Did Man-Made Snow Fall In McMinnville?

With no storm systems even close by–and nearly 50 degree temperatures up on Mt. Hood…you can imagine I was stunned to hear it had just snowed in McMinnville and we already had the pictures coming in to my KOIN Local 6 colleague, Meteorologist Matt Brode.

Right after that, I found out we’d also had several calls from different people who were seeing the snow.

And if seeing is believing, well, I was a believer once I looked at this picture that Judith sent into news@koin.com on Tuesday December 6, 2011. I mean, you can clearly pick out the flakes falling down!

Matt & I discussed the fact that although it’s rare, it’s not impossible to get snow from low clouds and fog. The scenario goes something like this:

• Air in the clouds & fog becomes so saturated or loaded with moisture that it has to drop some–and it does.
• In most normal Willamette Valley scenarios, this is drizzle. We know about that in the northwest, right?
• But because of an inversion–with freezing air stuck right down to the valley floor–this moisture squeezed out as a few minutes of light snow in a small area.

I read a recent study that focused on ‘snow from fog’ events in the United Kingdom. The researchers found that most cases were linked to some sort of human activity, like a local factory or plant–that released moisture into the freezing sky and that became snow.  Interesting, I thought.

But maybe the McMinnville case just happened–one of those unusual but not impossible scenes that play out somewhere in the weather world everyday.

Danielle sent in this photo–looks like it snowed in her part of McMinnville but it was probably a combo of falling snow–and all day freezing fog.

Was Snow In McMinnville Man-Made?
But back to the ‘man-made’ theory. It was during my five o’clock newscast when I received the following email from Monty, who claims to live in McMinnville. Here’s what he wrote:

I have seen this happen only a few times, but when conditions are
just right, freezing air aloft, very minor almost dead air, freezes steam
from a local creamery (Darigold)  causing “snow” to fall.

Today, the area affected was east McMinnville, 19th street to be exact, in the area of
McDaniel street.  As I drove through that area today, it was beautiful,
every bit as pretty as Mt Hood during a light snowfall; ice on the trees,
bushes, blades of grass, even a little on the sidewalk in one area.

But, travel several blocks in any direction and there
was no snow.  The air aloft was pushing this steam east, it was freezing,
and falling as light snow on this limited area of town.  At the grocery
store it was a fine ice mist falling that was exactly as snow.

In a lot of ways, that’s a very believable explanation for what happened. And it gets me thinking: wouldn’t that be cool if one of these times it was ice cream falling from the sky near that creamery?

The kids would love that one!