A video documents a sudden shift in cloud cover over Saudi Arabia. What's the story?

Satellite images available on the Arab Weather app show a dramatic and clear shift in the path of clouds on Friday, as they shifted from west to east across the Kingdom. This heralds the start of astronomical autumn, the start of a shift in weather patterns, and the approach of the Wasm and rainy season.

Reasons for the change in cloud paths in autumn compared to summer

Meteorologists at Arab Weather reported that the reason for the change in cloud paths is due to the beginning of a shift in atmospheric pressure systems and the decline in the influence of monsoon winds. In summer, clouds usually move from east to west due to monsoon winds, but with the onset of autumn, the monsoon winds weaken and the effectiveness of westerly winds coming from the Mediterranean and Atlantic Oceans increases. Clouds then move from west to east, and with them the chances of autumn rains gradually increase, especially during the Wasm season.

What weather systems will affect the Kingdom during the Al Wasm season?

Seasonal depression recedes:

The seasonal depression begins to gradually recede with the onset of the Wasm season, to be replaced by the Arabian high pressure system, responsible for pushing humid air masses from the Arabian Sea toward Saudi Arabia. This, in conjunction with the Red Sea low pressure system, leads to a gradual drop in temperatures and a break in the intense heat.

The beginning of the Red Sea low activity :

Al-Wasm marks the beginning of the Red Sea depression's actual activity, as it begins to deepen and affect the Levant and northwestern parts of the Kingdom. The depression interacts with humid air masses coming from the Arabian Sea, generating thunderstorms and seasonal rainfall.

The impact of Mediterranean depressions:

The European high pressure system is pushing cold air masses towards the eastern Mediterranean basin, where they interact with the Red Sea low pressure system, leading to instability and heavy rain and thunderstorms.

Siberian high at the end of the season:

The Siberian high begins to directly affect the Kingdom at the end of the Wasm season, leading to a significant drop in temperatures, especially at night, and necessitating the wearing of winter clothing.