- Education and Science
Photos of the Connecticut Groundhog Day Ice Storm of 2011
After dealing with what seemed to be endless train of snowstorm after snowstorm in the month of January 2011, there were signs of the winter thaw showing up. However, the deep snow pack of January left the air close to the ground a little too cold. This shallow layer of cold air resulted in freezing rain and an ice storm. Ironically, this occurred on Groundhog Day of all days, when many look for the glimpse of hope that winter is almost over, and we ended up with an ice storm.
The ice storm was unusual because living near long island sound, a maritime influence usually warms that shallow layer of air just enough to turn any brief periods of freezing rain to just all rain. In addition the topography of the area allows warm air to inundate coastal towns fairly easily. So on February 2nd when all but one or two hours was freezing rain and sleet which accumulated on streets, sidewalks, driveways, on top of the snow, on homes and trees, it was a surprise. Even when it rained for a few hours, some of the rain would form ponds on the ice and then refreeze later.
What was also strange about this storm is the amount of time the ice stuck around. The ice on the trees lasted for days, which actually made for a beautiful sight, especially with the clear skies the day after the storm. Looking around everything was glistening in the sun up and down streets, creating a winter wonderland look. This ice storm just added to the pain of the extreme winter of 2011 but was also one of the last large winter storms to hit the area for the season. Following the storm there was no winter thaw but a gradual, almost painful, warm up to spring.
Above is a graphic I made using the weather surface map for February 2, 2011 (provided by NOAA). There were many players in the game that created the perfect conditions for an ice storm along the Connecticut shore. From the strong high pressure to the north sending cold air down into New England (creating cold air damning) to the secondary low pressure forming along the Delmarva coast and the deep snowpack aiding in the freezing conditions.
New England generally receives three different types of snow storms. These include nor'easters (coastal storms, blizzards), Great lake cutters (inland, warm storms) and Alberta Clippers (weaker, cold storms). Of course there are many variations in between but these three scenarios give Connecticut different weather outcomes. If the storm is off the east coast, it can result in blizzard conditions and a hefty amount of snow, if it's an Alberta Clipper there's usually a small amount of snow and if it's a Great Lakes Cutter it usually means rain.
The storm on February second was a combination of a Great Lakes Cutter and a Coastal storm. The original storm's low pressure can be seen in the graphic over Indiana. If there was no high pressure to the north of New England, this storm would have gone straight up through the Great Lakes ushering in warmth to the east of it (here in Connecticut). This would have resulted in a storm that would have started as snow, turned to a brief mix before going over to heavy rain. However, the high pressure was in the way, so the low transferred it's energy to a new low pressure around the Delmarva, creating a coastal storm and providing another piece of the puzzle that locked in the cold air. Combine this with the deep snowpack on the ground, creating a shallow layer of cold air at the surface, the north wind from the high pressure locking in cold air at the surface and warmer air aloft being pushed north by the orgiinal low pressure system and you have the perfect conditions for Freezing Rain.
Freezing rain like sleet, is all dependent on the temperature layers in the atmosphere. To get freezing rain, all layers of the atmosphere are above freezing except for the surface or the layer of air just above the surface (usually only a few meters high). This set up allows rain to form and fall without freezing until it hits the surface, creating a glaze of ice that accumulates over time. This results in everything being covered in a sheet of ice, making for a beautiful scene but a dangerous landscape.