Friday, January 03, 2014

Arctic Blast Update

Here's a quick update. First, here are the bullet points at 9:00 am on Friday:

  • We will start as rain on Saturday night and switch to snow on Sunday morning.
  • At this time, 1-2" of snow is expected on Sunday. This could change.
  • Very cold air with highs in the teens and lows in the single digits is still possible early next week.
  • I'm going to increase snow chances *a little* on Monday for some quick snow showers.
  • Another round on Winter weather will come on Wednesday into Thursday.
  • The wintry weather Wed-Thu could be snow, switching to freezing rain (ice glaze).
Here is a program that we use to see various parameters. It's called BUFKIT. If you are familiar with the blog, I have shown this before. Oddly, the time stamp goes from right to left. Green bars show rain, red shows mix, and blue shows snow. This data is for Jonesboro and is subject to change:
The mix on Sunday should be a rain/snow mix and brief, but the mix next Wednesday into Thursday may be freezing rain (ice glaze). The reason we sometimes get a "glaze" instead of snow is because we have warmer air aloft. Let me explain. Here is a graph that shows the temperature as you go up through the atmosphere:

The above graph is using the latest run of the GFS. It shows an area between 2,000' and 7,000' that would be above freezing. This is the area where snowflakes would melt and become raindrops. Those raindrops would not have time to refreeze and would freeze after they hit the surface. If this materializes, we could have some glazing by Thursday morning. This storm is still SEVERAL days away, so let's focus on Sunday first!

Stay tuned!

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