Hoar Frost or Rime

I've heard the term for both, and seen both, however until I actually looked it up I didn't really know what was up.

I've spent the afternoon sitting here watching a rare fog get heavier. I hadn't really noticed that the Ponderosa pine tree beside the deck was changing until a moment ago. However, it is rapidly going from green to white. The temperature outside is rapidly dropping, and it will fall even further once what feeble daylight we have is gone.

I mentioned hoarfrost and got a grunt to the affirmative. But when I checked it out online, I discovered that what we have - at the moment - is rime. Soft rime, to be precise.

According to wikipedia: Soft rime is a white ice deposition that forms when the water droplets in light freezing fog or mist freeze to the outer surfaces of objects, with calm or light wind.

  While things may change a little later, this is the type of 'frost' we have at the moment.

I've often seen leaves looking like this back home in Victoria, and never realized it was rime. I remember scraping it off of leaves as a child and marveling at the texture and temperature. It would melt quickly in the sun when that ventured out again.

Here in Alberta, I've not really noticed it. Probably due to the fact that fog is a rarity, especially a heavy fog. Normally you can see through it quite easily, and I do find myself amused by the reactions of those dealing with it. I've had it so thick you can't see your hand in front of your face, so this is nothing.

Rime needs fog to form. Freezing fog, to be exact, and it is definitely that today. It went from a plus temp to -7 celsius. For those of you in farenheit, that's 19.4 - still bloody cold!

I'm wondering if it will in fact become hoarfrost later, or at least a hard rime. The branches look so beautiful when covered in spiky ice pointing all over the place. It really gives an ethereal appearance to the world that tickles my fancy and my imagination!

Wherever you are, I hope you are warm, dry and enjoying the day!