Here’s an entertaining piece from Roger Harrabin of the BBC sci/environment team:
Met Office model ‘better at predicting extreme winters’
UK weather forecasters can predict cold winter weather a season ahead with more confidence, according to analysis of a new computer model.
Writing in Environmental Research Letters, scientists say the model is better at simulating phenomena known as sudden stratospheric warmings (SSWs).
These happen when the usual westerly winds at 10-50km altitude break down, causing cold weather on the surface.
Developers at the Met Office say it is an incremental advance for forecasts.
Seasonal forecasting is still in its relative infancy, but the report’s authors from the Met Office say that improving their ability to represent SSWs [Sudden Stratospheric Warmings] is a help.
The high-top model was devised in time for the winter of 2010-2011.
Using its data, the Met Office forecast in autumn 2010 that there was a 40% chance of a cold start to the winter, with a 30% chance of a mild start, and a 30% chance of an average start.
However, Judah Cohen, of the US-based Atmospheric and Environmental Research (AER) said:
“The Met Office have shown great creativity in exploring gaps in our knowledge and deficiencies in the models. But frankly, the bar for seasonal forecasting is set pretty low so any advance is very welcome.”
So low in fact, that the MET Office has declined to give seasonal forecasts for winter over the last couple of years, after the spanking they got from the media about the failed ‘mild winter’ forecast in 2009.
Perhaps part of the issue is that they don’t include the QBO in models of the atmosphere, as Dr Tim Ball recently pointed out.
Read the whole story at the BBC website.