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A complex and wide-reaching winter storm moved from the Mid-Mississippi Valley into the Tennessee Valley on Tuesday the 13th of February, and into the Mid Atlantic and New England on the 14th and 15th of February. This strong storm produced widespread snowfall across the Mid Atlantic and New England. The heaviest hit areas were the Adirondack Mountains in New York and Northen Vermont where over 2 feet of snow fell! Across Pennsylvania totals ranged from a few inches in the far Southeast to around 20 inches in the Northeast.
The storm began to produce light snow in Southwestern PA very early Tuesday morning. The snow then spread to the north and east, becoming heavy in the afternoon.
The snow started to mix with sleet in the Southern tier of PA in the evening, and eventually turned to freezing rain over the Southeast. The upper air soundings at KLWX showed a warm (above-freezing), mid-level layer of air moving into Southern Pennsylvania causing the snow aloft to melt into rain aloft. The rain then froze into sleet as it fell through a deep layer of sub freezing air beneath the elevated warm layer aloft. (If the layer of cold air near the surface is relatively thin, then the precipitation at the surface would be rain, but it would freeze on contact with the sub-freezing ground and objects = Freezing Rain.)
The precipitation was heaviest over Central Pennsylvania Tuesday night and Wednesday morning, as the storm re-developed, and strengthened along the Mid-Atlantic Coast on Wednesday morning, prolonging the heavy snow in the North and East. Radar views at 0600, 0900, and 1200UTC show the higher reflectivity echoes transitioning from Central PA into the east as a secondary low strengthened over the eastern seaboard.
The storm produced very heavy snow across Northcentral PA, and a snow and sleet mix for the Central and Southern counties. Significant amounts of freezing rain also occurred Tuesday night and Wednesday morning in the Southeast. Harrisburg even set a daily record for the amount of (melted) liquid precipitation on Feb 14th (2.12 inches), while 6.0 inches of snow and sleet fell for the entire storm there.
The storm snarled traffic, and halted airline flights over more than a dozen States from Virginia and Maryland, where it produced lots of freezing rain and a thick coating of ice, up to interior New England, where Blizzard conditions existed on Wednesday.
This storm was the first widespread winter storm for the State during the Winter of 2006-2007. The snowfall came almost one year to the day after the last major snowfall of the winter of 2005-2006 (11-12Feb2006). Thanks to the public we received many snowfall reports which we were able to use in our Public Information Statement products. This product is helpful to emergency managers who use this information to make decisions. | 
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