What is a nor'easter and how does it differ from a hurricane?
Posted September 27, 2008
MIKE MOSS SAYS: Paul, A classic Nor'easter is an extratropical cyclone that produces strong northeasterly winds along the east coast of the United States, while a hurricane is a fully tropical cyclone having some notably different organizational and life cycle characteristics. However, strong low pressure systems actually exist along a continuum that may include characteristics of both extratropical and tropical systems, sometimes making the designation of a particular storm more complicated than it might first seem. You can read more about the differences in extratropical and tropical cyclones, and the subtropical or "hybrid" storms that are neither fully one nor the other, in a previous post at
Regarding the storm that affected the North Carolina coast during the past few days before moving inland, across South Carolina and into the western parts of our state, it initially formed on a recently stalled frontal boundary and under the influence of a deepening upper level low, and with temperatures near the center that were colder than surroundings at most altitudes, all typical of extratropical lows. However, by the time it finally moved ashore, the frontal zone was becoming diffuse, the storm was developing discrete inflow/convective rain bands, and some of the last reconnaissance flight readings began to show a possible warm-core structure. Had the system been a little farther from land or spent more time stalled over warm water, it may very well have been designated a tropical or subtropical storm and given a name, and it was probably a close call on the part of the National Hurricane Center as to whether to do so or not in the hours before it pushed ashore.