Hurricane FAQ’s: Part I

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All Will Soon Become Clear . . .

What is the difference between a hurricane, a typhoon and a tropical cyclone?

Well, for starters, hurricanes and typhoon are the same thing, it just depends on which part of the world you come from, and they’re all tropical cyclones . . . of different strengths. If a tropical cyclone has sustained surface wind speeds of less than 39 miles per hour it’s called a tropical depression, if the wind speed picks up to more than that it’s called a tropical storm (or a Category 1 cyclone in Australia), and if it reaches sustained surface wind speeds of more than 74 miles per hour it becomes a hurricane in the North Atlantic, east of the dateline in the Northeast Pacific and South Pacific (well, east of 160E anyway). Complicated isn’t it? Anyway, if all of this happens west of the dateline in the Northwest Pacific it’s called a typhoon, and if it’s going on west of 160E in the Southwest Pacific or east of 90E in the Southeast Indian Ocean it’s either a “severe tropical cyclone” or a “Category 3 cyclone”, in the North Indian Ocean they have “very severe cyclonic storms” and they have simple “tropical cyclones” in the Southwest Indian Ocean. So you see, it just depends on where you are!

What is a “major hurricane”?

The term “major hurricane” is used by the National Hurricane Center to describe any hurricanes which reach a minimum of 111 miles per hour sustained surface wind speed – they would be either a Category 3, Category 4 or Category 5 using the Saffir-Simpson Scale.  Don’t be fooled though, even Category 1 and Category 2 hurricanes which aren’t classified as “major” can still cause major amounts of damage.

What is the difference between a “storm surge” and “storm tide”.

“Storm Surge” is the amount of water which is generated by the storm, more than the astronomical tide which is generally predicted. “Storm tide” is the amount of rise in the water level because of the storm surge and the normal astronomical tide put together. Basically, it can result in a giant wall of water rushing onto the land the causing flooding even many miles inland. Bad news . . .

What makes a tropical cyclone?

“Tropical cyclones“, simply speaking are like baking a cake. You need all of the right ingredients to bake a chocolate cake, without the right ingredients the cake might not be very tasty, but even with the right ingredients, if you don’t follow the correct procedure it could still be horrible (yes, I know . . . ) Tropical cyclones need a mixture of #1 – warm ocean waters, at least 150 feet deep and at least 80 degrees F,  #2 – a cooling atmosphere, unstable to convection of the moisture,  #3 – pretty moist layers towards the mid-troposphere (3 miles), #4 – at least 300 miles from the equator, #5 – a disturbance close to the surface which has sufficient convergence and vorticity, #6 – low amounts of vertical wind shear (23 miles per hour) between the upper troposphere and the surface. Basically, mix all ingredients then stand back and watch the results . . . stand well back.

What does the word “hurricane” actually mean?

The word “hurricane” comes from the Carib god “Hurican”, which was originally derived from “Hurakan”, a creator Mayan god. Anyway, according to Mayan beliefs “Hurakan” blew across the Chaotic water to bring forth dry land, and a little later whipped up a great storm and flood to destroy the men of the wood. Sounds familiar!

Where do hurricanes names come from?

There are 6 lists of hurricane names which rotate yearly. The first hurricane of a year has a name beginning with the letter “A”, the second “B” and so on . . . Both male and female names are used, and every 6 years the same list will come around again. There are 21 names on each list, if, (for example in 2005) there are more than 21 hurricanes in one year then the following hurricanes are given the letters of the Greek alphabet . . . Alpha, Beta etc.  If there is a particularly bad hurricane (for example Katrina in 2005) then the name will be replaced on the list with something else . . . otherwise it could get confusing and also be very distressful for the thousands of people who suffered during a particular hurricane.

Has anybody ever tried to stop a hurricane?

Only Superman . . . just kidding. The US Government has actually been involved with experiments to modify hurricanes . . . ie reduce their strength, with a project known as Stormfury. The NOAA tried dropping silver iodide into hurricanes in an attempt to weaken them. Unfortunately (as you might have noticed) there attempts were pretty unsuccessful, so these days the NOAA concentrates more on learning how to understand hurricanes and improve the accuracy of the forecasts.

Can’t we harness the power of a hurricane?

If you can figure out a way to do that then you’ll be able to join the Bill Gates’ of this world . . . and that’s for sure. Not only would you be a millionaire you’d also be the savior of thousands of people, properties, animals, trees etc. etc. Wow, you’d be a superhero. Perhaps it’s worth a little more serious consideration!

You heard the man, “the best thing we can do is to get out of the way” . . . hear hear!

 

I’ve heard that when there’s a hurricane you should open all of the windows and doors on the lee side of the house, and close them on the storm side. Is this true?

No, keep everything tightly closed with hurricane shutters installed over the windows (or a little DIY 5/8″ plywood sheets) if at all possible. Any windows or doors which are left open can cause BIG trouble.

Does it help to tape windows in a hurricane?

No, it’s a complete waste of time, your efforts would be better placed putting up some 5/8″ plywood boards, or even 1/2″ if that’s all you have, it’s better than nothing. Apart from tape having no benefit to the glass during a hurricane whatsoever, just think about how long it will take you to peel it off again when the hurricane season has passed . . . I’m sure you can think of better things to do with your Sunday afternoon!

How are hurricanes ranked?

With the Saffir-Simpson hurricane intensity scale.

Why do hurricanes usually have the strongest winds on the right side?

First things first . . . the right side of a hurricane is all to do with the motion . . . a hurricane which is moving north has it’s right side on the east, a hurricane which is moving west has it’s right side to the north etc.  The swirling motion of the hurricane causes the strength of the winds, think about it like being on a fairground ride, one of those which spins you round and round, you’ll find that, depending on which way you spin, the person on one side of the ride will get much dizzier than the person on the other! Something to do with physics . . . should have paid more attention in class really. Anyway, say that a stationary hurricane has winds of 90 miles per hour, if it begins to move the winds will be around 100 miles per hour on the right side and 80 miles per hour on the left.  Remember that hurricanes in the southern hemisphere swirl the other way around so everything would be reversed.  

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