Severe Weather in New Zealand

Tornadoes, Hurricanes, and the Isssshhh

Maaaaan, damnses weather, you scary!

Yous guyses know what a zornado es? And no... nots zat sharknados craps. Jeebus.. I mayses of watched it but that shiz could never happens! Everyone knows sharks are afraid of heights so they would never get caught up in a tornado let alone bite the shiz outta peoples while spinning around uber fast. 

 ..... however...................

...........



 ....................  Baboonami is real! 

Anywho,  A tornado is a rapidly rotating narrow region of low pressure.

Tornadoes first start as body of air just rolling around all stupid on the ground due vertical wind shear which is a gradient/ difference in winds speed and direction.

With a vertical shear the difference is between air aloft and surface winds.

 This rotating mass then is lifted off the ground by an updraft of a thunderstorm and once it is nearly vertical it is considered a mesocyclone.

This vertical cylinder of air narrows into a funnel cloud and once it touches the surface it is considered a tornado.

Funny, spellcheck thinks i meant to spell lonesomeness instead of mesocyclone...

This is pretty cool though.

So, in the US tornadoes move from southwest to south east. As with most weather movements and stuffs this movement is due to our prevailing westerly winds and also a jet stream.


Tornadoes also happen in New Zealand, hey what do ya know... And they are associated with a band of thunder storms (squall lines) that are balls deep in a strong unstable pre-frontal northwesterly flow. There's about 7 moderate to strong tornadoes in New Zealand a year.





Now for the US, according to the National Oceanic and Atmospheric Administration (NOAA)There an average of 1000+ tornadoes a year!

Up thurr is a map detailing the hotpots of tornado occurrences.

Areas shaded in orange are the most prone to have tornadoes and there that little big orangy thing to the southeast is New Zealand. We be feeling hot hot hot!

Now look at this ish. This here picture shows that tornadoes have increased over the years!

Oh no its climate change again! Oh wait, maybe not. Actually this increase may mostly be due to an increased ability to observe tornadoes with uber hitech scifi technology we have these days.

Hurricanes

The three main requirements for hurricane formation is a warm ocean temperature of greater than 80 degrees F (27C) because ya need evap.

A deepwarm ocean layer of ~200m in depth cuz when wind pulls up water you still gots that warm ish.

And that ole crazy Coriolis is needed to create that spin but only between greater than 5 North and 5 South cuz Coriolis is a weak mofo at the equator it's his kryptotonanight.

New Zealand does satisfy the requirement for Coriolis effect but does not satisfy the other two as the country lies further south so the ocean temps are not as warm and deep like countries between the equator and 20N, S.

Hurricanes typically form in three main regions where they also referred to as different names. Saaay whhaaaa?





 In the Atlantic and East Pacific they are called hurricanes; in the Indian Ocean near Australia, cyclones; off the coast of China and Indonesia, typhoons.

Hurricane, Cyclone, Typhoon, Whatever map

http://spaceplace.nasa.gov/hurricanes/en/cyclone_map_large.en.gif

As you can see in the diaphragm, hurricanes in 'Murica typically move north east due to the Toyota Corrolla effect pulling it north and the westerlies blowing it east. 


The average number of hurricanes that hit New Zealand (stop the violence :/ ) is 0 as Hurricanes do not happen in New Zealand.

They can occasionally get hit by the remnants of a hurricane during the months April-December where the ocean temperatures are higher around the islands. Mostly though, hurricanes just peter out before they come close to land.

Compare this to number to the US, which has an average around 1.75 hurricanes per year according to the Hurricane Research Division of NOAA.


Also, checkout this insane footage of a HURRICANE doing damage in New Zealand!!!