Download The anatomy of a hurricane The strength of a storm

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ä Hurricane warning
Winds at least 74 mph
ä How thunderstorm can evolve into hurricane
Cold air
Cold air
ä Storm warning
Cold air
Winds from 55 to 73 mph
ä Small craft warning
Warm air
Winds up to 38 mph
Savannah
Pensacola
Tallahassee
Jacksonville
200
Galvenston
TX
100
FL
Tampa
Corpus Christi
300
400
50
0
60
0m
0
500 mi
500 km
35°
BERMUDA
30°
Nassau
ä Category 2
25°
ä Category 3
111-130 mph
Havana
MEXICO
Eye
Minor damage to buildings. Roof damage. Trees
blown down. Possible structural damage to buildings.
CUBA
Tampico
Merida
Camaguey
Campeche
Rainbands
Guantanamo
Veracruz
CAYMAN IS.
JAMAICA
20°
HAITI DOMINICAN
REPUBLIC
Port-au-Prince
San Juan
Santo Domingo
PUERTO
RICO (U.S.)
Kingston
Belize City
Vertical flow
U.S. VIRGIN ISLANDS
Inflow
Hurricane winds
GUATEMALA
BRITISH VIRGIN IS.
ANGUILLA
ST. MARTIN
ST. BARTHELEMY
ANTIGUA
GUADELOUPE
Hurricane cross-section
EL SALVADOR
Hurricane
ä Category 4
131-155 mph
Almost total destruction of doors and windows.
Greater structural and roof damage.
DOMINICA
Puerto Cortes
15°
MARTINIQUE
HONDOURAS
NICARAGUA
Billions of gallons of water evaporate and condense, fueling the storm. Warm air in the center loses
its moisture, forming the eye. Winds reach 74 mph and the storm is reclassified as a hurricane. Average
diameter is 300 miles.
Sources: National Hurricane Center, Knight-Ridder Global Weather, National Geographic
74-95 mph
BAHAMAS
Miami
Descending air
Inflow
ä Category 1
96-110 mph
Key West
Rainbands
The National Hurricane Center classifies hurricanes
according to wind speed and destructive potential.
Larger signs and tree branches blown down. Mobile
homes at greater risk.
Vero Beach
Ft. Pierce
Port St. Lucie
Stuart
Brownsville
The strength of a storm
Signs and tree branches blown down. Mobile homes
at risk. No structural damage to buildings. Power
lines down.
.
mi
As evaporation and
condensation intensify, rising
warm air is trapped and
spreads out in all directions,
forming rainbands. Spinning,
due to the Earth's rotation,
increases and winds reach 39
mph.
70
0m
0
.
mi
The thunderstorm cluster forms
one center of low pressure and
is reclassified as a tropical
depression. Surface winds
reach 20 to 38 mph as the
storm drifts and begins to
rotate.
80
0m
Wilmington
Charleston
GA
AL
Mobile
90
0m
NC
SC
The scale is accurate along the equator.
Elsewhere on the map, scale increases toward the poles.
10
00
m
mi.
Individual thunderstorms form
as warm, moist air rises and
hits cold air. They begin to
merge into a cluster, often
reaching 100 to 300 miles in
diameter.
Baton Rouge
Gulf Port
Lake Charles
New Orleans
Tropical storm
TN
A warning is issued when a
hurricane is expected to hit an
area within 24 hours. Be
prepared to leave if an
evacuation order is issued even
though the weather does not
seem threatening at the time.
MS
MERCATOR PROJECTION
Norfolk
ä Hurricane warning
LA
Tropical depression
VA
.
mi
Thunderstorm cluster
KY
i.
Warm
air
Ocean City
.
mi
Ocean
surface
WV
i.
Warm air
Hurricane coordinates are listed by latitude (horizontal lines)
and longitude (vertical lines). The red lines on the chart
give an approximate distance from the Treasure Coast.
DE
i.
Warm air
Washington D.C.
A watch is issued when
hurricane conditions are a real
possibility and may threaten
coastal or inland areas within
36 hours.
i.
Winds from 39 to
54 mph
ä Hurricane watch
40°
Atlantic hurricane tracking chart
Atlantic City
i.
ä Gale warning
MD
ROBERT LANE staff graphic
The anatomy of a hurricane
Cold air
NJ
OH
ARUBA
SAN ANDRES
ST. LUCIA
ST. VINCENT &
THE GRENADINES
GRENADA
CURACAO
BARBADOS
ä Category 5
155+ mph
TOBAGO
COSTA RICA
100°
95°
90°
85°
TRINIDAD
COLOMBIA
PANAMA
80°
Balboa
75°
70°
VENEZUELA
65°
60°
10°
55°
50°
45°
Catastrophic damage: Buildings, roofs, structures
destroyed.
Sources: KRT, National Hurricane Center, Knight-Ridder Global
Weather, National Geographic