Two good examples are the nor'easter's in 1982 and 2003. 1982 was a very rare event that left NYC with 10 inches of snow and parts of NY state with over 2 feet! Winds reached 60 mph, and power was out everywhere. It set many records in many places including Newark which received 13 inches of snow and then the next day set a record low of 19 degrees in the morning.
April 6th, 1982
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The other example is April 2003, where 5-8 inches of heavy wet snow fell across the NJ area.
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Will this go down on the list of rare April snowstorms? I would say at this point, yes. Reason being, models are actually coming to a somewhat fair consensus that I-95, or parts of I-95, may be in for a snow event. In fact, if everything goes "perfectly", this certainly has the potential to be a historical storm. This is my current thinking on the storm in terms of totals, but I'm sure a lot will have to be shifted and moved around.
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Keep tune, for change is likely with this system; beware.
-Scott Pecoriello