Wednesday, February 18, 2015

Icy Friday!

Who's ready for more wintry weather? There are not as many hands being raised this time, but we may have another mess brewing on Friday. The good news is, it may not last long, as we warm up on Saturday. Here are the bullet points of our thoughts ... and then I will get in more detail:

  • Snow and sleet starts on Friday morning, possibly before sunrise. SEMO has the best chance to start as snow.
  • Sleet continues for a good part of Friday, off and on in intensity.
  • Accumulations are likely, mainly of sleet. We will talk totals tomorrow.
  • Everyone changes to freezing rain late on Friday. (Glaze of ice)
  • The longer the freezing rain continues, the higher risk of power issues.
  • We change to ALL RAIN by Saturday.
  • Thunderstorms are possible on Saturday.
If you are pressed for time, you can stop reading now. If you want more details, let's break down what radar could look like and the vertical profiles of the atmosphere to explain WHY it will be sleet, freezing rain, or rain. 

Let's start with Friday morning. We should start as sleet or snow, depending on where you are located:
The reason I think we will be mainly sleet is due to a melting layer aloft. That layer will melt the snow, BUT there will be enough time for the "hydrometeors" to refreeze before hitting the ground. Therefore... sleet or snow pellets, which are partially melted snowflakes that refreeze:
By Friday evening, the melting layer gets larger and the time for the hydrometeor to refreeze lessons. This would likely lead to FREEZING RAIN:
And the vertical profile of the atmosphere looks like this:
By Saturday morning, the melting layer is extended down to the surface, as warmer air overtakes the arctic airmass. We will likely see all rain at this point and some thunderstorms. Heavy rain is possible:

I actually would not be surprised if we see a few strong storms through the day on Saturday... especially on Saturday night.

That's all I have for now. Have a great day!


Rufus&Buddy said...

Wowow! Thank you for the full update ... Rain will be good!

LindsayP said...

Thanks for the breakdown, Ryan! :) I don't care how hard it rains, as long as it washes all this mess away!! I just pray we'll see some sun during the day on Sunday to dry up all the water before we fall below freezing again. ;)

Deb Jackson said...

I'm thinking about going back to bed until Monday. Thanks for all the updates. Good job!