Europe faces a higher-than-average chance of a cold snap before the end of the year, but winter overall is likely to be warmer than average, the continent’s long-range weather forecaster said on Thursday.

Temperatures this winter will be crucial for homeowners worried about record costs to heat their homes and for European politicians trying to avoid energy rationing due to cuts in Russia’s gas supply.

“We see winter as warmer than usual,” said Carlo Buontempo, director of the Copernicus Climate Change Service, which produces seasonal forecasts for the European Center for Medium-Range Weather Forecasts (ECMWF).

“Nevertheless, there is still a significant chance of a deadlock situation that could lead to cold temperatures and weak winds over Europe,” he told AFP when the service issued a monthly update of its forecasts.

A so-called block or lock pattern in winter can bring stable, often wind-free weather with sub-zero temperatures.

“This looked more likely in November, but it now looks like a distinct possibility of a cold outbreak in December,” Buontempo said.

The ECMWF creates weather models using data from a number of national weather services across Europe.

Its forecasts are based on indicators such as ocean and atmospheric temperatures and stratospheric wind speeds, but lack the accuracy of short-range reports.

The models provide the “best possible information to provide a clue to guide our decisions,” Buontempo said.

The European winter was expected to be warmer than usual due to the global weather phenomenon “La Nina” associated with the cooling of surface temperatures in the central and eastern equatorial Pacific.

“We know that in a La Nina year, the latter part of the European winter tends to favor westerly winds, so warm and wet,” Buontempo said.

The agency will update its forecast for the winter season next month when it will have greater confidence because “all riders will be more active for the winter,” he said.