The development, which started in the depths of the Pacific Ocean and appeared to be an ordinary marine movement at first glance, soon attracted the attention of scientists. The massive movement under the ocean not only changed the temperature of the sea, but also stirred up the atmosphere. Then, chain changes that could affect weather conditions in different parts of the world began to emerge.
While the picture in front of scientists becomes more and more remarkable, the common message from climate models has also increased concerns. According to the news in the New York Times, it seems that the impact of what happened will not be limited to the Pacific. Moreover, the main point that experts draw attention to is how long the event can continue as well as its magnitude. Forecasts indicate that the weather pattern to which the world is accustomed may change significantly in the coming period.
So what exactly is happening in the Pacific and how will this extraordinary movement affect the rest of the world?
'GIANT WAVE' PROGRESSING UNDER THE PACIFIC
In March, satellite sensors began detecting an unusually large wave in the Pacific Ocean moving eastward along the Equator. This movement was associated with a huge mass of water moving from the depths of the ocean to the surface and trying to reach the shores of South America.
As the wave moved eastward, significant changes in sea level and ocean temperature occurred. The warm water carried from the depths of the ocean approaching the surface began to change the temperature balance in the eastern and central parts of the Pacific. The most striking development was that this was not limited to the ocean only. The warming sea surface began to warm the air above it and transfer more moisture to the atmosphere. As large thunderstorms formed over the Pacific, the energy created by these storms triggered large-scale fluctuations in the atmosphere.
These fluctuations in the atmosphere soon spread far beyond the Pacific. Thus, the change that started in a certain region of the ocean turned into a global process that could affect temperature, precipitation and storm systems in different parts of the world. El Nino, which has been followed by the scientific world for a long time, has gained much strength with this mechanism.
NEW DETAILS ABOUT EL NINO ARE A LITTLE CONFUSED
One of the most notable developments in El Nino research in recent years is that scientists are looking more closely not only at the temperatures on the sea surface, but also at the warm water masses carried hundreds of meters deep in the ocean.
Because behind the temperature change seen on the surface, there may be a huge amount of heat accumulated in the depths of the ocean for a long time. These hot water masses can move towards the surface when suitable conditions occur and significantly change the energy exchange with the atmosphere.
Therefore, for experts, the only question is “How warm is the sea surface?” The question is not enough. How much warm water there is in the depths of the ocean, which direction it moves and how much of it will rise to the surface are also of great importance in understanding the future of El Nino. New observations indicate that the deep layers of the ocean may be more important than previously thought in understanding major changes in the atmosphere.
THE STRONGEST EL NINO EVENT IN HISTORY IS COMING
Kırşehir Ahi Evran University Geography Department Lecturer Assoc. Dr. When I consulted with Doğukan Doğu Yavaşlı, he stated that the strong El Nino expectation has not changed and said, "The latest observations and seasonal forecast models in the tropical Pacific indicate that a strong El Nino event may develop in the second half of 2026. The forecasts have not changed, they continue strongly. A significant part of the models are approaching the super El Nino scenario."
One of the biggest concerns of climate experts is the re-emergence of the consequences of the strongest El Niño event on record, which occurred in 1877-1878.
Assoc. Dr. Doğukan Doğu Yavaşlı said, "The 1877-78 event is the strongest El Nino on record, as calculated from the proxy data of the pre-modern measurement period. Some models for 2026 predict a peak around +3 degrees in the Nino 3.4 index. This figure indicates a signal strong enough to leave the 1997-98 and 2015-16 events behind. In other words, we may be faced with a picture similar to 1877 in terms of the physical magnitude of the event." used.
WHAT AWAITS EUROPE?
One of the most important features of El Nino is that its effects are not the same everywhere in the world. While rainfall decreases in some regions, there may be much more rainfall than normal in other regions. This situation can cause the risk of both drought and flood to increase on a global scale.
There is a remarkable prediction, especially for the southeast of the USA. It is stated that the probability of above-normal rainfall in the October-December period is over 70 percent.
What is expected to happen in Europe is a little more complicated. Changes in atmospheric circulation, especially during winter months, may cause temperature and precipitation patterns to differ from normal in some parts of Europe. While drought, hot weather and increased risk of forest fires are prominent around Southern Europe and the Mediterranean, wetter and stormier periods can be seen in the northern and western parts of the continent. These changes can put pressure on agricultural production, water resources, energy demand and transportation.
WHAT KIND OF AUTUMN AWAITS TURKEY?
The real question for Türkiye is how strong El Nino will change the temperature and precipitation patterns in autumn and winter.
Meteorological Engineer Dr. working at Istanbul Aydin University. Lecturer According to member Güven Özdemir, it would not be correct to define the coming period in Turkey as 'dry' or 'rainy' alone. Özdemir stated that Turkey is likely to have a warm but occasionally very rainy autumn and made the following assessment:
"There is a strong possibility that the autumn of 2026 will not be a classically constantly rainy or constantly dry season for Turkey, but instead will be a period in which temperatures are above normal in most periods, but precipitation can be intermittent, irregular and occasionally extreme. Especially in the Marmara, Aegean, Black Sea and Mediterranean coasts, short-term heavy rainfall and flash floods, and in some parts of Southern and Southwest Anatolia, periodic rainfall deficit and drought risk need to be monitored together."
EL NINO ALONE WILL NOT BE DETERMINANT BUT…
Güven Özdemir also pointed out that El Nino should not be considered as a determining system on its own and said, "Instead of seeing El Nino as a 'drought' or 'rain-bringing' system, it should be evaluated as a trigger that changes the large-scale circulation of the atmosphere. The extraordinarily strong El Nino in 2026 increases the likelihood of its effects; however, the amount and distribution of precipitation in Turkey will be affected by the phase of the North Atlantic Oscillation (NAO) in the Mediterranean Sea in the last stage." "water temperatures, high/low pressure centers over the Balkans and the location of the jet stream will be decisive," he said.
For this reason, it will not be sufficient to only look at the total amount of precipitation in evaluating the coming period for Türkiye. The critical point emphasized by Özdemir is the timing and intensity of the rain:
“Therefore, the main question to be monitored in the coming months should not be: 'Will Turkey be dry or rainy?'; it is 'where, when and to what intensity will the precipitation fall?'. As a matter of fact, the current MGM seasonal forecasts indicate that precipitation across Turkey will show significant regional differences in different periods of autumn and winter; the General Directorate of Meteorology (MGM) also states that seasonal forecasts take into account factors such as large-scale El Niño, NAO and sea surface temperature, but local and short-term meteorological events are affected by these models. It specifically states that it may not be fully represented by the
FLOOD RISK IN MARMARA AND AEGEAN, DROUGHT RISK IN MEDITERRANEAN
Güven Özdemir points out that different weather conditions can be seen at the same time for Türkiye in the transition from autumn to winter.
According to Özdemir's assessment, "Three different risk areas need to be monitored simultaneously for Turkey in the transition from autumn to winter in 2026. In the Marmara and Aegean regions, there is a risk of sudden and strong showers, thunderstorms and urban floods due to high sea water temperatures, high humidity and upper-level cold air transitions. If the high pressure periods are prolonged in the Mediterranean and Southwest Anatolia, the risk of above-normal temperatures, precipitation deficit and drought may come to the fore. In Central Anatolia, the risk of above-normal temperatures, rainfall deficit and drought may come to the fore." "If precipitation is distributed unevenly between systems, a long-term precipitation deficit followed by short-term heavy precipitation may occur."
Apart from this table, the Black Sea may be one of the more advantageous regions in terms of rainfall. Özdemir said, "In the face of this, it can be expected that the Black Sea region will be more advantageous in terms of precipitation. As a matter of fact, in MGM's December projection, precipitation on the Black Sea coast is predicted to be above normal."
For this reason, instead of reading the impact of strong El Niño on Turkey solely in terms of temperature increase or drought, it is necessary to evaluate it in terms of the atmospheric circulation becoming more wavy and the temporal and spatial distribution of precipitation deteriorating.
THE WORLD HAS A CRITICAL 10 MONTHS AHEAD
The effects of El Nino will not be limited to meteorology alone. Chain consequences may occur in a wide range of areas, from food prices to electricity consumption, from water resources to health services, from agricultural production to international trade.
Drought can reduce agricultural production, and excessive rainfall can damage cultivated areas. As heat waves increase electricity demand, the pressure on water resources may also grow.
Transportation infrastructure, the insurance industry and global supply chains can also be directly or indirectly affected by extreme weather events.
Therefore, governments have to review disaster plans, businesses have to strengthen their supply chains, energy and water companies have to evaluate capacity scenarios, healthcare systems have to prepare for heat waves, and local governments have to inform citizens about possible risks in a timely manner.
WHAT WILL THE WEATHER BE THIS WEEK?
Güven Özdemir also made evaluations about the weather systems expected to affect Turkey throughout the week. Özdemir said that the low pressure centers that are effective around Italy and the Central Mediterranean and the cool weather coming over the Balkans will be decisive in the weather conditions, and stated that rainfall and strong winds may be effective, especially in the Marmara and Aegean regions.
Güven Özdemir stated that the meteorologically prominent development of the week was the movement of low pressure areas originating from the Mediterranean and their associated front systems to the east, and added that the interaction of the Icelandic low pressure with the cool air that will reach Turkey via the Balkans will also have important results.
Noting that low pressure centers support rising air movements, Özdemir stated that cloudiness and precipitation occur as the rising air cools and condenses, and that thunderstorms can develop if there is sufficient humidity and temperature difference in the lower and middle levels of the atmosphere.
RAIN AND COOL WEATHER WILL BE EFFECTIVE IN MARMARA
Stating that the main agenda of the week in the Marmara Region will be rainy and cool weather, Güven Özdemir said that heavy rains that may start around Thrace and Çanakkale may also be effective around Istanbul, Kocaeli, Sakarya and Bursa. He added that winds blowing from north and northeast directions may become stronger from time to time.
Meteorological Engineer Dr. working at Istanbul Aydin University. Lecturer Member Güven Özdemir
DAY-TO-DAY WEATHER IN ISTANBUL
Güven Özdemir explained day by day what the weather will be like in Istanbul this week:
Today: The effect of the rainy system will become evident. While intermittent showers are expected, the daytime temperature is expected to drop to approximately 20-21 degrees. As the northern winds become stronger, the weather will feel cooler.
Wednesday, October 14: One of the most important days of the week that should be watched carefully. There is a high probability of rain in Istanbul. While the rain is expected to increase its effect, especially in the afternoon and evening hours, there may be a risk of flooding with heavy rain. The temperature is around 17-18 degrees. However, it is not possible to precisely determine in advance the districts and times when the precipitation will be heaviest.
Thursday, October 15: Rainfall may continue at night and in the morning. Cloudy, cool and windy weather will prevail during the day. The daytime temperature is expected to drop to around 16-17 degrees.
Friday, October 16: It is possible that the rain will continue intermittently. As temperatures hover around 16-17 degrees, it will be seen that the summer weather of recent days has completely disappeared.
Saturday, October 17: There is a high probability of showers again in Istanbul. It will be possible for the daytime temperature to remain around 15-16 degrees and the night temperature to decrease to 11-13 degrees.
