Sunday, February 15, 2015

SLEET Storm or SNOW Storm

Do you remember the sleet storm we had last year? I'm really thinking this storm could be very similar. Sleet accumulates differently than snow. 3-5" of sleet is like 10" of snow. That's why this storm is difficult. I've explained this before, but let me show you how sleet forms. Below is a forecast sounding for tonight. Think of it as a vertical profile of the atmosphere in a graph-like image. The red line is the temperature, the green line is the dewpoint. You measure the temperature as you go up through the atmosphere with the numbers at the bottom. Here's what to notice:
  • Snowflakes form high in the sky!
  • There is an area between 4,000-8,000 feet that is ABOVE freezing. 
  • Snowflakes melt to raindrops there.
  • From 4,000 feet to the ground, we are below freezing.
  • The raindrops FREEZE into little ice pellets.
  • If they do not have time to freeze, they land as liquid and glaze exposed surfaces with ice.
Here's a great map that shows the "liquid equivalent" of PREDOMINANT precipitation type for tonight. Orange is sleet (ice pellets), pink is freezing rain (Ice glaze), blue is snow, and green is rain. Click to enlarge:
Here's what to watch though! IF the atmosphere cools that melting layer between 4-8K feet to at or below freezing, it will change to all snow. If that happens early, we could have a dumping of snow. That's what we are watching tonight! Fun, right?

Stay tuned!


Chocmom said...

Is it looking like it will start before mid-night today?

Healthier is Happier said...

Bless your heart :-/ Not fun trying to keep everyone informed with ever changing conditions- THANK YOU

Anonymous said...

Sounds basic. But clearly a forecasting nightmare.

Shawn said...

The weather channel says something totally different than kait8! So what is really going on? Is it going to be up to 6 inches of snow or sleet and freezing rain? Forecast changes every time I look at it! I'm so confused lol! HELP! :)