Possibility For Thundersnow With This Snowstorm?

[Saul Trabal]

What are the chances of thundersnow with this upcoming snowstorm? Can this be forecast? If so, how?

 

[Chris Nuttall]

We need one of two things to get thundersnow. Instability or strong UVVs. Thundersnow is convective precip. So, basically, it's the same type of ingredients that go into generating any convective storm with the obvious addition of cold enough surface temps to get snow at the surface.

If you want to forecast thundersnow, look for any areas of CAPE..both elevated (for elevated convection) and surface-based. Also, look for areas of strong upward motion. So, look at some forecast soundings. I haven't looked at any soundings myself, but I don't think we are going to have much in the way of CAPE. However, if things verify, there could be a chance of some decent dynamic lifting. So, the chances of thundersnow are there probably around the OK/KS border where the heaviest snow will be.

I hope that's right. My winter weather expertise is somewhat limited except to forecast precip amounts and placement. I'm much better at that.

 

[Robert Dewey]

Actually, looking at CAPE probably won't help much unless you are calculating lake induced CAPE for a lake-effect event.

You really need to look at cross sections and time-height sections to get a better handle on things. There are three main types of instability...

Absolute instability - Theta decreases with height
Potential instability - Theta-e decreases with height
Conditional instability - Saturated theta-e decreases with height

Then, for "CSI", you have Conditional Symmetric Instability - which adds the geostrophic momentum surface into the mix. With that, all you do is take the "parcel" along the geo. momentum surface, and if the saturated theta-e decreases along that surface, it's potentially unstable.

Of course, you also need some lifting, or that instability is useless.

 

[mikegeukes]

Move to thundersnow with cg Delete please. THanks

Mike

 

[Mike Johnston]

Saul, did you have some kind of premonition of this event? Goodness, not only thundersnow, but CG reports and descriptions of orange balls of lightening from passengers in that airplane. Given that you were asking a question of whether and how this could be forecasted, I take it your post wasn't a forecast, but something must have prompted you to consider this topic for this particular storm?

 

[Saul Trabal]

Saul, did you have some kind of premonition of this event? Goodness, not only thundersnow, but CG reports and descriptions of orange balls of lightening from passengers in that airplane. Given that you were asking a question of whether and how this could be forecasted, I take it your post wasn't a forecast, but something must have prompted you to consider this topic for this particular storm?

Nah-I don't have any cool super powers. Sorry to dissapoint.