The tropical season in the Arabian Sea is under the influence of the La Nina phenomenon.. Does this portend a less active tropical season than usual?

Arab Weather - Meteorologists at the Arab Weather Regional Center are following the latest outputs issued by global maps of water surface temperatures, which indicate that the "La Niña" phenomenon is developing slowly during this period. "La Niña" is characterized by a decrease in sea surface temperatures in the tropical Pacific Ocean, which can affect global climate patterns in multiple ways. Its potential effects include changes in rainfall patterns, as it may lead to an increase or decrease in precipitation in different regions, as well as its impact on temperatures and hurricanes.

The probability of the La Niña phenomenon developing is more than 70% during the fall season, coinciding with the second tropical conditions season in the Arabian Sea.

The latest climate forecasts and reports issued by global centers, specifically the NOAA Atmospheric and Oceanic Monitoring Agency, indicate a 71% probability of the development of the "La Niña" phenomenon during the period from September to November 2024, i.e. during the current fall season. It is likely, with a high probability of 74%, that it will continue during the winter season in the Northern Hemisphere. It is known that the La Niña phenomenon greatly affects the tropical cyclone season around the world, including the tropical cases season in the Arabian Sea, which naturally develops during it. The second season of tropical cases activity in the North Indian Ocean begins in October and November, and is called (Post-monsoon), i.e. the season that follows the monsoon activity in the Arabian Sea. This does not mean that there is no possibility of tropical cases activity at another time of the year, but the previous two periods are considered the peak of tropical cases activity in the Arabian Sea.

Scientifically, the La Nina phenomenon greatly affects the tropical conditions season in the Arabian Sea.

Meteorologists at the Arab Weather Center said that the La Niña phenomenon causes changes in the temperature pattern and behavior of the atmosphere, which affects the development and frequency of tropical conditions. The following are some of the main effects of the La Niña phenomenon on the tropical conditions season in the Arabian Sea:

Lower sea surface temperatures: During a La Niña, sea surface temperatures in the tropical Pacific Ocean are lower than normal, affecting the overall distribution of heat and moisture in the atmosphere, including the Arabian Sea. The waters in the Arabian Sea also tend to be relatively cooler than normal, reducing the chances of tropical conditions developing into strong cyclones.

Increased upper wind shear activity: On the other hand, La Niña is often associated with increased upper wind shear activity in the Arabian Sea, which is wind that changes speed or direction with height. Strong upper wind shear breaks up and fragments the tropical system, preventing it from developing into strong cyclones or even deep tropical systems.

High atmospheric pressure: La Niña also causes high atmospheric pressure in the Arabian Sea region. This creates an atmospheric environment that is unfavorable for cloud formation and convection necessary for tropical systems to develop. High pressure also limits the flow of moisture and prevents tropical storms from forming.

Jet stream effects: La Niña also causes the jet stream to move in the atmosphere in a way that enhances surface winds coming from neighboring continents such as India, which carry dry air to the Arabian Sea. This dry air hinders the formation of thunderstorms and tropical activity.

Shorter and less active season: La Niña typically causes fewer tropical storms in the Arabian Sea and shortens the tropical season. There are typically fewer cyclones and tropical storms than in years with El Niño, which is more supportive of cyclone activity in the Arabian Sea.

God knows best.