Croatia Faces Warm Autumn and Mild Winter
The European Centre for Medium-Range Weather Forecasts predicts above-average temperatures through early 2027, while precipitation remains a major unknown.
The European Centre for Medium-Range Weather Forecasts predicts above-average temperatures through early 2027, while precipitation remains a major unknown.
The latest seasonal forecast from the European Centre for Medium-Range Weather Forecasts (ECMWF), released on August 6, 2026, delivers a fairly clear signal for Croatia. There is a high probability that the end of summer, the entire autumn, and the beginning of winter will be warmer than the usual climate average. This forecast relies on a set of 51 numerical simulations and is particularly intriguing because it comes at a time when several major climate phenomena are unfolding simultaneously and could influence one another.
Meteorologists are closely monitoring two major ocean anomalies that could significantly impact weather conditions during the winter of 2026/2027. These are a strong El Niño in the Pacific Ocean, which could reach the level of a so-called Super El Niño, and a positive phase of the Indian Ocean Dipole (IOD) in the Indian Ocean. As reported by Severe Weather, the combination of these two phenomena can act as a powerful driver of atmospheric changes, altering the position of jet streams and storm tracks across the Northern Hemisphere.
Current analyses indicate that the positive IOD is still developing, but it could strengthen further during the autumn. Meanwhile, sea surface temperatures in some areas of the Pacific Ocean are already several degrees above average, and the heat energy stored below the surface further supports the development of El Niño. If the forecasts materialize, this could be one of the strongest El Niño events in modern recorded history.
In addition to El Niño and the IOD, the weather in Europe will also be influenced by the still very warm North Atlantic and the record-warm Mediterranean and Adriatic seas. After the summer, the sea entered autumn with a vast amount of stored heat, making it an important source of heat and moisture for cyclone development. For this reason, it is expected that this autumn will see alternating longer periods of stable weather with episodes of extremely heavy rainfall and pronounced meteorological extremes.
The ECMWF seasonal model for August shows a positive temperature anomaly of approximately one degree Celsius compared to the climatological average. Although the predicted amount of precipitation is within normal limits, this does not imply that rain will be evenly distributed throughout the season. Due to the moist air, there is potential for the formation of strong storms, so a large portion of the monthly rainfall could fall in a few intense thunderstorm events, characterized by heavy downpours.
The model-computed air temperatures for the first months of autumn also remain above the multi-year average. September could behave more like an extension of summer rather than an introduction to meteorological autumn, and sea temperatures will likely remain higher than usual. As for precipitation, the situation is quite different, from October onward, differences in computed rainfall amounts among various models become significant. The key question is not whether there will be precipitation, but when it will occur and which routes the cyclones will take.
According to long-term forecasts, during the winter of 2026/2027, Europe could be under the influence of a stronger westerly wind coming from the Atlantic. This type of weather pattern typically results in mild and rainy winters, especially in western and central parts of Europe. The seasonal model indicates that the beginning of the climatological winter could be warmer than average, but this does not rule out the possibility of cold air intrusions.
Conversely, during El Niño, the atmosphere often becomes more unstable and dynamic. Instead of long periods of stable cold, a more frequent alternation of warm southwesterly flows and short but very strong bursts of polar air from the north and northeast is more likely. For Croatia, this means that snow will still be possible, especially in mountainous areas and the interior during cold intrusions, but between these periods, warmer weather will likely dominate. A final forecast is not yet possible, and the actual strength of El Niño and the development of the IOD during autumn will be crucial for the final weather pattern.
