It mainly depends on the strengthof its winds.
"The term "storm" refers to both the geographic origin of these systems, which form almost exclusively in tropical regions of the globe, and their formation in Maritime Tropical air masses. The term "cyclone" refers to such storms' cyclonic nature, with counterclockwise rotation in the Northern Hemisphere and clockwise rotation in the Southern Hemisphere."
http://en.wikipedia.org/wiki/Tropical_storm
This site cites winds in such a storm as having a speed over 74 mph to qualify as a hurricane.
"While all are large storms of tropical nature, their official storm name has to do with its wind speeds.
When the storms are in their infant stages as just a general area of low pressure that has the potential to strengthen, they're usually given the name "Tropical Depression"
If the storm's peak winds become greater than 39 mph, then it's now a "storm" and it gets a real name from the National Hurricane Center, like "Tropical Storm Barry."
...If the storm continues to grow and reaches wind speeds over 74 mph, it's then a hurricane"
http://www.komonews.com/weather/asksteve/4347506.HTML
A tropical storm begins to brew over the ocean. As it makes contact with warm ocean waters - if the temperature of the water is above 26.5 degrees Celsius (80 Fahrenheit) - the storm's heat and energy intensify. Winds rotate counterclockwise around a calm center (the "eye"). When the sustained speed of the winds reaches 74 mi (119 km) per hour, the storm is officially classified as a hurricane.
The weather bureaus declare a hurricane watch when a tropical storm intensifies, and it becomes likely that a hurricane will develop within 24-36 hours. A hurricane warning is issued when hurricane conditions are expected in 24 hours or less. The severity of a hurricane in terms of its intensity is measured by the Saffir-Simpson Scale, on a scale of 1-5, with 5 being the most severe. The hurricane is ranked by its wind speed. The scale helps to estimate the amount and type of damage expected from the storm.
Such a storm is called a hurricane.
As of 2016 there has been a Hurricane Matthew, which briefly became a category 5. So far no storm has been named Courtney.
"Hurricane" Zeta was never a hurricane, just a tropical storm. There were no deaths from Tropical Storm Zeta.
hurricane is the biggest type of storm
a hurricane remains a hurricane when the hurricane is 74 miles and up, if it is lower, its downgraded into a tropical storm.
Fiona is not a hurricane, but a tropical storm. The storm became a tropical cyclone on August 30, 2010.
Tropical Storm Rita became Hurricane Rita on September 20, 2005.
Pablo never became a hurricane. It was only ever a tropical storm.
he started as a tropical depression, then he became a tropical storm, then BAM! hurricane...!
Allison was a tropical storm and never became a Hurricane. At peak intensity Tropical Storm Allison had winds of 60 mph. A storm needs winds of at least 74 mph to be a hurricane.
Fay never became a hurricane. It was a tropical storm that fell just short of hurricane status
it started as a tropical disturbance at first, then it became a tropical depression, and a tropical storm, then a hurricane.
Interestingly, the storm Known as Allison never became a hurricane, but peaked as tropical storm with 60 mph winds. A storm must have winds of at least 74 mph to be a hurricane. Despite not being a very strong storm, Allison produce heavy flooding from from rain. It is the only Atlantic storm to have its name retire that did not become a hurricane.
Andrea never became a hurricane but remained as a subtropical storm. This storm ever made landfall but its outer bands affected Virginia, the Carolinas, Georgia, and Florida.
Tropical Storm Zeta never became a hurricane. It did not result in any known fatalities.
Hurricane is to storm as cirrus is to cloud.
Such a storm is called a hurricane.