A fun weather day! The cold air really never drained away from the higher terrain of the Pikes Peak region. In fact, it was being pushed up against the southern slope of the Palmer Divide all day long and we spent most of the afternoon in the teens with clouds re-developing and even some flurries and light snow showers. The edges of these shallow airmasses after the main system moves through is a situation our computer models frequently struggle with and many times we just have to observe what is happening now, project it mentally 6 hours out, and then re-evaluate. The key to tonights forecast is leaving clouds and areas of fog in as possibilities until we actually see the wind switch around out of the north or northwest. That will indicate drier air pushing off of the mountains and will signal the onset of the airmass draining away. Much like water in a bowl, these cold/shallow airmasses seek the lowest lying areas because they are very dense (”heavy” due to gravity’s influence on it) and will end up exiting eastern Colorado along the Arkansas River.

Until this process happens, we’ll see areas of low clouds and fog for areas that are high enough, such as Monument and Briargate as of mid-evening.

Interesting to say the least. When I worked Friday evening, it appeared that snow would wait to really get going until mid to late afternoon Sunday. It endend up starting about 6 hours earlier and actually ended up affecting how much snow accumulated because it melted all day as it hit the ground. As we went into the evening, when the snow obviously is more likely to stick, the main source of lift (temperature gradient in the middle levels of the atmosphere) had fired south into northern New Mexico and so snowfall rates overnight were pretty light.

During the day Monday, a second cold front arrived and dropped temperatures within the vertical atmosphere to perfect snow making temperatures. As such, the light upslope into Monday evening is lifting the air just enough (sometimes it literally needs just nudged upward) to make big, airy, fluffy dendrite snow crystals. These are the kind that literally be broomed off the walk or blown off the car windshield, but can quickly pile up 2, 3 or 4inches! Some folks have been getting their most significant accumulation with this storm over the last 6 hours! UPDATE: Julie Shrank sent a great picture to me Tuesday morning of the snow that ended up being a 50 to 1 ratio snow (meaning that 1 inch of liquid would equal 50 inches of snow), about as high as you’ll ever see it. The liquid to snow ratio is usually closer to 10 or 15 to 1.

Here are a few grabs from our Neighborhood Weather Network this morning, really pretty out there this morning!

I harped and harped on it Thursday and Friday. “You’ll either be in it, or out of it, there really isn’t a dividing line”. I was talking about the cold air and the resultant clouds and light precipitation that caused quite a few headaches on the roads for those trying to get around on Saturday in particular. On Sunday as I went into the grocery store at noon, Woodland Park was at 54 degrees with a lot of sunshine and most of the metro areas were in the teens and lower 20s.

We’re still dealing with this today and being that I’m now in the office I can show you some graphics to illustrate this concept of the shallow and dense cold airmasses. Check out the NWN shots from around 230.

 Eads at 230 was still holding on to 39 degrees and still had quite a bit of low cloud cover. Below you see that Canon City had cleared out and made it to 50 degrees, but at the same time the Pueblo airport was only at 44.

Briargate, one of the higher areas in the Colorado Springs metro was running about 6 to 8 degrees warmer than many neighborhoods near downtown. As you look toward Pikes Peak in that shot, the haze at the base of Pikes Peak (sorta looks like a Bob Ross painting!) represents where the deeper cold air was. A reminder that it is lower downtown along Monument and Fountain Creeks than it is in the Briargate neighborhood. This is important because the cold airmass that moved in Friday night is very dense (more air molecules in a given area) than the relatively warmer air over the mountains. Because of gravity, this air acts “heavy” and is most noticable over the lowest areas. Check out the visible satellite imagery from a little after 230. It shows the low clouds associated with the deepest part of this cold airmass hanging out along the Arkansas River Valley (the lowest area in southern Colorado).

The image above right very nicely illustrates how I describe this cold air. As it sloshes up against the foothills, it is a lot like ocean waves crashing on the seashore. It moves up the beach, then back out, then back up and your feet are either wet or not, there really isn’t much of a dividing line. In this metaphor, the water is the cold air and the beach is our local terrain. Many times over the winter months we’ll find that areas in the foothills and over the mountains will end up warmer than some of us at lower elevations. When this happens, you know that a cold and dense airmass from Canada has moved in for a few days!

By the way, many times in these scenarios we know we can not “nail” the temperature forecast, we simply try to make the point. It is next to impossible to pinpoint where the border of the cold airmass will be at any given time and it will move up into the foothills and back down through the course of the day. Many times the difference between being in the cold air and out of it can be 20 degrees or more with a dividing line of less than 1/4mile. In these situations we just hope to send you out the door with an idea of what is happening overhead…

Just a few screen shots from our Neighborhood Weather Network, pretty stuff out there!

Started out looking pretty nice in some areas, check out the view from Westcliffe this morning…

Of course we have had some snow, and rain, and graupel (snow pellets, small hail) and everything else, here’s a shot froma very wintry looking Cripple Creek!

Wasn’t too long though before the snow was flying over the high country, and the rain was moving over us.  REAL-TIME TRAVEL TRACKER picks up the snow via the cameras and the road conditions as reported by CDOT, you’ll see us using this more often soon…

Rain vision shows that the northwest side of town had quite a bit of rain (the yellow area is the very SE part of the Air Force Academy and indicates 3″) while most areas had little to none. The graphic above left shows that not only did heavy rain occur at the Academy and in Peregrine and Rockrimmon, but at least a couple homes had some very large hail as well. The 1.5″ hail was very localized as most areas had quite a bit of hail that was on the order of .33″-.75″ as the two pictures below indicate.

I caught strikes from Pueblo West, Pueblo, Cripple Creek (both cameras), 8th Street and Abbot and Briargate tonight. But the best images by far were from Canon City where we got more than a half inch of rain with the evening storms.

Briargate got hit pretty good in the afternoon with quite a bit of 1″ hail and rain on some streets equaling more than an inch.

We call that title an attention grabber, in this case the snow part.  No, we are not forecasting for any snow, but today is the earliest day that snowfall has occured in Colorado Springs, happened in 1961 if you’re interested.  I’m done with any talk of snow now…

Smoke from fires all over the west continues to make for an eerie, at times beautiful sky.  Great photos from our sunsets over the last several days from our viewers.  I thought this shot was different as the sun was rising over Pueblo West.  Thought myself that the sun looked a lot like the moon as it peered through the haze, Vida thought it looked more like and ocean sunrise/sunset, either way it’s different.  Here’s the photo…

Photos of double rainbows abounded in Pueblo earlier this evening. The top two are from a husband/wife team that is always trying to out-do each other with weather pictures. The lower two are courtesy of Steve Hodanish, a senior meteorologist at our local National Weather Service office in Pueblo. I got a question on twitter from @SchwartzNow that asked what caused a double rainbow. These occur when light inside a raindrop ir reflected twice instead of just once as is typically the case. This causes the secondary bow. It is always the outer bow,  as it ends up at a greater angle than the primary bow. Its always fainter and the colors are INVERTED from the primary bow. Red ends up on the inside of the set and blue is on the outside. If you look closely, you’ll notice that the area between the two bows is a little darker than the rest of the sky. This is called Alexander’s dark band. It contains less light than other areas of the sky, because the light has been bent away from this area…

Below on the left you see how light refracts and reflects as it enters/travels in/exits a raindrop when one rainbow is present. While this process still happens when two rainbows occur, a second rainbow is created by light that is reflecting twice while inside the raindrop. Note that some of the light escapes out of the raindrop on each reflection so with two reflections the secondary appears fainter than the primary. It also exits at a larger angle compared to the incoming light, which is why they are separated when you see them.

Also on twiiter today, @sarah719 took a picture of some iridescent clouds, you see here picture on the left. I described the colors as looking like a soap bubble, I put another example on the right. This iridescence occurs in thin clouds that have water droplets of the same size. If its cold enough for ice, we’ll end up with sun dogs…