A cold shiver ran down my spine earlier this week when I read, "Britain faces an early big freeze".
It's a brave forecaster who sticks their neck out and gives such detail on a span of three months ahead. Long range forecaster James Madden from Exacta Weather though has done just that. He expects "December, January and February to experience below average temperatures, with the heaviest snowfalls occurring within the time frame of November to January across many parts of the UK". So kids, dust off the sledges and dads, best to order a tonne of grit for the drive now just to be on the safe side...
The forecast is based on a number of factors that include a spell of quiet solar activity (that allows the atmosphere to cool), renewed volcanic eruptions in Iceland (Eyjafjallajokull and Grimsvotn) and indications of a neutral ENSO or La Nina (large scale wind and ocean currents over the southern Pacific that effect weather patterns across the globe). As a forecaster its fascinating stuff - on one level how the global weather is so interconnected, and on another, how far we have come in understanding natural phenomena and how it relates to future weather events.
The dynamics of the atmosphere relies on a fine balance of numerous factors and is highly sensitive to slight perturbations. This is one reason why seasonal trends are so difficult to get right. The best computer models can give a huge variation of predictions, and throughout the season the detail is continually revised.
Another is that seasonal forecasts can be open to a lot of interpretation.
When in the spring of 2009 the UK's Meteorological Office forecast 'higher than average temperatures' for the months of June, July and August, it was eagerly anticipated as the forthcoming 'barbeque summer' - oh, how it rained (although at least it was warm rain).
I suspect that this is one of the reasons why the Met Office has now stopped releasing their seasonal forecasts to the press and public.
I am not saying that the forecast published earlier this week is correct or not but broad brush long range forecasts will normally result in some detail being right somewhere in the country.
So what can we expect for the near future? Well dominant south-westerly winds will keep the rest of September mild, perhaps even warm in the southeast, with the risk of more rain, mainly in the west. Towards the end of the month there is a hint of some drier, brighter weather for everyone.
Come October there is good agreement amongst many forecasting units that many nights will be cold and frosty, but it's likely to be drier than average - with some lovely sunshine by day.
As for the coming winter - the 'big freeze' forecast has been the only one issued so far, so let's just say for now, forewarned is forearmed, and in a country where our airports grind to a halt when there's a dusting of snow, being prepared is not such a bad thing.Suggest a correction