Scientific report: A sudden warming in the polar vortex and the Arctic index is trending towards negative. What is the impact of this on weather patterns?

Arab Weather – Weather specialists at the Arab Weather Regional Center are monitoring the latest numerical modeling data regarding the sudden warming of the polar vortex, which, by God's will, has led to the formation of several high-pressure areas over the Arctic Circle. This is impacting the behavior of the polar jet stream and its effect on global weather patterns in the coming period. A detailed scientific report follows.

First: What is the stratospheric polar vortex and how is it built up during autumn?

In detail, the atmosphere consists of several layers, and the stratosphere (10 hPa) is the second layer, located at an altitude of approximately 30 km above sea level. The air in this region is characterized by its dryness and extreme cold, especially above the Arctic Circle. With the onset of autumn, polar regions begin to receive less sunlight due to the tilt of the Earth's axis. This decrease in solar radiation leads to rapid cooling of the stratosphere above the North Pole.

This cooling leads to a significant temperature difference between the poles and lower latitudes. As the stratosphere continues to cool, the westerly winds (under normal conditions) surrounding the polar air masses increase in speed, forming a circular system known as the stratospheric polar vortex. These strong winds trap the cold air inland, separating the polar regions from the temperate zones. With the onset of winter (the current season), the polar vortex becomes more stable and intense, further widening the temperature gap between the poles and other regions.

Second: What is sudden stratospheric warming?

From the above, we can conclude that the stratospheric polar vortex is a vast area of low atmospheric pressure and strong winds that circulates around the North Pole in the stratosphere. The stratospheric polar vortex influences weather patterns in the Northern Hemisphere, including Europe, North America, and Asia. Occasionally, the vortex can become disrupted or disintegrated due to a phenomenon known as "stratospheric abrupt warming," resulting in a flow of cold air from the Arctic toward mid-latitudes, which can cause severe cold waves.

Sudden Stratospheric Warming (SSW) is a weather phenomenon occurring in the stratosphere, where temperatures rise suddenly and dramatically, sometimes by tens of degrees Celsius, within a few days. This phenomenon directly affects the polar vortex, causing it to become disturbed or even collapse, and resulting in significant changes in weather patterns in the regions below it.

Third: A sudden stratospheric warming causes the formation of strong surface high-pressure systems over the Arctic, and the Arctic index (AO) declines sharply towards negative.

Weather experts at the Arab Weather Center said that as a result of the weakening of the westerly polar winds over the Arctic Circle and the descent of polar air from the upper levels of the atmosphere close to the Earth's surface, a temporary stratospheric warming occurs in the Arctic region, causing the formation of strong high-pressure systems over the Arctic Circle during the remainder of January and the beginning of February 2026, and thus the Arctic index is heading towards a sharply negative direction.

Stratospheric warming affects the polar vortex, causing changes in polar air distribution patterns and directly impacting jet stream movement and weather patterns across the Northern Hemisphere. The resulting high-pressure system is expected to disperse polar air masses, leading to larger-than-usual breaks in the polar jet stream and further dispersal of these air masses.

Cold waves and heavy snow are expected in several regions of Europe and the United States in the coming period.

The warming of the polar vortex will result in a series of polar air masses in the coming period, which will rush towards large areas of Europe, in addition to North America and Russia, where the aforementioned countries will be exposed to very cold polar waves and heavy snow with large thicknesses, with the possibility of the occurrence of the bomb hurricane phenomenon, especially in Western Europe and the North Atlantic.

What about the impact of global warming on the Arab region?

Weather analyses indicate that the effects of global warming on weather patterns in the eastern Mediterranean basin and North Africa manifest as clear fluctuations and a constant clash of weather systems. Some countries experience periods of stability and temperature fluctuations, while at other times, air currents with varying characteristics lead to instability or low-pressure systems accompanied by rainfall, God willing. Accordingly, this variation in weather conditions is expected to continue in the coming weeks, alternating between stable and unstable periods. The developments and impacts of this phenomenon on the Arab region will be monitored and tracked in the coming period, God willing.

If we look further towards Northwest Africa, i.e. the Maghreb countries, we find that the warming effects of the polar vortex are represented by the extension of several cold surges that are mainly centered over the western part of the European continent and extend to the Maghreb countries and the western Mediterranean, causing the formation of deep atmospheric depressions that lead to heavy rainfall and possibly snowfall.

And God knows best.