Monday, January 09, 2012

First Snow of 2012?

This is a program that we often use, especially in the winter. It is BUFKIT and it helps chew up the data that we look at each day. The timestamp at the bottom of the graphic goes from right to left. Click the image to enlarge.

I'm going to make this blog short and sweet because we are still several days out and the forecast is likely to change a few times, but since it is the first real sign of snow in 2012, let's have fun with it. Two features jump out on this graphic. The first is the green. That is the rain coming in tomorrow and tomorrow night (Tuesday). The next thing that jumps out are the blue bars. Blue on this program indicates snow. This would be Saturday night through Monday morning.Strictly using this program and taking it as truth (which we should not yet), it shows a 1-3" snowfall for parts of Region 8. So how do we know  to think "Snow" instead of freezing rain or sleet? Let's take a look at the forecast sounding using the same data and I'll explain.
The above image is a forecast sounding and shows us what the temperature and dewpoint may look like at 7PM on Saturday evening according to this model. As you go from the bottom to the top (ground upward), the red line is the temperature and the green line is the dewpoint. I have clearly marked the freezing line in blue. Using this forecast sounding, the freezing line as you go up through the atmosphere is at 400 feet or so. 400 feet is not enough of a gap to melt the snow, so it would be snowing even when the temperature at the ground is above freezing. While it may be harder for the snow to stick, it would be snow... if this model verifies. Let's fast-forward in time a little bit...
 In the above image, we have fast forwarded to Sunday morning at 7AM. Notice, the red line is completely to the left of the blue line, which is the freezing line. This would be all snow if this model verified. Later in the season, I'll explain some mixed precipitation soundings.

It's early and that's why I'm not going to drag out any details or say that I'm sold on anything, but it is something to watch. Bryan McCormick has also blogged about this setup and you can read his blog post here:

I'm taking a sick day to help my wife who is sick and to take care of the kids. I hope to be back to work tomorrow, but tune into B-Mac tonight for the latest forecast!


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