Frost Days and Ice Days: Declining Numbers over the Century

January 17th, 2013
David Easterling recently reported in BAMS** that the number of frost days per year is decreasing over the US. A frost day is a day in which the minimum temperature goes below the melting temperature of ice (32 F or 0 C). This doesn't sound good for a… more »

Hair Ice on Wood and Pavement

January 16th, 2013
The morning after a rapid cool-down, I found hair ice on an alder log. From a distance, it looked unnaturally white, like it was a bit of discarded cotton or white paper, but the closer I got to it, the more incredible it seemed. more »

Crystal-to-crystal “communication” through vapor and heat

January 5th, 2013
Two mornings ago, I saw this on the windshield of a parked car. The bulls-eye pattern wasn’t centered on any particular feature on the windshield, and there were similar, though less developed, patterns nearby. See them on the photo below. The dark… more »

Trip of the Ice Man

November 9th, 2012
The "Ice Man" -- that's how a newspaper header referred to me after I gave a recent conference lecture: A link to the article is here: http://www.sctimes.com/article/20121023/NEWS01/310230011/Featured-speaker-details-snow-crystals-SCSU-storm-conference… more »

The Crunchy Puddle Puzzle

March 24th, 2012
Who cares about crunchy puddles? As a kid, I liked to stomp on hollowed-out frozen puddles to hear their crunch. Sure, I sometimes wondered, as many kids probably do, about what happened to all the water and why it happened only to some of the puddles.… more »

Black Ice

March 10th, 2012
Black ice can form on sidewalks. It can form in parking lots. And it can form on small pieces of plastic. To be “black”, the ice only has to be noticeably darker than its surroundings. And it can be darker if the ice attaches snugly to the underlying… more »

Finally got it!

February 8th, 2012
For a few years now, myself and another ice-researcher have been trying to get a research grant from the National Science Foundation to study snow. Well, we just recently heard that the funding came through and I’ll be starting on the project in March.… more »

Caution!

February 1st, 2012
Hoar. It's just a white coating on things, so why does it make everything look more interesting? I saw this hoar coating on a plastic trash-can lid: The hoar frost on the lid had various whirls, just like I've seen on the plastic surfaces of car door… more »

Slush Fingering and Other Pond Patterns

January 19th, 2012
Here in the Pacific Northwest, we just had our first snowfalls of the season. On the weekend, we had 1 – 2 inches. This was followed on Wednesday by what the Seattle Times newspaper was calling a “megastorm”. But in the end, most areas in the area got… more »

Snow on a Freshly Frozen Pond

January 15th, 2012
Back when I was doing post-doctoral work in Boulder, Colorado, Charlie Knight, the head of my lab, introduced me to strange ice phenomena. The most memorable one happened after the weather had been sub-zero for a few days and then we got some snow. When… more »