December, 2003 has kept our shovels busy and our rivers running high.
Several large winter storms dropped as much as 5 feet of snow in one week over much of the interior of Maine. This remarkable snowfall, however, has been eroded away by several large rain storms.
The overall weather patterns in December featured two predominant storm tracks. The first being the classic Nor'easter track, with upper-level energy swinging into the Southeast spawning a coastal low which then moves up the coast toward New England. The second being a 'warm track' which featured two major storms tracking through western New York. This pattern eventually brings warm air in at all levels of the atmosphere. Freezing rain occurs often with this track due to cold air damming.
The result of the two major snowstorms staggered with two major rain storms is major flooding. Canton, Maine was overwhelmed with river water after the tremendous snowpack melted under warmer temperatures and rain water. The relatively thin river ice sheets were broken up and caused many ice jams around the region, including Farmington, Maine and Plymouth, New Hampshire. Several students' cars at PSU were flooded out and severely damaged by the Pemigewasset river.
The contrast between Christmas weather this year and Christmas last year is quite interesting. Last year, of course, was the December Blizzard- at WeatherMaine in South Portland, over 19 inches of snow was received during this event. This year's weather was that of rain and fog, a far-cry from the digging out of last year. The fog during Christmas eve night was very thick, and was the result of warm, moist air moving over our snowpack. The cold surface snow and ice cools the air near the surface. Since the amount of water the air can hold depends directly on its temperature, colder air can hold less water. As the air cools near the ground, it becomes saturated- like a towel than can hold no more water. This results in fog. There are complex processes involved with fog over snow, but it is mostly seen during 'warm track' storms in the winter.
