What makes a storm ‘super’
by Bill Chameides | October 29th, 2012
posted by Erica Rowell (Editor)
Hurricane Sandy receives top billing of “superstorm.” Here’s why, with a look back at other superstorms.
Unless you’ve been hiding under a rock or totally obsessed about the presidential polls and what they mean, you know that a “very large and dangerous” storm is traveling up the East Coast at about 20-28 miles an hour, putting dense urban areas from D.C. to New York City on high alert; closing school systems, subways, tunnels, bridges and airports; and prompting states of emergency in at least six states and evacuations in low-lying areas. The storm is “expected to bring life-threatening storm surge and coastal hurricane winds plus heavy Appalachian snow,” reports the National Weather Service.
With the storm still some 85 miles southeast of Atlantic City, New Jersey (as of 3 p.m.), things are getting a bit sketchy. With New York Harbor closed and much of the city shut down, one New York City colleague reports that “the city has been getting increasingly eerie. The wind has been whipping up since last night, while the streets are emptying out as more stores and businesses are shuttered. And finding bottled water? Forget it. The bottled water companies made a mint in NYC alone yesterday.”
What is this storm? Among more sober meteorologists it’s called Hurricane Sandy. But it’s a lot more than just a hurricane. In a holiday-inspired spirit this monster storm has been dubbed #Frankenstorm in Twitterhood. In more staid terms, it is a superstorm.
We’re not just talking hurricane. We’re talking about a hurricane rumbling into and combining with a “winter-like low pressure trough” producing three storms in one — a tropical hurricane, a nor’easter and a potential blizzard. It’s a storm that is super-sized (NYC Major Bloomberg may have outlawed super-sized sugar drinks but he lacks the clout to ban storms).
With tropical storm-force winds stretching 700 miles from its center, Sandy’s hurricane-force winds are extending some 105 miles from its center. Satellite photos taken Sunday (see here and here) showed it reaching all the way up to Canada’s Hudson Bay.
The storm is expected to make landfall sometime this evening near Atlantic City, and reach as far inland as the Mississippi River. The storm’s worst impacts are expected in the middle Atlantic and Northeastern states where high winds, rain, snow and coastal flooding are expected.
What makes a ‘super’ storm
The term “superstorm” is not an official storm category used by the National Weather Service. It’s a relatively new name for a major storm.
According to my Google search this morning, the word first pops up in reference to the 1993 northeaster [pdf] that raged from Florida to New England in March of that year. (See also here.) By the time it was done, the ’93 storm — which stretched from Central America to Canada, affecting 23 states in the eastern United States — caused more than $3 billion in damages, cancelled 25 percent of U.S. flights for two days and killed 270 people.
Other big and super storms
“Superstorm” as a status is applied, rather refreshingly in this often hyperbolic media world, with some restraint. The January 2008 Pacific storm that hit the western United States, for instance, was considered a candidate for the term, but didn’t make the grade, according to experts at the Weather Channel.
In the “storm of the century” category, the Weather Channel’s top three U.S. storms in the 20th century are:
- the 1935 Labor Day Storm that hit Florida twice, demolishing the Florida Keys on the first pass before drenching southeast and mid-Atlantic regions,
- the 1974 Super Outbreak tornado storm referred to above (see also here) and
- the 1993 Superstorm also described above.
One feature of the superstorms, as the National Oceanic and Atmospheric Administration makes note of, is powerful storm surges. Two of the rare super storms are included in its list of the nine events with the biggest storm surges and inundations.
Storm surge is expected to be a major problem with Hurricane Sandy and a full moon — a time when tides can become unusually high — could make things worse. New York City officials are hoping that the storm arrives before high tide this evening to avoid the tallest possible waves crashing ashore.
The next few days will tell whether Sandy will become a 21st-century storm of the century … well until the next one comes along.
filed under: faculty, weather
and: Frankenstorm, Hurricane Sandy, hurricanes, rain, storms, superstorm