KEY POINTS:
Well as much as I want to talk about our first set of real spring weather moving in it really does pale in comparison to Hurricane Gustav - a huge hurricane that could cause catastrophic damage to America's southern states.
I've been working through the numbers and have some pretty amazing stats to share with you on this major hurricane - converted to metric units to make it easier to understand.
A storm of this size is rare - and its path is a very predictable one. At the end of last week I could see that Gustav was going to be worse than the other 6 named storms so far in the Atlantic Hurricane season.
In fact, we've even dedicated a section of the Weather Watch Centre to Gustav with incredible satellite images from NASA updated hourly and a plot of Gustav's track, also updated hourly, from weather.com.
There's so much info online about this storm we've decided to keep the news brief and easy to follow. I've been surprised at how many people have told me they want to know more about this storm - and one of the comments posted on our site yesterday was from a lady in Louisiana who had been told to evacuate...her town is directly in Gustav's path.
It must be incredibly scary for her, to pack up your treasured belongings and leave your home. I chatted to her briefly and she said her biggest worry would be returning later in the week - anything could happen. Her house may not be there when she gets back.
We don't see storms like this in New Zealand. The only storm I can think of in our entire recorded history would've been the "super storm" that sank the Wahine. Winds in that reached 275km/h at one point in Wellington. That's very similar to this storm, however unlike Wellington, these winds are reaching this speed in the open water - and not because of the geography around it.
So the stats on Gustav:
Winds: Winds averarging 220km/h - and they're likely to increase further today. These are winds SUSTAINED. Not gusts. I have been in winds gusting to 180km/h and it was hard to breathe - the air just flew by my mouth. 220km/h sustained is incredible. You know the strength of the wind on your hand out the car window at 100km/h - well this is over twice that force. There are gusts much higher - up to 280km/h., probably up to 300km/h today. The V8's at Bathurst make it to that speed at their very fastest.
Rain: We often hear rain warnings for the South Island calling for 200 or 300 mm - Gustav had warnings for 500mm in Cuba yesterday. Rainfall figures will be similar for America when Gustav arrives and slows down. 49% of New Orleans is below sea level with some areas three metres below sea level so this will be of real concern, esecially when combined with the storm surge.
Storm Surge: A storm surge is a combination of the sea rising around the centre of the storm (to put it simply, high air pressure pushes the sea down like a big hand - the eye of a hurricane has very low air pressure - the lower the pressure over the water the more it lifts up. It's like a gigantic vaccuum) and also strong winds pushing the waves up on top of each other. Storms surges can be many metres high and when high tide arrives each wave that crashes moves further and further inland - sometimes many kilometres inland. The waves out in the midde of the Gulf of Mexico are estimated to be around 14 metres high at the moment - with rogue waves possibly twice that. That's 1 and half times the height of a 747. That gives you an understnding as to why so many oil rigs were damaged by Hurricane Katrina 3 years ago. This storm is going to move through the highest concentration of oil rigs in America so hopefully the lessons learnt from Katrina will protect them better this time.
The storm will start to have an impact on the US by Monday night our time - and should make landfall during Tuesday NZT. We'll provide links to free rain radars at the Weather Watch Centre as the storm rolls in - it's amazing when you can actually see the "eye" rotating, plus all the latest satellite images, wind speeds and tracking.
Philip Duncan
Pictured above: US National Hurricane Centre director Bill Read studies one of numerous tropical cyclone forecast models tracking Hurricane Gustav. (AP Photo/Andy Newman)
For the latest weather news keep up to date with The Radio Network's new Weather Watch Centre or the NZ Herald weather section.
