|
Historical Tropical Cyclone Tracks |
What this map layer shows:
The paths of tropical cyclones and major hurricanes from 1851 to 2004.
|
|
Background Information |
Sample Map
The term "tropical cyclone" is a generic term for a low-pressure
storm system that usually forms in the tropics. The unpredictable
behavior, high seas, and devastating winds of tropical storms have
challenged us for centuries. One of our best defenses against hurricanes
and other tropical storms is informed readiness. The National
Hurricane Center (NHC), part of the National
Oceanic and Atmospheric Administration,
National Weather Service (NWS), collects tropical cyclone data as
part of its mission to save lives and mitigate property loss by issuing
advisories of hazardous tropical weather. The NHC tracks hurricanes
and other tropical cyclones over the Atlantic, Caribbean, Gulf of
Mexico, and Eastern Pacific and issues hurricane forecasts, watches,
and warnings to the public. Computer models are used to forecast the
track and intensity of a tropical storm. These statistical models use
current information about a storm and compare it with historical knowledge
about the behavior of similar tropical storms. The historical record
for storms over the North Atlantic begins in 1851, and the record in
the Pacific begins in 1949.
Tropical storms are classified by wind speed and by the structure
of the storm and include hurricanes, other tropical cyclones, subtropical
cyclones, and related storms. The highest intensity storms, with the
highest wind speeds, are hurricanes. Lower intensity storms have lower
wind speeds and may not exhibit the convection and circulation properties
found in hurricanes. Lower intensity storms can sometimes inflict greater
damage than storms of higher intensity, depending on where they strike
and the particular hazards they bring.
A tropical cyclone is a warm-core, non-frontal low-pressure system
that develops over tropical or subtropical waters, covering a large
region and with organized convection (i.e. thunderstorm activity) and
definite cyclonic (counter-clockwise circular) surface wind circulation.
Examples are hurricanes, tropical depressions, and tropical storms.
A subtropical cyclone, such as a subtropical depression or storm, is
a low pressure system that develops over subtropical waters and that
initially has a non-tropical circulation but in which some elements
of tropical cyclone cloud structure are present. Subtropical cyclones
can evolve into tropical cyclones. Related storms are those that develop
into subtropical or tropical cyclones or develop from them, such as
tropical disturbances, lows, waves, and extratropical storms.
The National Atlas offers three map layers showing tropical storm
tracks. These map layers were produced by the National Atlas of
the United States® from data provided by the
NHC. The Historical North Atlantic Tropical Cyclone Tracks, 1851-2004
map layer shows the paths of all recognized tropical cyclones in
the North Atlantic from 1851 to 2004. The Historical North Atlantic Hurricane
Tracks - Major Storms with Landfall in the United States, 1851-2004
map layer includes only the major storms from 1851 to 2004. Major storms
are those that made landfall in the United States and that were classified
on the Saffir-Simpson
Hurricane Scale as Category 3, 4, or 5 at the
time of landfall. Landfalling storms are defined as those storms whose
center is reported to have either crossed or passed directly adjacent
to the United States coastline, and which came ashore with tropical storm
intensity or greater (sustained surface winds of 34 knots or 39 miles
per hour or greater). The Historical Eastern North Pacific Tropical Cyclone
Tracks, 1949-2004 map layer shows the paths of all recognized tropical
cyclones in the eastern North Pacific from 1949 to 2004. Points defining
the storm tracks were recorded every six hours. For each recorded point
on a track, there is descriptive information which includes the storm
location in geographic coordinates, the storm name, the storm intensity
according to the Saffir-Simpson Hurricane Scale, wind speed, and barometric
pressure.
For answers to questions on tropical cyclones, visit the NOAA Atlantic
Oceanographic and Meteorological Laboratory, Hurricane
Research Division (HRD), Hurricane
FAQ page. The NHC Hurricane
Preparedness page and
the NWS Hurricane
Awareness page also have detailed additional information
about hurricanes and tropical storms. HRD offers a page with lists
of names used for tropical storms around the world. |
|
|
|
|
|
|
|