The Good, The Bad, And The Ugly
2014-11-17 17:25:59.000 – Michael Kyle, Weather Observer/IT Specialist
When I started my shift early this morning the radar was showing snow across much of the state. With some heavy bands passing through much of Southern New Hampshire and Maine, and slowly pushing their way towards the White Mountain Range. During my first observation this morning I reported a temperature of 22, which was a 7 degree jump from the prior hour. This was the first sign of the invading warm air and that the snow was not going to last much longer.
Four hours later the temperature finally made it up to 25 degrees and the snow came to a stop. In place of the snow we were now getting a mix of ice pellets, and freezing rain. This meant that we were not only seeing rime ice, but also seeing glaze ice starting to form on the summit. Luckily it was still just lightly glazing so it was not terribly hard to de-ice. However, conditions were continuing to deteriorate.
At around 1:00 PM today, or about 8 hours after my first observation, the freezing rain and glaze ice was at its worst. The glaze was accumulating at about one inch per hour and peaked at about two inches that hour. This made it difficult to walk around the summit, but also making the de-icing our instruments extremely difficult. The reason why glaze ice is so hard to de-ice is because of the way it forms. Rime ice forms by minute liquid water droplets that freeze instantaneously to a surface. Because of the small droplet size, air pockets form in between the rime ice. Glaze ice forms under similar circumstances, but with larger droplets and temperatures closer to the freezing point. Which allows the glaze to freeze over a longer time, making it more densely packed and hard to break apart. This is why I consider de-icing glaze ice to be the ugliest part of my job.
Michael Kyle, Weather Observer/IT Specialist