any videos or photos of the skiing, but I did take some photos of the moon above the mountains.

If I come up to the mountains from Denver, there are two options to get to Arapahoe Basin. One option is to  take the I-70 through the Eisenhower tunnel, continue past Arapahoe Basin until the next exit, drive through Dillon, and then backtrack to the resort. When I go through the tunnel (which I don't very often), I like to hold my breath until I get to the other side. This is especially difficult when I run into a traffic jam halfway through.

A quicker route is to get off the I-70 onto Loveland Pass Road, which is a curvy road that winds over a mountain pass and is much more direct. This road is rather narrow and has a very steep slope on one side of it, so in snowy conditions it can be closed and I have to take the route through the tunnel.

When I was on Loveland Pass Road, I saw some flashing lights up ahead and a scrape-mark in the snow on the cliff. I immediately suspected that somebody had slid off the edge. Sure enough, when I got to the lights, I could see an autorack truck that had fallen off the edge and smashed into the trees below. There were some men climbing up to the road, and some cables connecting the fallen truck to another one which would probably pull it back up. I didn't get a chance to take a photograph, but I knew I'd be coming back that way later, so I decided to take a photo then.

View of Loveland Pass Road from the I-70, with the trucks circled

Unfortunately, the road was closed by the time I got back - probably because they were trying to pull the truck back up - so I had to take the longer route that passed through the tunnel. Then, on the highway, I took some photos of the truck accident from below. You can see my photos in this post. The trucks are on Loveland Pass Road, and the mark is where the truck slid down the cliff. I'm not sure whether the truck got back on the road - it could still be hiding in the trees, or it could be that autorack on the right in the picture.

That day must have been marked for trouble, because on the same road, only a couple of miles from the truck accident, there was another accident that involved two cars that had collided. Glass and chunks of metal were all over the road. And then there was also a 1.5 hour backup on the I-70 because of construction on one of the Twin Tunnels. I wouldn't be surprised if there were a lot of other accidents that I missed. Well, at least I made it home safe!

Colorado Flooding

A cold front clashed with the warm, moist air from monsoons in the south. As the warm air was cooled by the cold air, large clouds formed. The resulting rain began on the afternoon of September 10th where I live.

Mesocyclone

The sky was dark. Occasional raindrops pattered outside. Thunder rumbled. A computer geek sat in the glow of a computer, typing and staring at the screen as if in a trance. He happened to be working on an instant chat application, using HTML, CSS and JavaScript. When he was complete, he would host one version of the app on his Computer Science blog. He later hosted another version HERE.

Suddenly, the wind outside picked up all at once. As it howled, the windows cracked and popped. At one corner of the house came a spooky moaning sound. Only then did the geek come out of his trance; he stopped typing and turned towards the window.

That geek was me. The reason I ceased to type was because I knew that the pickup of wind was unusual, and that it can be a sign of a nearby tornado. I scanned the fields, trying to guess approximately how strong the wind was. The wind had picked up dirt and was blowing it through the fields, so I knew from experience that the wind was particularly strong. I got out of my chair and looked up at the sky through the windows, checking whether a tornado was forming. Ever since I was very young, I was fascinated with tornadoes, and was always on the lookout, hoping to see one. I sometimes dream about tornadoes. Unfortunately, we live in a place where tornadoes are rare, so I've only seen a single tornado my whole life.

I noticed clouds turning in the sky - a mesocyclone. A mesocyclone is a vortex of air within a convective storm - that is, rising air that spins. I called the rest of my family to come look at the turning clouds. I ran and got my camera, and started filming. I really hoped some kind of tornado would form; even a small, weak one would have satisfied me. I watched the clouds as a funnel started to form. Then it dissipated; a tornado never formed.

I had been hoping for a tornado, but what I saw was the next best. I had read a lot about mesocyclones, cumulonimbus clouds, and thunderstorms, and it was very interesting to see it in real life. I could even see the opening for the rear flank downdraft.

I later took the videos I got and removed parts of them. Here's the result:

Pileus Clouds

A cumulus cloud with pileus. This pileus is a small one.

There are multiple pilei on the cloud in this photo.
See if you can find them.

A Pileus, pronounced pie-lee-us, is a small, smooth, silky-looking lenticular (lens-shaped) cloud that can appear above parts of either a cumulus or cumulonimbus cloud. (If you don't know what a cumulus cloud is, click HERE. Cumulonimbus clouds are basically very large cumulus clouds.) A cloud attached to pileus is said to be "with pileus" or to "have pileus".

Clouds with pilei can develop into very large
cumulonimbus clouds.

Pilei form when a strong updraft at a lower altitude acts upon air at a higher altitude, and causes it to cool below its dew point. The result is that as the air cools, the water vapor in it condenses and forms a cloud. Because of the conditions required for it to form, a pileus cloud is usually a sign of severe weather; the cloud that it forms above is likely to develop into a cumulonimbus if it hasn't already.

Early this afternoon, it was bright and sunny, but there were a couple of cumulus clouds with pileus, so I immediately predicted a thunderstorm. Sure enough, only a couple hours after that, it started raining harder than it has in a long time, and I could smell ozone from the lightning that kept flashing outside.

It isn't raining any more, but I can see a huge cumulonimbus far in the distance, and dark clouds overhead.

Summer Drought

The actual sun appeared bright red, but my camera picked up some invisible radiation as violet.
This photo was not enhanced.

Last year was very dry. Wildfires raged through the state, and a firework ban on Independence Day made everybody even more sorry about the lack of water.

I think this summer is turning out to be a repeat. So far we've had 3 historically significant fires: the Black Forest Fire, which burned 14,280 acres and was the most destructive ever recorded in Colorado (in terms of property damage); the Royal Gorge Fire, which burned 3,800 acres and jumped the Royal Gorge; and the West Fork Complex, which is still burning 0% contained, and has so far burned more than 83,004 acres.

Photos of an affected area, arranged  in chronological order.

Just today, we watched a wildfire almost in our backyard, and saw the firefighters putting it out. We packed up in case we had to evacuate, but they got it under control and put it out. They had a helicopter with a water basket hanging below it, and the pilot kept getting water from a facultative lagoon at a nearby sewage treatment plant and dumping it on the fire. He was amazing at flying that thing; he could even fly sideways.

I hope things improve. Wildfires might look neat, but they aren't exactly safe. I don't like firework bans, either.

Black Forest Fire

Six days ago, a fire started in Black Forest, Colorado. The wind was very strong, and the fire quickly grew to become the most destructive fire in the history of Colorado.

Warm Weather

Finally - it's nice and warm outside. The meadowlarks are singing, and cumulus clouds fill the sky. In some places, this kind of weather has been going on for the past couple of months. Where I live, though, we've been having cool weather, so a 70° day seems very warm.

Here are some of the pictures I took today:

Cumulus Clouds

Cumulus is the Latin word for pile or heap, and cumulus clouds certainly fit their name! They look like fluffy mounds of whipped cream floating in the sky, and often have a shape similar to that of a cauliflower.

 Cumulus clouds form when relatively warm, moist air rises and cools below the dew point. The moisture in it then condenses into tiny water droplets, which form the cloud. The relative humidity (how "full" the air is with water) helps determine the height at which the moisture condenses at, which is the base of the cloud.
In this little video I made, you can see how the clouds form, with the moist air appearing a light mist rising out of the ground. The moist air is not visible in reality, but I added it to help illustrate the idea:

A cumulus cloud constantly undergoes change, as long as moist air continues to rise under it. The water droplets at the edge of the cloud usually evaporate, so the cloud loses water as it gains it. In a time-lapse, the clouds appear to boil.

Here are the main types of cumulus clouds:

Cumulus Humilis

Cumulus humilis clouds are small things with little vertical development. They indicate that the temperature of the atmosphere in the area does not drop very much with altitude, if at all. When seen in the morning, they signify an unstable atmosphere, possibly resulting in thunderstorms.
These clouds are the most likely type of cumulus cloud to be seen during Winter.

Cumulus Mediocris

Cumulus mediocris has a greater vertical development than that of cumulus humilis, but is not as large as cumulus congestus. When these clouds are seen in the morning or early afternoon, they often indicate storms later in the day.

Cumulus Congestus

Also known as towering cumulus, cumulus congestus are tall, towering clouds that often precipitate (rain, hail, etc.). They are similar to cumulus mediocris, but are a lot larger and taller. They often develop from cumulus mediocris clouds, but may develop from other types of clouds as well. If this type of cloud continues developing, it can become a cumulonimbus cloud. The one in the picture above became a small one within a few minutes.

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A Big Thunderstorm

On the day after the June 5th Venus transit, which was the last until 2117, we had the first big thunderstorm of the year.

Before the storm, it rained. Usually we don't have rain followed by sunshine followed by more rain, so when it stopped raining, I thought that was the end of it. It wasn't. When I looked up at the sky, I saw some gigantic clouds. You know the puffy cumulus kind that float by on a sunny afternoon? Well, these clouds were similar to those, only about 20 times larger. These were cumulonimbus clouds - the most dangerous type of cloud. And they were heading my way.

Not long after I went back inside, it started getting dark. Rain began to fall, followed by hail. Lightning flashed again and again as the hail pelted against the windows. I heard that there were 3 tornado warnings. When I looked outside, I couldn't see very far at all, so a tornado could come and I might not even notice until it tore the roof off. I got excited, and started watching very carefully for tornadoes. I've already seen a tornado once, but that wasn't enough; I want to see a few more. Anyway, sometimes the hail would quiet down, so I thought there could be a tornado nearby. Other times it would start rumbling on the roof, so it sounded like a tornado was coming. And meanwhile, I ran from window to window, checking for tornadoes. I never saw any.

Some of the hailstones in that storm were really big - the size of Ping-Pong balls, and larger. Anybody that walked out into the storm wore buckets or metal lids on their heads. If a hailstone hit them on the head, it would hurt a lot - those hailstones fell so hard they even dented our cars, one of which was totaled!

Not only were the hailstones large, but they were numerous. They filled the gutters and rain spout, causing the rain to spill over the sides or leak into the roof. I saw water running out of an air vent in an overhang on the outside of our house. My dad went outside and cleared the rain spout so the rain could drain to the ground more easily, but he didn't realize the hail in the gutters was a problem until much later.

After my dad cleared the rain spout, I noticed that a lot of lightning was flashing directly overhead. It wasn't reaching the ground: the clouds were zapping themselves. This was a good time to take some pictures. I set the camera to take long exposures, and aimed it up at the sky. Unfortunately, the lightning flashed at all the wrong times, and when it didn't, it was almost invisible or was at the edge of the picture. I didn't get anything good until the storm died down.

I later learned that many thousands of people's property was damaged during the storm - not only from the hail, but also from tornadoes. There were at least 20 in Colorado that day. And I never even saw a single one.