You may not believe it, but it's true. Not long ago, Dubai, United Arab Emirates, a desert tycoon city famous for its high-rise buildings, luxury cars and watches, and artificial islands, was hit by an unprecedented torrential rain, which dropped two years of local precipitation in one day, turning this usually dry and rainless place into an ocean.
1. Heavy rainstorms hit the desert tyrant city
On April 16, local time, affected by the rare Arabian Peninsula low pressure system, Dubai, United Arab Emirates was hit by an unprecedented rainstorm, and Dubai Airport received 165mm of precipitation within 24 hours, equivalent to two years of local precipitation. In addition, super heavy rainfall also hit the eastern part of the United Arab Emirates, western Oman and southeastern Iran, with 24-hour precipitation generally reaching 70~140 mm.
For Dubai, where such intense rainstorms have led to a series of chaos in the city, Dubai International Airport said the airport was severely disrupted due to bad weather and was working to resume normal operations as soon as possible. Affected by the storm, flights to Dubai International Airport were temporarily diverted on the evening of the 16th, and operations were suspended for 25 minutes earlier in the day.
The heavy rains not only hit the UAE, but also other countries in the Arabian Peninsula, such as Oman, Yemen, Saudi Arabia, and the southeastern region of Iran. The 24-hour precipitation in these areas has generally reached 70~140 mm, and even more than 300 mm in Oman. Many parts of these countries are usually relatively arid and have little rainfall, and such precipitation is very rare for them, and it can even be said that it is not seen in a century.
Second, Dubai has dropped water for two years in one day!
The torrential rain has had a serious impact on local life and traffic. Dubai's roads are flooded, vehicles are trapped, flights are canceled, schools are closed, and shopping malls are flooded. Floods and landslides have also occurred in some parts of Oman, killing at least two people and injuring dozens. Some parts of Iran have also suffered from flooding, which has killed at least 12 people and displaced thousands. This news has sparked heated discussions among many netizens, some people exclaim that "the earth is messed up", some people sigh that "the desert has become an oasis", some people ridicule "Dubai is going to build a water park", and some people are worried that "will this affect the weather on the mainland?"
So, how did this rare rainstorm come about? Actually, it has to do with the violent oscillation of the westerly wind belt upstream. The westerly wind belt refers to a series of air currents blowing from west to east in the mid-latitudes, which are important regulators of global climate and one of the main factors affecting continental weather. The intensity and location of the westerly wind belt will change with the seasons and climate change, and sometimes there will be abnormal oscillations, that is, the high and low pressure systems of the westerly wind belt will alternate rapidly, resulting in drastic changes in the direction and speed of the air flow.
This time, it was due to the abnormal oscillation of the westerly wind belt that caused an unusually deep trough to sweep over the Middle East. A deep trough is a curved airflow in a westerly belt where the air pressure is lower than the surrounding airflow, which is usually accompanied by the southward movement of cold air and the northward movement of warm and moist airflow, resulting in the collision of cold and warm air masses, triggering strong convection and precipitation. This time the deep trough was so strong that it even cut off at the southern end to form a cold vortex system, and its southern side attracted a large amount of water vapor from the Arabian Sea, forming a strong warm and humid air flow, while its northern side brought cold air from the Iranian plateau, forming a strong cold and dry air flow. The two currents met over the Arabian Peninsula, creating a violent convective movement that formed a wide area of clouds and precipitation.
3. Messed up?
Such a deep trough is very rare in the Middle East, because the pressure field here is relatively stable, the influence of the westerly wind belt is not great, the temperature is high, the water vapor is low, and precipitation is scarce. However, due to global warming, the intensity and location of the westerly wind belt is likely to change more, leading to the emergence of more anomalous deep troughs, which will bring more extreme rainfall events to these arid regions.
So, will this rainstorm affect the weather on the mainland? The answer is possible. Because the westerly wind belt is a continuous airflow system, changes in its upstream can affect the weather downstream. This anomalous deep trough was formed due to a violent oscillation of the westerly wind belt, which may persist for some time, causing changes in the position and strength of the westerly wind belt, which will affect the weather on the continent.
If the westerly wind belt fluctuates further eastward, more cold vortices may form on the mainland, bringing frequent cold vortex thunderstorms and cooling, and if the fluctuations are introduced into the southern branch westerly winds south of the Tibetan Plateau, inducing the formation of the southern branch trough, it may cause more rainfall in the central and eastern parts of the continent. Of course, these situations are all possible, not necessarily happening, and not necessarily at the same time, depending on the actual changes in the westerly wind belt and the influence of the continental topography, oceans and other factors. However, we must be vigilant against the abnormal oscillation of the westerly wind belt, pay attention to the weather forecast in time, and take preventive measures to reduce the loss of disasters.
Overall, this rainstorm event in the Arabian Peninsula is a very rare extreme weather phenomenon that demonstrates the impact of global climate change and also serves as a reminder of the changes in the westerly wind belt, as it affects the weather not only in the Middle East but also on the continent.