HURRICANES – NATURE’S FURY!!!
Check these out…
You’d probably want to evacuate at
this point…
What kind of damage are we talkin’ about here?
Might want to take the detour…
Ok, So What Exactly Is a Hurricane?
A hurricane can best be
described as a huge
tropical storm (up to 600
miles in diameter)!
Winds can be up to 200
mph!
Storms usually doesn’t
last for more than 7-10
days.
It moves across the ocean
at around 10-20 mph…not
too fast really!
Arrows indicate
“feeder bands”
or “rain bands”
The winds are the strongest around the eye
wall. The eye of the storm is usually about
20 miles in diameter. Within the eye, winds
are calm and the weather is great.
Strongest winds are on the right side,
heaviest rain is usually on the left side.
Scary…so when do I need to watch out for these things??
Since we’re in the USA, we’ll focus on what meteorologists call the “Atlantic Basin”.
The Atlantic basin includes the Atlantic Ocean, Caribbean Sea, and the Gulf of
Mexico.
The “hurricane
season” is just a
name for the time
period when we
expect to see
tropical systems
develop. The
hurricane season
for the Atlantic
runs from June 1st
– November 30th.
Peak season is the middle part of September…why
do you think this is?
So where are these “Atlantic Basin” Hurricanes forming???
Storms of the Atlantic
basin will begin forming
in one of three places:
• Off the coast of Africa
• In the Caribbean Sea
• In the Gulf of Mexico
What is the
ITCZ????
Intertropical Convergence Zone
The ITCZ is an
area of low
pressure located
roughly 5 degrees
North and South
of the Equator. It
is a place where
air converges,
rises, and
condenses
(forming clouds).
It is the rainiest
place on Earth!
What Does a Hurricane Need in Order to Develop?
A hurricane needs warm water, time to grow, and favorable upper
level winds in the troposphere. If the winds are too strong, they will
blow the hurricane apart – we call that wind shear!
Evolution of Hurricane Development -- Stages
Stage 1 – Tropical Depression(Wave)
Usually has begun its life off of the west coast of Africa in the ITCZ.
Tropical depressions have winds of less than 39mph, and are not given a
name.
Lacks structure – no
well developed
feeder bands or eye
Evolution of Hurricane Development -- Stages
Stage 2 – Tropical Storm
At this point, the tropical storm is beginning to develop some serious
structure. Winds range from 40-73 mph. In the Atlantic, storms are given
a name when they reach this stage.
Feeder bands are
beginning to develop
– you can see the
center of the low
pressure system
more easily. Eye and
eye wall still not well
formed.
Evolution of Hurricane Development -- Stages
Stage 3 – Category 1 Hurricane
Winds range from 75-94 mph.
Well developed
feeder bands. An
eye begins to form
(although it is
covered in clouds).
Storm is tightening
around center.
Evolution of Hurricane Development -- Stages
Stage 4 – Category 2 Hurricane
Winds range from 95-110 mph.
Well developed
feeder bands. An
eye and eye wall are
usually very well
formed. Storm
continues to tighten
around center.
Evolution of Hurricane Development -- Stages
Stage 5 – Category 3 Hurricane
Winds range from 111-130 mph.
Now considered a
“Major Storm”.
Intense flooding and
building damage will
occur to most areas
on the coast. Further
inland, the damage
will still be
substantial.
Evolution of Hurricane Development -- Stages
Stage 6 – Category 4 Hurricane
Winds range from 131-155 mph.
Shrubs, signs and trees
can be blown down.
COMPLETE
DESTRUCTION of
mobile homes is
possible. Extensive
damage to doors and
windows. Major damage
to lower floors of
structures near the
coast.
Evolution of Hurricane Development -- Stages
Stage 7 – Category 5 Hurricane
Winds greater than 156 mph!
Complete roof failure on
many residential and
industrial buildings.
Some complete building
failures with small
utility buildings blown
over or away.
Massive evacuation of
residential areas on low
ground within 5-10
miles of the coastline
maybe required.
Saffir-Simpson Scale of Hurricane Intensity
Hurricane Naming System – Why do they have names anyway?
•In 1953 the National Weather
Service began naming storms after
women.
•In 1979, men’s names were added
to the list of hurricane names.
• In the Atlantic, there are 6 lists of
names that are recycled.
• In the case of storms so devastating
that reusing the name is
inappropriate, the name is taken off
the list and another name is used to
replace it. The name “Katrina” is one
that will be removed from the list.
Example LIST:
Andrea
Barry
Chantal
Dean
Erin
Felix
Gabrielle
Humberto
Ingrid
Jerry
Karen
Lorenzo
Melissa
Noel
Olga
Pablo
Rebekah
Sebastien
Tanya
Van
Wendy
More cool stuff to check out…
Aftermath…
Aftermath…
Aftermath…
Aftermath…