Public Information Statement
Issued by NWS Caribou, ME

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12

NOUS41 KCAR 170946

Public Information Statement
National Weather Service Caribou ME
546 AM EDT Mon Jul 17 2017

The National Weather Service has declared the week of July 17th
through 21st, Hurricane Preparedness Week in Maine.  This is the
first in a series of five public information statements to be issued
by the National Weather Service Office in Caribou, ME containing
information on Hurricanes and Hurricane Preparedness.


The term "tropical cyclone" is a generic name given to a low
pressure system that generally forms in the tropics and is
accompanied by showers and thunderstorms and a counterclockwise wind
circulation.  Depending on the strength of the winds in the
circulation, tropical cyclones are further divided into tropical
depressions, tropical storms, and hurricanes.

The tropical cyclones that affect eastern North America generally
form in either the tropical Atlantic Ocean, the Caribbean Sea, or in
the Gulf of Mexico.  The three main conditions which favor tropical
cyclone development are (1) warm ocean waters, (2) atmospheric
moisture, and (3) relatively light winds aloft.  In addition, an
atmospheric disturbance, called a tropical wave, is needed to
initiate the development of the counter-clockwise wind
circulation. If the favorable conditions persist for a sufficient
amount of time, the tropical disturbance can strengthen to a
in a tropical cyclone reach tropical storm strength (39 mph, 34
kt), the storm is "named". Tropical cyclones are classified as

Tropical Cyclone Terms:

Tropical Depression - An organized system of clouds and
thunderstorms with a defined surface circulation and maximum
sustained winds of 38 mph (33 knots) or less.

Tropical Storm - An organized system of strong thunderstorms with a
defined surface circulation and maximum sustained winds of 39-73 mph
(34-63 knots).

Hurricane - An intense tropical weather system of strong
thunderstorms with a well-defined surface circulation and maximum
sustained winds of 74 mph (64 knots) or higher. Hurricanes are also
classified into different categories based on strength.

Tropical Cyclone Description:

The well-developed hurricane consists of an eye, an eyewall, and
spiral bands of showers and thunderstorms.  In the eye, winds are
relatively calm and there is a gentle sinking motion in the
atmosphere which leads to mostly clear skies. Surrounding the eye
is the eyewall which contains the most violent winds, the most
intense showers and thunderstorms in the hurricane, and can
contain tornadoes. The winds in the eyewall also have the greatest
potential for causing a deadly storm surge. Outside the eyewall,
spiral bands of showers and thunderstorms rotate around the storm.
These bands of showers and thunderstorms can also be very
intense, can move into an area very rapidly, and are the most
likely area in the hurricane for tornadoes to form.

Tropical Cyclone Threats:

Hurricanes and tropical storms bring with them four main threats:
high winds, coastal storm surge, inland fresh water flooding, and
tornadoes.  These will be discussed in greater detail in forthcoming

While hurricane season lasts from June through November, the peak of
the season is from mid-August through October.  Each year, an
average of ten tropical storms develop over the Atlantic Ocean,
Caribbean Sea, and Gulf of Mexico. Many of these storms remain over
the ocean, and an average of six of these storms become hurricanes
each year.  During an average 3-year period, roughly five hurricanes
strike the United States coastline, killing approximately 45 people
(an average of 15.5 per year) anywhere from Texas to Maine. Of
these, two are typically "major" or "intense" hurricanes (winds
greater than 110 mph).

Now is the time to prepare for Hurricanes and Tropical Storms:

$$ is the U.S. government's official web portal to all federal, state and local government web resources and services.