•        Hurricanes pose the greatest risk for a widespread natural disaster in the Mid-Atlantic region during
    the months of August, September and October.

  •        The East Coast is in an active hurricane cycle, which began in 1995. Active cycles typically last 25 to
    30 years. Past patterns along the East Coast suggest several notable storms strike during a four or five
    year period, in tandem with a less active time lasting several years. (The 2004 through 2010 seasons
    were generally tranquil, with a nearly total absence of hurricanes making landfall between Georgia and
    Maine.)

  •        The Middle Atlantic states have well-defined cycles of increased hurricane activity. It's as if someone
    turns on or off a faucet. Previous active cycles in the region occurred from 1876 until 1904 and from 1933
    until 1961.The period from 1969 until 1979 brought the Mid-Atlantic several notable hurricane-related
    floods, although that timeframe is considered less active in the North Atlantic. (Sometimes, the Mid-
    Atlantic region seems to march to its own drummer.)

  •        The region's climate is highly cyclical. Extremes are often followed by extremes. A drought, for
    example, may be followed by a hurricane-related flood. A period of years with little widespread severe
    storm activity is often followed by two or three years with several destructive storms affecting large
    sections of the Mid-Atlantic. These may include hurricanes and winter nor'easters.

  •         Although August, September and October are often regarded as the peak of the hurricane season,
    the Middle Atlantic states have not experienced a significant October hurricane since Hazel in 1954.
    Before then, destructive October hurricanes tended to batter the region once or twice each decade and
    October's monsters--hurricanes and nor'easters--were part of local lore.

  •        Hurricanes that occur within a month or two of each other, in the same general geographic vicinity,
    often take roughly parallel tracks.      

  •        Coastal sections are due for a destructive hurricane. Hurricane Gloria in 1985 was the last to cause
    modest to significant losses to all Mid-Atlantic shore areas, from Virginia to Long Island, New York. The
    Great Atlantic Hurricane of 1944 was the last to cause severe damage along the shoreline from Virginia
    to New Jersey. The Mid-Atlantic coast has had a dearth of major coastal hurricanes since the early
    1960s. Similar quiet periods occurred from the late 1820s until the late 1870s, and for about three
    decades during the early years of the 20th century. These less active periods were followed by many
    violent hurricanes, six or more within 25 years.

  •        On rare occasions, intense hurricanes (Category 3 or stronger at landfall in North Carolina or while
    off the Mid-Atlantic coast) have produced a massive wave or series of waves described by those on
    shore as appearing like "tidal waves." These caused immense damage to buildings and other
    structures along the shoreline. Generally, the storm waves quickly lost momentum and losses were
    limited to sections within a block or two of the beach. Such events have occurred along sections of the
    Mid-Atlantic coast in 1821, 1878, 1938, 1944 and, perhaps, at other times. The huge waves struck as the
    center of the storm made its closest passage, as easterly winds turned westerly.

  •        Interior sections are due for a highly destructive hurricane-related windstorm. Hurricane Hazel in
    1954 was the last tropical cyclone to carry actual hurricane force (74 mph and greater) winds through a
    large section of the Mid-Atlantic interior, from Virginia to Pennsylvania. The region's climatological  
    history suggests that inland hurricanes such as Hazel occur about twice each century. Similar events
    occurred in 1667, 1724, 1769, 1775, 1821, 1878 and 1896. Highly destructive winds generally ranged
    roughly east-west in a 50 to 100 mile band in the storm's northeastern sector, although a brief period of
    higher winds sometimes occurred after the center's passage, when winds turned westerly.

  •        The popular Saffir-Simpson hurricane intensity scale understates the potential for wind damage in
    the Mid-Atlantic region. A Category 1 hurricane (sustained one-minute winds of 74-95 mph) can be
    expected to do widespread Category 2 and 3-type damage. Isolated areas may see Category 4-type
    losses. Leafy trees and other vegetation, less wind-resistant structures and infrastructure, as well as,
    perhaps, other yet to be identified factors are responsible for the region's wind susceptibility. Also, Saffir-
    Simpson estimates of tidal surge, particular in the Chesapeake Bay region, seem understated based
    on observations during Hurricane Isabel.

  •        Rapidly advancing hurricanes, those with forward speeds greater than 30 mph, seem to have a
    greater ability to deflect higher winds aloft down to the surface, mainly in the northeastern sector (when
    the storm is tracking in a northerly direction).  The strongest winds are location specific. As described by
    an observer in Washington, DC., after the great windstorm of September 1896, "In hundreds of
    instances a well constructed roof, rafters and all, was blown off, while close by very frail structures at the
    same height were uninjured." Any Category 3 or stronger hurricane making landfall from the Carolinas
    on north and accelerating above 30 mph threatens destructive winds well inland.

  •        'Major' hurricane Mid-Atlantic style: Meteorologists define a 'major' hurricane as possessing at least
    Category 3 strength (sustained winds of at least 111 mph). Because of the Middle Atlantic states'
    susceptibility to wind damage, a Category 1 hurricane (sustained winds of 74-95 mph) tracking through
    interior sections will cause major destruction. Furthermore, a tropical cyclone that stalls off the Mid-
    Atlantic coast for more than a day may produce major shoreline damage even if it is something less
    than a Category 3.

  •        Tropical cyclones bring great differences in rainfall and wind speeds over short distances. Tropical
    Storm Hanna (Sept 2008), for example, dumped less than two inches of rain to more than eight inches
    in the Washington, D.C., metropolitan area. Hurricane Isabel (Sept. 2003) lashed Washington and its
    suburbs with peak gusts ranging from less than 50 mph to nearly 80 mph. (Higher winds aloft reached
    the surface unevenly.)

  •        When evaluating the severe weather risk associated with a hurricane, it is important to consider the
    possibility of violent storms in the air mass ahead of the tropical cyclone, in adjacent weather systems,
    and in the air mass behind. The worst weather may occur indirectly, outside the hurricane's circulation,
    sometimes days before or after. Tropical Storm Nicole in 2010 is an example, as huge rainfall occurred
    in the tropical flow that was only partially part of Nicole. In September 2011, Tropical Storm Lee
    disintegrated as an organized weather system soon after landfall in September 2011. Its remnants
    merged with other weather features to produce catastrophic flooding in part of the Mid-Atlantic region.

  •        The Mid-Atlantic region boasts some of the most intense short-term downpours on earth. A few are
    related to tropical cyclones. The intense rainfall does not necessarily correlate to elevation. Hurricane
    Camille, for example, dumped more than 27 inches of rain on sections of Nelson County, Virginia, within
    about five hours in August 1969. Thunderstorms stalled by a hurricane off the New Jersey coast
    bucketed Ewan, New Jersey, (just 20 miles south of Philadelphia) with more than 22 inches in about 10
    hours during September 1940. (While Nelson County is mountainous, Ewan is nearly at sea level.)

  •        On rare occasions, for unknown reasons, remnant hurricane systems have regenerated while their
    centers of circulation were over land. All such incidents have been heralded by a surge in rainfall
    intensity, resulting in generalized and flash flooding. Some examples include the Great Labor Day
    Hurricane of 1935 and hurricanes Cleo (1964), Camille (1969), Agnes (1972) and Gaston (2004).

  •        A hurricane deluge is of particular concern in mountainous areas. Steep slopes in mountainous
    sections allow rapid runoff. An extreme event, such as occurred with Hurricane Camille, can liquefy the
    soil generating deadly mud flows. Meanwhile, Mid-Atlantic urban sections, often situated on hilly terrain,
    are at risk of flash flooding. Concrete, asphalt and other impervious surfaces reduce the absorption of
    rainwater, increasing runoff. The monsoonal downpours of a tropical cyclone can quickly turn destructive
    and deadly, as occurred with Hurricane Gaston in 2004 when it pounded the Richmond, Virginia., metro
    area with rainfall totals that topped 10 inches.

  •        Remnant systems tracking through the Mid-Atlantic region may spawn tornadoes, particularly in the
    northeastern sector (if tracking in a northerly direction). They are generally short-lived, with intermittent
    tracks usually less than five miles. Pinpointing where a tornado will touch down is beyond our present
    knowledge. Although most have occurred during daylight, a considerable number have prowled at night.



         Jay Mann of Long Beach Island, New Jersey, minces no words when discussing hurricanes and rip currents.

         “Rip currents are insidious,” said Mann, a long-time resident of the shore and rip current expert. “People
    caught in strong rips like those produced by a hurricane are amazed by how quickly they find themselves in
    deeper water, well away from the beach.”

          During the past half-century more people have died in the Middle Atlantic states from hurricanes whose
    circulation never reached shore than from those that pummeled the coast. Sprawling hurricanes can produce
    groundswells that travel out a thousand miles or more. Even during a summer when tropical cyclones give the
    East Coast a wide berth, beach-goers can expect periods when venturing into the ocean is treacherous.

          “There’s almost a 100 percent chance we will be affected by hurricane swells this summer,” Mann said, “and
    less than a 10 percent chance we will get hit by a hurricane.”

          Rip currents are powerful, channeled currents of water flowing away from the shore. They typically extend
    from the shoreline, through the surf zone, and past the lines of breaking waves. Rips are usually caused by
    onshore winds and associated surf or by the interaction of the ocean and man-made structures like jetties, but
    hurricane swells are the most potent rip generators.

         Several factors make hurricane-related rip currents deceptively treacherous.

         The strength and number of hurricanes generally peak during the summer when shore areas are crowded.
    Vacationers can’t wait to plunge into the inviting ocean under a warm summer sun. A hurricane hundreds of miles
    at sea, perhaps no threat to strike the Middle Atlantic coast, is usually out of sight and mind. It does not get the
    media attention of an oncoming storm. The public associates hurricane threats with hurricane circulation. Rip-
    producing swells spread over a much greater area.

         A groundswell may be miles long as it approaches shore but not particularly high. Unless the swells encounter
    winds near shore, they may not have foaming whitecaps. Nevertheless, a three-foot high hurricane-related
    groundswell carries more power, energy and water than a similarly-sized normal wave.

          “Hurricane swells are the survivors of a hurricane’s strongest waves,” said Mann. “They are the most powerful
    waves and important developer of rip currents out there.”

          The large volume of water crashing on shore means a large volume returning to sea. Even excellent
    swimmers have drowned when caught in the return flow.

          Hurricane generated waves may arrive in groups separated by minutes of innocuous, local waves. A swimmer
    venturing into the surf during a lull can quickly get into trouble once a series of groundswells arrive.

          Adding to the threat: Many people, unfamiliar with the ways of the ocean or, simply misjudging their swimming
    ability, have no experience dealing with rip currents. Unable to make progress back to shore and uncertain why,
    they panic and quickly tire.

         “You can’t believe how many people have drowned because they did not raise their hands over their heads or
    in other ways signal for attention,” Mann said. “I tell people, ‘If you’re caught in a rip and have a question about
    whether you can get back to shore, don’t wait until you’re exhausted. As soon as you feel yourself in a bind, forget
    about the embarrassment factor and start signaling for help.”

         The National Weather Service offices that forecast for coastal sections issue rip current advisories using a
    scaled likelihood of low, medium or high. There are also “enhanced risk” warnings. These typically accompany
    hurricane-related swells and indicate a greater likelihood of particularly powerful rip currents.

         Jim Eberwine, the rip current specialist at the National Weather Service office in Mt. Holly, N.J., works with
    information from coastal observers such as Mann, monitors buoy data and analyzes weather features to create
    daily rip current outlooks for New Jersey and Delaware during the late spring and summer. Hurricanes create a
    special challenge.

         “We want to issue something that warns of serious conditions in the water but does not scare people away
    from the beach,” said Eberwine.

         He has observed the deadly effects of obscure hurricanes that remained well offshore. Felix, for example,
    remained hundreds of miles away from land as it meandered off the U.S. East Coast in 1995, but produced rip
    currents that drowned more than a dozen swimmers.

          “Rip currents are a sneaky part of the storm that many people aren’t aware of until it’s too late,” said
    Eberwine, who describes the rips as “a treadmill that you can’t turn off.”

          His advice to beach goers: “A rip current savvy person is one that checks with the beach patrols about the
    conditions, swims on guarded beaches and never alone or at night.”

         Eberwine added, “The worst thing is a family of six coming to the beach and going home a family of five.”

         For more information on rip currents, visit www.ripcurrents.noaa.gov.
Rip Currents Are A Hurricane’s Hidden Menace
Regional hurricane history indicates definite characteristics and patterns. The book
Hurricanes and the Middle Atlantic States includes the following observations: