Spring 2012 in Pictures

Time for one of my favorite posts. We get tons of photos sent into the station from viewers across the state. The number one most sent in photo? Double rainbows. ALL THE TIME! People love a rainbow, people freak over two! Of course, double rainbow viewer photos spark all sorts of quotes. "Full on double rainbow" "What does it mean?" can all be heard throughout the newsroom! There won't be any rainbows in my pictures today, but still some awesome stuff from the spring season!

The first photo was sent to us by Chris Jense. Here, we are looking at an awesome convective process. The cumulonimbus cloud, commonly referred to as a cauliflower cloud, is built by a process of warm and cool air. The sun heats the earths surface and causes the air to warm and rise. The rising warm air is cooled by the atmosphere above and eventually it becomes a large cloud like the one above. At some point, the cloud can no longer hold the moisture. The result is a short, intense downpour that we see above. This specific cloud is still building. You can tell by the sharp edges of the top of the clouds against the blue sky in the middle of the photo. Notice the bands of rain pouring down over the Jack In The Box. That's some heavy rain and most likely some small hail mixed in as well.

Linda Sullivan got a sunset snapshot of a passing thunderstorm. Again, we see the cauliflower-style clouds that extend well up into the atmosphere. The higher these cloud tops bubble up, the stronger the "updraft" is from the surface. The updraft is that column of warm rising air from the surface into a cooler environment above. The stronger the updraft, the faster the air is rising. This style of cloud is typically associated with active weather. We had a few weeks of afternoon thunderstorms around the Portland-metro area towards the end of spring.

Another convective picture, this time sent in from a viewer along I-5. Love the contrasts in this picture. The lighter clouds against the blue sky on the right side shifts to the dark rain clouds and the rain shaft on the left side. That dark area is actually rain falling from the clouds. Again, we are looking at convective rainfall here. The rain falls when the updraft can no longer sustain the rain. The weight of the rainfall overtakes the updraft and the result is the rain core you see above!

Funnel clouds are not unusual for Oregon. Tornadoes are. A funnel cloud is just a rotating cloud in the air. It can't cause any harm unless it touches the ground, then it becomes a tornado. It can be difficult to identify a funnel cloud from a still photo. It needs to be visually confirmed or else it may appear to be a low-hanging cloud. This definitely has the look and structure of a funnel cloud, however. No tornadoes have been confirmed in Oregon for the 2012 spring.

A well-timed shot was sent to us from Estacada. That looks like an impressive bolt. Notice how it goes from cloud-to-ground. These type of strikes are the only ones that produce thunder. A cloud-to-cloud lightning bolt can put a nice charge into clouds, but no thunder is heard from it.

This winter weather wasn't limited to the winter season in Portland. This is a great shot from outside the station in the middle of spring! Portland saw near 5 inches of snow over the spring, making up for the usually dry first half of winter we had.

This tranquil photo was sent in by Barbra Lane from Parkdale, Oregon. An amazing, peaceful photo after a heavy dose of snow fell near Mt. Hood.The Cascades got plenty of snow this past winter and first half of spring. That should make for a great water recreation summer.

 This photo wasn't sent in to the station and isn't even from Oregon. This photo was taken in McCalla, Alabama. I am really hoping that this is the actual photo and not photo-shopped in any form. If this is a true photo, WOW! It looks like the lightning is striking the street! The clap of the thunder was probably ear-piercing. Very powerful!

 

Finally, a little bit of astronomy. The west coast was treated to a solar eclipse on May 20th. A solar eclipse occurs when the moon travels between the earth and the sun and blocks the sun from view on earths surface. Above is the western satellite view that caught the dark spot on the earths surface. The next eclipse will be a partial eclipse on October 23rd, 2014.

Spring offers up some of the best weather and thus, weather photo ops. I'll be monitoring the summer photos and will be sure to share any interesting pictures!

Portland's Spring Weather: In Pictures

One of my favorite parts about my job are the viewer emails that we receive on a daily basis. Most emails are VERY opinionated stances on stories or programming (one of my personal favorites being a complaint about the station not airing a classic Perry Mason re-run. You know, the one where Perry wins the case?). Those emails are a story for another day. But during crazy weather times, which we have had plenty so far this year, we do receive some very cool photos! I thought I would share a few of them with you all.

This first photo was taken earlier this Spring. These are some of the most unique cloud forms, it's easy to see why! Sometimes referred to as flying saucers or "the mothership", the scientific name for these clouds is "lenticular clouds". They form over hills or mountains as moisture in the atmosphere is forced to rise over the geographical barrier and forms a cloud. The size of the cloud is normally determined by the jet stream above, causing shear to the cloud, or tearing of the cloud. In the above photo, you can see the jet stream is pushing the cloud from the left side of the photo to the right. Look at the top right-hand side of the cloud. You can see the tops of the cloud being pushed down-wind (to the right). These clouds will appear stationary, giving it that hovering, "mothership" look. In fact, the cloud is repeatedly fed moisture from the air and just re-generates a new cloud. As the air moves down the back side of the hill or mountain, the moisture in the air evaporates, thus no cloud! If you look towards Mt. Hood on a clear day, you can often see a "cap" over the top of the mountain. The cool thing about lenticular clouds is that they don't generate any precipitation and are typically a sign of fair conditions!

Our next photo depicts a visually stunning but dangerous cloud!
This photo was sent in from Woodburn. But it looks very similar to a cloud that people in the South and Midwest have seen lately. I am fairly certain that this is a cloud known as a "wall cloud". The reason why I am not 100% sure is that in order to confirm it, there would have to be rotation. But judging from the photo, I feel confident that this is a rare wall cloud in Oregon! Why is this cloud rare in Oregon? Because we only average 2 tornadoes a year! This low-hanging cloud formation is often a significant indicator of a tornado. This storm setup has a large amount of air at the surface being sucked into the storm. Imagine air from the left side of the photo being sucked into the central portion of the storm. As the air gets sucked into the storm, it quickly cools and condenses into a cloud that forms at a lower elevation. Research has shown that the lower the level of the wall cloud, the more likely a tornado is to spawn. All that being said, this storm did not tornado. The environment has to be just right and most times the ingredients just aren't there for the development of tornadoes. But if you notice this low-hanging cloud in the future...probably best to take cover, just to be safe!

The final picture I have today could be considered a cloud "relative" of the wall cloud.
What we are looking at are the low-hanging clouds at the base of the ominous dark cloud. The clouds appear right above the rooftops of the buildings in Vancouver. While very similar to a wall cloud, these clouds known as "scud" are actually smaller, often rugged individual clouds. Scud clouds form when moist, cool air falls out of the storm, this is known as the outflow. The outflow forces the warmer air around the outside of the storm to rise. As the warmer air rises, it cools and forms a cloud. So these Scud clouds are indicators of a cool outflow from the storm!
It is easier to make out the individual clouds in this photo. They just kind of linger around the base of the storm. Because they hang around the base of the storm, they often times get confused as wall clouds. This is not the case as Scud clouds do not spawn tornadoes.

There was a brief look at what has been happening around Portland this spring. The wall and scud clouds are very rare for Oregon and the NW as a whole but do occur. Lenticular clouds, on the other hand, are quite common for us. The Cascade mountain range offers us plenty of opportunities for lenticular development on top of all those mountains!