Hurricane Saftety Awareness Week - Monday

The National Weather Service has declared the week of July 15th
through 19th HURRICANE SAFETY AWARENESS WEEK in New England.
This is the first in a series of five public information
statements to be issued by the National Weather Service Office
in Gray containing information on hurricanes and hurricane safety.

TROPICAL CYCLONES, TROPICAL STORMS AND HURRICANES--THE BASICS

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
the Gulf of Mexico. The three main conditions which favor
tropical cyclone development are (1) warm ocean waters,
(2) abundant 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 TROPICAL DEPRESSION, TROPICAL STORM, or HURRICANE. When the
winds in a tropical cyclone reach tropical storm strength
(39 mph, 34 knots), the storm is "named". Tropical cyclones are
classified as follows:

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.

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, 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.  

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
statements.

While hurricane season lasts from June through November, the peak of
the season is from mid-August through October. Each year, an average of
twelve 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 (sustained winds greater than 110 mph).

QUESTION OF THE DAY:  How are hurricanes named and what names will be
used in 2019?  

Women's names were first used to name tropical storms and hurricanes
during World War II, with some variations in practices in the
early 1950s. In 1953, the U.S. Weather Bureau began using a
standardized list of female names in naming Atlantic tropical storms
and hurricanes. The practice of using female names exclusively ended in
1979 when both male and female names were included in lists for the
Atlantic and Gulf of Mexico hurricane lists. The name lists are agreed
upon at international meetings of the World Meteorological Organization.
The names alternate between male and female names and have an
international flavor because hurricanes affect other nations and are
tracked by the public and weather services of many countries.
 
There are currently six lists of names used in naming hurricanes;
a different list is used each year. The lists are repeated in 6-year
cycles. However, names associated with storms that have caused
significant death and/or damage are usually retired from the list and a
replacement name is selected by the World Meteorological Organization.

Below is the list of names that have been or will be used for 2019.

Andrea     Barry      Chantal    Dorian     Erin       Fernand
Gabrielle  Humberto   Imelda     Jerry      Karen      Lorenzo
Melissa    Nestor     Olga       Pablo      Rebekah    Sebastien
Tanya      Van        Wendy

Note that the letters Q, U, X, Y, and Z are not used in the list.

FACT FOR THE DAY: The name hurricane is derived from the Caribbean
storm god, Juracan.

Here's a list of topics to be covered later this week:

Tuesday - Hurricane Winds and Tornadoes
Wednesday - Storm Surge and Marine Safety
Thursday - Inland Flooding
Friday - The Forecast Process--Statements, Watches, and Warnings

For additional information about hurricanes and hurricane
safety, visit the National Hurricane Center's web site at:

               http://www.nhc.noaa.gov/

$$
 
Watson
National Weather Service
Gray...Maine
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