Sometimes in MetService forecasts, you will see a forecast for “fresh northerlies”. But what exactly does the word ‘fresh’ mean? For many people, the word ‘fresh’ carries connotations of cool or clean air (eg the phrase ‘fresh air’). However, the word ‘fresh’ also has a more technical definition, that comes from the Beaufort Scale.
Mean Wind Speeds vs. Gust Speeds
By meteorologist Emma Blades
As a cold front swept up the North Island on Sunday 24 April 2016 it was like a blanket had lifted leaving blue skies behind. In the classic cold-front scenario, showers usually follow the main rain band. But because the flow was west to southwest behind the front, the South Island was sheltering the North Island from the showers, resulting in clear skies behing the front in this case.
Day-to-day weather features such as fronts and troughs, highs and lows constantly wash against New Zealand in the global atmospheric circulation. Sometimes the weather in New Zealand is highly changeable, changing from heavy rain to blue skies with an almost daily frequency. Other times the weather can seem to be stuck one way or another for days. In this blog we discuss the reason for this: Planetary waves, also known as Rossby waves. We will also look at the tools forecasters have to analyse them, and the implications for New Zealand.
March 23rd is World Meteorological Day, a day when National Weather Services around the world commemorate the establishment of the World Meteorological Organisation (WMO), which occurred on this day in 1950. WMO is a global agency which co-ordinates meteorological and hydrological activities. Having international collaboration is very important, as weather will not stop and wait at the border between two countries!
Celebrating the increased participation of women in meteorology
March 2016
International Women’s Day is held every year in March and to mark this occasion we want to give a big shout out to all the great women working here at MetService. Since 2001 we have trained 34 women and 30 men to be World Meteorology Organisation (WMO) qualified meteorologists. Twenty years ago the statistics were very different.
From “The New Zealand Weather Book” by MetService Expert Meteorologist Erick Brenstrum
Blog published by Lisa Murray Communications Meteorologist
Satellite image of Tropical Cyclone Bola, before moving south towards New Zealand and evolving into a mid-latitude Low. Image from NOAA-9
It may seem obvious. Weather is what we experience locally day-to-day and week-to-week, while climate is a background signal sitting ‘behind’ the weather, observed at the seasonal, annual or even decadal time scale. But the interplay between what is dominate in the short-term and what prevails in the longer run, is not so straight forward. For example, 2015 was a very dry year for regions in the north and east of both islands of New Zealand. But there were rain events in these areas, and some of them were very heavy.
The annual average fogs for Wellington Airport is 6 fogs per year, much rarer than at Christchurch (50 days per year) or Dunedin Airport (64 days per year) or Hamilton (92 days per year), yet it is very disruptive when it does roll in off the sea and can last for hours at a time. Interestingly, Wellington gets more fog days in summer while fogs occur in winter for many other airports. Wellington airport is a hub for domestic commercial air traffic, therefore even short closures have major flow on effects for passengers and other airports around the country.
This guest blog was produced by Cancer Society NZ.
Sunburn now could lead to melanoma skin cancer later in life – no matter what your age or skin type. This is a lesson learnt too late and it can be started early by educating children to become Sunsmart savvy.
Here is an explainer on the difference between the rain radar imagery and rain forecast imagery available on metservice.com and how to use them.
Rain radar