What are the differences among ‘Hurricane,’ ‘Super storm,’ and ‘Typhoon’?
Solution 1:
Which term is appropriate for a weather pattern at sea depends on location (generally Atlantic, Pacific, Australian) and on sustained wind speeds, as explained below. Briefly, hurricanes and typhoons have windspeeds of at least 74 mph (ca. 119 km/h). The storms are of the same character under either name; such storms in the Atlantic or the Northeast Pacific are called hurricanes, and if elsewhere in the Pacific are typhoons except where they are severe tropical cyclone or storms. Terminology details are given below.
The following information is quoted from topic A5, “What is a tropical disturbance, a tropical depression, or a tropical storm?” and topic A1, “What is a hurricane, typhoon, or tropical cyclone?” in the NOAA FAQ.
The terms "hurricane" and "typhoon" are regionally specific names for a strong "tropical cyclone". ... Tropical cyclones with maximum sustained surface winds of less than 17 m/s (34 kt, 39 mph) are usually called "tropical depressions"... Once the tropical cyclone reaches winds of at least 17 m/s (34 kt, 39 mph) they are typically called a "tropical storm" or in Australia a Category 1 cyclone and are assigned a name. If winds reach 33 m/s (64 kt, 74 mph), then they are called:
• "hurricane" (the North Atlantic Ocean, the Northeast Pacific Ocean east of the dateline, or the South Pacific Ocean east of 160E)
• "typhoon" (the Northwest Pacific Ocean west of the dateline)
• "severe tropical cyclone" or "Category 3 cyclone" and above (the Southwest Pacific Ocean west of 160°E or Southeast Indian Ocean east of 90°E)
• "very severe cyclonic storm" (the North Indian Ocean)
• "tropical cyclone" (the Southwest Indian Ocean)
The term Superstorm has been attached to Sandy, partly because of the amount of damage it caused and partly because of the several factors that combined to make it so damaging.
As KitFox notes in a comment, a storm need not be rotationally organized, while the terms hurricane, typhoon, and cyclone specifically refer to strongly-rotating weather patterns.
Solution 2:
Here’s my try, according to:
. . .that I can explain to my granddaughter in a single, or few words, without going into lengthy meteorologist’s wordings?
Typhoon and hurricane are the same thing in English. In other languages — take Spanish, for example — they have only one word, which is normally huracán (hurricane) but sometimes ciclón tropical (tropical cyclone) in science writing.
The difference between this and storm (note that big storm keeps being a storm, but bigger) is quite clear, as a hurricane or typhoon is like an arrangement of thunderstorms that produces stronger effects than a simple storm.
So this would be the answer: a hurricane is the same as a typhoon, and both are technically called a tropical cyclone, which is a spiral arrangement of storms.
Note that a big storm could also be referring to a hurricane in some contexts.
Solution 3:
If you look at the dictionary entries for hurricane, you will see that the definitions do not wholly agree.
The most rigorous definition requires (constant) wind speeds of over 74 mph, restricted regions for origin, and restricted directions of travel.
The loosest (literal - there are metaphorical usages) definition (given as the most fundamental sense in Collins) requires only that a 'severe storm' be involved.
Taking the strict, meteorological sense, qualifying storms are further graded into five classes using the Saffir-Simpson Hurricane Wind Scale (Category 5 being the fiercest). Storms below hurricane strength but still severe are known as 'tropical storms'.