What does the weather have in store for November 2024? A forecaster on the latest model calculations

The golden Polish autumn is coming to an end. Dan Pearson, an English gardener, noticed that now the colors disappear and the branches stripped of leaves show the skeletons of plants. We are surrounded by rot and decay, but it is not death that should worry us, just the peak of the annual cycle. The growing season is ending and the weather is usually gray and gray.

In Poland, November, associated with multi-day fog and piercing cold, is changing as the weather warms. Although every year the so-called “rotten” high pressures settle over Europe at this time, which “suffocate” moisture and smoke at the ground due to their typical air subsidence processes, but November is more and more often sunny and moderately warm, with the average daily temperature remaining above 5 degrees Celsius, i.e. above the thermal threshold between autumn and pre-winter. What will it be like this year?

High pressures have spread heavily in Western and Central Europe. The precipitation forecast for Europe for November, calculated by models of the US National Oceanic and Atmospheric Administration (NOAA) and the European Center for Medium-Range Weather Forecasts (ECMWF), indicates a clear drier season due to high pressure anomalies. This means a continuation of weather shaped predominantly by high pressure systems. According to American forecasters, only the far north and the east of the continent will record more rainfall than usual. The European model, however, assumes that the amounts will oscillate around long-term norms. It should be noted that rains in November in Poland are not impressive, they range from 30-50 liters per square meter. Only on the coast they are more abundant, up to 60 l/sq m, and high in the mountains they exceed 100 l/sq m.

The highs over Europe only briefly, every now and then, give way to Atlantic storm lows. At the beginning of November, this system, over western Europe, gives some scope to low pressures over the North Atlantic and Arctic Ocean. The wind is therefore increasing in Poland, and dangerous storms are possible over the northern and north-eastern regions. This is a temporary situation, because around November 4 the high pressure will expand enough to calm the wind. A large high-pressure embankment is to develop from the British Isles, through the Balkans, to northern Africa and constitute a barrier to storm lowlands. It is clearly visible in the calculations of the American GFS model as late as November 10. The forecast of pressure deviation from the norm shows a very stable situation in Western and Central Europe. This arrangement in the atmosphere does not disappear quickly. In summer it would mean “like a wire” weather – sunny and warm, but in November it means cloudy and foggy weather with clear and bright spells.

High pressures are expected to keep northern storms in check for at least two to three weeks. Trapped in high latitudes, they are supposed to carry rain and snow far from Poland. Cloudy, windy lows emerging in the Labrador region are expected to circle the high and follow an arc along the Greenland-Swalbard route, eventually penetrating deep into Russia. And Poland, located between east and west, will only occasionally enter the zone of lower pressure, stronger winds and mixed rainfall. If you collect a total of about 20 liters of them throughout the month in the center of the country, it will be good, and that's how much it rains on one stormy summer afternoon.

Such a stable high over western and central Europe, a ridge stretching north-south, and lows diving over eastern Europe pose a certain threat. They build a path for cold air masses to freely penetrate from the north. Usually, the biggest impact is directed towards eastern Europe, where new portions of cold air arrive between waves of snowstorms. But Poland then reaches the edge of the gulfs of cold.

Therefore, by mid-November the temperature may increase in the afternoons to 5-10 degrees Celsius, especially in the west, but we cannot count on more. It may be worse in the east. Thermally, this year's November will be normal and slightly above normal according to American and European forecasts. NOAA estimates that slightly more warmer air masses will penetrate the western and northern regions of the country, while ECMWF estimates that the eastern and southern regions will be slightly warmer. However, according to both centers, the deviation for the entire month would amount to about 1 degree C. This is not much and means that November may as well be a completely normal thermal month. This is especially true since the forecasts of seasonal models tend to show generally milder weather in autumn and winter, and, above all, higher temperatures.

If we take a closer look at the forecasts of the European model, we will see that cold waves will appear in November, and the temperature will sometimes drop below 0 degrees Celsius. A strong high pressure in the first half of the month is expected to favor the flow of cold air masses from the north. The first cold weather will come on the weekend of November 2-3. On Sunday morning, the temperature in many regions will drop to -3 degrees Celsius.

Another wave of cold from the north and east should be expected before November 10. The temperature is expected to drop significantly below normal, which means there will be cold on the ground, and possibly accompanied by fog and low clouds. Unfortunately, the chances of this cold remaining longer, at least until the middle of the month, are high.

After November 10, high pressure levels should change their location and move to the east of Europe. According to the calculations of the American GFS model, the high pressure would strengthen over Russia and pull raw air masses from the east, from the depths of the continent, forming tongues of cold. They would cover eastern and south-eastern Poland. The temperature would not only drop below 0 degrees Celsius at night to -8/-5 degrees Celsius, but it could still be negative during the day. In the western regions of the country, thermal conditions would be milder, but typical of November, when the temperature does not exceed 5 degrees Celsius in the afternoon.

In the second half of November, the cold should ease up a bit. According to ECMWF, more mild air masses would enter Poland from the west and southwest. As the high pressure moves eastward, the Atlantic low-pressure vortices would begin to penetrate the European continent more strongly and carry billowing clouds, rain and strong autumn winds that would blow away the fog. And they would not allow the temperature to drop below 0 degrees Celsius. Will Poland eventually fall under their influence? The ECMWF model assumes that after November 18 and by the end of the month, the average temperature in the west and north of our country should be slightly higher than usual. In Pomerania, Warmia and Masuria the positive deviation could be as much as 2 degrees Celsius.

The last fanfares of golden autumn sound around us. Late autumn is coming, bordering on winter. However, the date of the beginning of winter changes from decade to decade. In the second half of the 20th century, the type of weather typical of early winter began to appear in October, now it can occur even at the end of November or the beginning of December. And this year, seasonal model calculations paint a picture of a rather mild end to autumn. But will the high pressures that feature strongly in the forecasts really be benevolent? It seems that in the second decade of the month they will remind us that we are entering a time of year with a rather ugly and sad face.