First speculations: How is our winter looking this year?
12 November 2023
How is our winter looking this year?
What will this winter be like, and will we see snow at Christmas? Many people want to know, but such predictions are dubious.
Forecasts for the coming winter are anything but certain. They are often based on long-term forecasts from weather models.
These forecasts are changeable though, and can even change from week to week. You should take them with a pinch of salt, but with that in mind, we can assess the overall trends. Is it looking warmer or colder than average? Wetter or drier?
Warmer than average
The GFS indicates a warmer than average winter.
This year, both the American Weather Service's Climate Forecast System (CFS) and its European counterpart (ECMWF), are predicting an above-average winter in terms of temperatures. Not a bold statement in times of climate change.
In addition, not only is the Pacific Ocean currently warmer than average due to El Niño, but also the nearby Atlantic Ocean. The arrival of El Niño has on occasions been linked to enhancing the risk of colder winters across the UK and Ireland, but this is not guaranteed.
The volcanic eruption on Tonga in the South Pacific last year is also related. It hurled enormous quantities of water vapor into the stratosphere, where it is likely to remain for several years and can affect the long-term conditions of the global climate.
This water vapor has spread further into the polar regions of the earth, where its warming effect may even influence the polar vortex. Whether this will affect the weather through winter is still completely open due to the uniqueness of the event.
Conversely, if large amounts of sulphur are released during an eruption, the opposite effect can take place. The sulphur in the stratosphere can reduce the incoming solar radiation, and cause a reduction in global temperatures.
Water vapour is a very powerful greenhouse gas. Any significant increase could lead to warming of the lower layers of the atmosphere.
Even if there are many indications of an above-average warm winter, there are still major uncertainties. Even if it is currently warmer than average around us, cold polar air can quickly penetrate southwards depending on the weather conditions.
In corresponding weather conditions with prevailing easterly winds here in the UK and Ireland, a cold winter is by no means off the table.
Additionally, even if the winter is warmer than average statistically, as a whole, there can still be days with snow and ice, though it would be impossible to pin down exactly when at this stage.