These clouds show waves rolling along and breaking in the sky, similar to the way that waves behave on the sea.

Wet and windy conditions battered parts of New Zealand around Friday 13 August

It looked like a row of teeth

Written by Ross Marsden, Meteorologist

On the afternoon of Monday 19 July 2010, a neat set of four persistent contrails moved across the Cook Strait area.  NASA's  MODIS Rapid Response System captured the contrails in the image stream from the Aqua space craft which was over Wellington at about 2:20 pm. You can see the image on the MODIS web site here:  http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=NewZealand.2010200.aqua.1km  Here’s part of the MODIS image.

Clouds come in many different types and are characterised and named according to both their shape and height in the atmosphere.  While a single snapshot in time at a given location may only contain one type of cloud, there are many days when multiple cloud types can be observed in the sky at once. The satellite images below is a nice example of different cloud types sitting at different levels above Waikato. Here's what the satellite image looked like Saturday afternoon 3 July 2010, for southwestern parts of Waikato near Kawhia Harbour:

Written by Chris Webster, Meteorologist

We had an enquiry from an astute member of the public asking about the comings and goings of rain.   They had noticed that in southerly weather the rain has a tendency to "come in bands (e.g., 20 minutes rain, 20 mins dry, 20 mins rain etc.) rather than as a more constant rain that comes with northerlies". They were wondering why this was. This is a good question and I will try to answer it here.  

All the best for researching your school assignment about weather and climate during the school holidays :)

There was a lot of rain in many parts of New Zealand over the last two weeks of May 2010. One of the few places to escape this was the sunny West Coast of South Island - the days are clear and stunning there when the flow is southeasterly. If you had been following the surface weather maps during May you would have noticed a lot of low pressure over the Tasman Sea and northern NZ, and periods of relatively high pressure farther south.

MetService issues severe weather warnings to New Zealanders whenever widespread heavy rain, heavy snow or damaging winds are expected. There are formal criteria that events have to meet or exceed for the forecast to be called a success; the wind criteria are in a previous post, while the rain and snow criteria relate to the total falls required within set periods.