Good morning… it’s a bright but cold start to the day out there with temperatures this morning starting out in the middle teens.
As a matter of fact, we’re the coldest we’ve been since December 27th. Yesterday we stopped a 28 day stretch of temperatures above average in KC.
We were exactly average and today will be the first day with temperatures below average in the Metro since December 27th. A pretty remarkable run of weather around these parts.
Today’s blog will not dive into the daily weather situation, just a heads up about an Arctic front coming our way for later in the weekend as mentioned in Wednesday’s blog.
Instead I want to show you something that was seen in Weston, MO a few days ago, and odds are you’ve never seen anything like this before, perhaps in some pictures or as part of a TV story from some other place… but not here.
These pictures and the video that follows were taken by Bill Sowell up in the Weston area on Monday morning. He sent me several pictures of what he witnessed and I wanted to include a couple to show you what was happening because there was a LOT happening here with different labels.
Here is picture number 1.
Here is picture number 2
and finally a video of everything together… remarkable
So what is going on here? Let’s go back to picture number 1.
Basically this is an amazing display of an ice halo, which is composed of diamond dust ice crystals. Diamond dust is a ground layer cloud composed of tiny ice crystals.
Typically diamond dust is found in the Arctic and Antarctic regions, but can be found here in the states as well, especially the northern states where cold and snow is more common.
In a way diamond dust is similar to something that we’re more familiar with fog. Fog is composed of water droplets, but diamond dust is composed of ice crystals. Diamond dust isn’t as thick as fog can be, sort of transparent but not totally so, and can give the sky a “glittery” look as the “dust” is gently falling from the sky sometimes. Again remember though, those are ice crystals.
Typically these ice crystals form when there is an inversion present. That isn’t unusual around these parts. Temperatures at the surface are colder while the air just above the surface is warmer.
That creates an inversion. The warmer air above the surface holds more water vapor and as the warmer air above the surface mixes with the colder air near the surface. The moisture then can freeze into ice crystals.
So how come we had these amazing phenomena show up? Well, you’ve probably in the past seen some of these phenomena, except in different ways.
I can’t anoint all this manually, but thankfully I found a similar occurrence in the past in Montana that was anointed by an optical expert Les Crowley.
So now let’s show the two pictures together and you can slide between the two to see the names better.
The only thing that I didn’t see was the subparhelion on the bottom right and left.
So how is all this happening? At it’s most basic the sun’s light is going through the ice crystals, and remember the crystals are solid objects with sides to them. The light enters an individual crystal and can be bent (refracted) or reflected to another point.
The sun’s light can actually get bent twice, and actually comes out “bent” at an angle of 22°. Different parts of the phenomena are created by different ice crystals and shapes!
The 22° halo is a more common sight around here, especially during a night with the full moon and high cirrus clouds moving through. Those cirrus clouds are composed of ice crystals.
You’ve seen halos before, you’ve likely seen sun dogs before, but all these things together is a rarity indeed!
The second picture of the “wishbone” halo though is very unique as well for these parts, and that one I’m not sure about the precise reason why that forms.
It’s opposite the sun and I went searching for a reason. I found a few possibilities but since I wasn’t sure I have an email to Les Cowley, who is an optical expert in the UK. If he gets back to me I’ll fill in the missing piece.
I believe it’s called a “anthelion” and is very rare. They appear opposite a low sun at the same height as the sun is at the time. They too are caused by ice crystals
Anyway… just a fascinating series of phenomena that odds are you’re never going to see in person all together at least. Perhaps components but not all together.
My thanks to Bill for getting me that neat stuff to show you!