Hey all!
I apologize for the blog silence, and I know I had promised this post would be about straight line winds, but this summer has been terribly busy for me! I wanted to share an event from May 18th that was very troubling for me, but also quite fascinating to learn from!
Here's an animation of 8 photos I took within the same minute:
That minute was 4:11PM, Mountain Daylight Time.
Great, I got photos! Not exactly, these photos are really low quality when it comes to photography, I have the zoom out about as far as it will go, and you can see a lot of glare from the windshield (and possibly some refraction caused by water droplets):
There were also a lot of nearby scud:
So how do I know this was a funnel for sure, let alone possibly a tornado? Let's examine the cloud structure and their general motion. Here's a view of the storm at 4:07PM MDT, circled in red is the area where our funnel developed:
And here's the low altitude velocity sweep from about that time, along with our position at the time of possible touchdown (which I traced via my Google maps timeline):
Given the clouds are rotating and lowering towards that point, I think it's safe to say we'd be in the right part of the storm! We also saw the initial descent, but scud were quickly sucked into the mix. If you look at the animated photo you can see that the funnel actually sucks up a lot of nearby scud!
Here's a photo and sweep (same position marker, us at 4:11) from after:
location of the possible tornado is circled in red above
We believe we were looking to our Northeast, marked here onto the two velocity sweeps shown above "possible tornado:"
The rotation didn't go very high into the cell, so this was not caused by mesocyclonic rotation, but was likely a convective eddy, or possibly a landspout. I've discussed this with a few meteorologists, and finally feel confident that what happened is known... We don't know! It was a funnel, but was it a tornado? For that answer I turn to physics: yes... and no! This tornado did and did not happen; unless we can find irrefutable evidence it touched the ground or didn't, we can't really say whether or not it existed. I think, ironically, the ridge that boxed in Schrödinger's Tornado, is part of why it formed in the first place. Hopefully I will be able to write my straight-line wind post soon, until then stay weather aware!!
Hi again everyone!
Today, as promised, we're going to be talking about how a surface-based rotation becomes a tornado. First, let's touch on how windshear produces a mesocylone.
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Windspeed increases with height, which begins rotating the air, as this tube of air is lifted by a thunderstorm upraft it tilts more vertically as the updraft rotates around this air. It doesn't just tilt at a 90° angle, it stays somewhat slanted, giving the storm cell the advantage of not destroying itself by pushing directly down on its own updraft.
Mesocyclonic tornadogenesis occurs when the downdraft is not much cooler than the updraft, allowing the storm to wrap its own downdraft around the mesocyclonic updraft and being able to warm it enough to travel from the ground back into the updraft
Gustnadoes teach us how little is needed to make winds rotate, they often form through simply the winds' interaction with the ground, its naturally and unnaturally uneven surfaces, and the inherent miniscule instability; snagging, tunneling, and interacting with the warmer air around them at different points along their paths.
Dust devils are an interesting animal however, because they often have an element of lift akin to a tornado. Leaf devils next to your office building probably rely on a wind tunnel stretching effect, but others are quite similar to tornadoes, and rarely, some are!
Note how the dust devil above lifts and even tilts. As warm air rises from the surface, cooler air takes its place. Now let's say that air is rotating, which as we know little is needed to make air rotate and we have two examples of rotating air above, but only one involves an updraft. So let's say you have essentially a dust devil on the water: rotating water rising into an updraft; given that cumuliform clouds are created by water in an updraft you can probably understand why waterspouts are fairly common. So what happens when there's just enough moisture going into the updraft of a dust devil to form a cumuliform cloud above? Well, this creates a tornado! What happens if a dust devil is engulfed by a cloud updraft? It's a tornado!
Here's an example of a possible tornadic dust devil. The uploader claims to have seen corresponding rotation in the clouds above, which would make this a "landspout." Basically, like a dust devil on water is a waterspout, but rather a waterspout on land!
Next time you see one, go ahead an enjoy your little waterless tornado! Next time we'll discuss straight line winds. Stay weather aware until then, especially anyone caught in today's potential outbreak!
Welcome back!
Today we're going to discuss microbursts, they're kind of the opposite of a tornado. Instead of air being pulled through a small rotating tube into a warm thunderstorm updraft, a microburst is a pocket of cool air shooting down from a thunderstorm and expanding when hitting the ground.
A dry microburst occurs when the air hitting the ground from a storm doesn't contain any moisture, they are most noticable when they kick up debris, here's a photo I took in Castle Rock, Colorado:
I did call in to report. Last I had heard, National Weather Service Denver/Boulder was investigating a microburst, I'm not exactly sure of what damage, if any, was caused.
A wet microburst is when moisture reaches the ground with the microburst, I actually took this picture when I was working at Pizza Hut in Peyton, Colorado:
Notice the rain going sideways at ground level, and how it originates on the top left corner of the photo.
Microbursts are fairly common here in Colorado, if you're under a burst of rain that seems to be forced to the ground faster than gravity can take it, you may be under a microburst. Not all microbursts are violent in nature, so odds are you'll encounter at least a small one at some point in time if you experience enough thunderstorms. That said, microbursts have had the stength of a strong tornado (EF2/3). Just stay aware during a thunderstorm, it will keep you safe and allow you to truly enjoy their power and beauty more!
My next topic of discussion will be how a dust devil can turn into a tornado, until then stay weather aware!
Hey all!
Today I wanted to talk about gustnadoes, as they're quite underrated; sometimes they reach tornado strength, though they're much more difficult to forecast.
Let me tell you about my first encounter with a gustnado;
I was driving in my first car when the typical afternoon thunderstorms rolled in. At a stop light I felt the wind go from calm to the car pulling to the right. Sure enough, to my right there was a debris cloud, reminise of a dust devil churning its way across the road right next to me... So how do I know that was a gustnado?
Truth be told you can't always tell, in fact, arguably a landspout, a strong dust devil, and a gustnado are virtually indistinguishable at times. However, given the relative location of the ground rotation in comparision to incoming storms, and no confirmation of cloud-based rotation, I had concluded this was the first gustnado I had seen.
Figure 1: A photo I took of a dust devil near Canon City, notice there are no clouds in the immediate area.
Figure 2: A gustnado I photographed near Deer Trail, Colorado. Notice: there is no discernable connection to the cloud base.
Figure 3: A gustnado my chase partner photographed along I-70. This was the second debris cloud we saw on this chase...
Figure 4: A photo I took of a supercell tornado roping out near Eads, Colorado. I felt this photo showed an obvious connection between cloud and ground.
Figure 5: A photo I took of a cycling tornadic supercell near the town of Fort Morgan, notice the cloud reaching from the top towards the ground
What makes this even more confusing is that dust devils and gustnadoes can both turn into tornadoes; should the circulation connect to a cloud base it is now a tornado. But what about a tornado debris signature? If said gustnado is strong enough to loft debris, and if embedded within the RfD (rear flank downdraft), could, at least in theory, send a debris signature as well.
A good example of a strong gustnado was at the Indianna State Fair grounds, here are two videos taken by two separate attendees of the concert that was hit head on:
Note in the first video you hear someone ask "Mark is that a tornado?" If you watch, when the stage gets hit, the dust is rotating, and as it passes the stage you will notice the flag pole pulling into the debris cloud from the opposite direction as it passes.
I got too close during the storm in figure two. There were numerious splitting supercells on the high plains, and by the time I knew I was too close it was already too late;
The gustnado was near a hail core with stones varying from golfball to softball size, as the gustnado approached my vehicle (even touching the highway girders next to me) I made an attempt to flee through the hail core. Hail smashed my car, and after the gustnado dissipated I drove towards where I has seen it, and drops of mud rained on my car. I kept going and ended up stuck in the mud outside of Akron, Colorado. Thankfully, the storm had passed me already, so I snapped photos:
Because I got impatient and went back West, I had missed all the tornadoes that day, including the multivortex tornado near Wiggins, Colorado, which I had forecast happening within 20 miles the day before. A tough lesson learned, but a lesson nonetheless, and I came out alive. I learned to trust my initial forecasts a little more, and to be more patient, less emotional, and more observant of changing weather conditions and the overall pattern.
Next time we'll talk about microbursts, thanks for reading, stay weather aware everyone!
Hi all,
Welcome to my weather blog! I'm Stefan Klein, a Skywarn spotter for the National Weather Service in Pueblo,Colorado. I like to study weather first hand, by applying forecasts, experiencing it, and documenting it. My favorite phenomenon is certainly supercell thunderstorms, but I do enjoy all manner of atmospheric events. I've considered a blog for a little bit now, and I decided a good day to start it is today; one year after the record-breaking wind event in Colorado Springs. The airport recorded a wind gust of 80mph, their highest ever, and a gust of 101mph was recorded on the Southwest side of town. I was living downtown when this happened, here are a few of the photogrpahs I took:
This storm caused over $1.5 million in damages, and killed two people. It ranks amongst the deadliest natural disasters in the area's history, with as many fatalities as the Black Forest fire, and the Waldo Canyon Fire. Anyone who lived here and was here that day certainly remembers!
I plan on making my next post about gustnadoes, until then stay weather wary!
