Subscribe for free email updates . Click here to sign up, or log in . As a meteorological event - not very. Yet real-life experts suggest the 1991 storm may be a victim of Hollywood hype. However, this is true for any major storm.
Case describes the situation as follows.
The high-pressure system, originating in northern Canada, provided a large pool of cold air. A weak low-pressure system was moving along the front. The cold air behind the front and warm air ahead of it caused a strong temperature contrast to form over a relatively small area. Such a sharp temperature change caused the low to rapidly intensify. A third ingredient, Case says, was the addition of lots of moisture from Hurricane Grace, which had gotten caught up into the Nor'easter's large circulation.