Istanbul: An “omega blocking” weather pattern over Europe has trapped heat across the continent, fueling an abnormal heat wave and pushing temperatures to record levels in several countries, according to Prof. Mikdat Kadioglu, climate and meteorology expert at Istanbul Technical University.
According to Anadolu Agency, several European countries, including France, the United Kingdom, Belgium, the Netherlands, Spain, and Italy, have faced record-high temperatures in recent days. Italy has issued red alerts in eight cities due to an Africa-origin heat wave, while Spain experiences significant disruptions in daily life, particularly in Granada, due to soaring temperatures.
French weather agency Meteo-France has warned that temperatures could reach record levels between June 21-23, with 60 departments under orange alert, and extreme heat is expected to continue into next week. In Amsterdam, meteorologists forecast tropical levels of heat, with some areas expected to exceed 30°C (86°F). Belgium’s Royal Meteorological Institute also issued an orange alert due to extreme heat and severe storms.
The UK Met Office anticipates elevated temperatures to persist through Thursday, with some areas forecasted to exceed 30°C, and the hottest regions potentially reaching 38°C. Discussing the phenomena with Anadolu, Kadioglu explained that a massive ridge of high pressure shaped like the Greek letter Omega has settled over Europe, creating an ‘omega block.’
“This pattern consists of a strong warm ridge in the center, flanked by low-pressure systems on both sides,” he stated, adding that the system has effectively blocked weather patterns from progressing west to east, trapping heat over Europe while countries like Trkiye remain cooler and wetter.
Kadioglu emphasized that the current heat wave is not a typical summer event, noting a clear difference between ordinary summer heat and a heat wave strengthened by atmospheric blocking. He detailed that in an omega block, a large high-pressure ridge becomes locked over Europe, causing the air to descend beneath the ridge, keeping skies clear and allowing the sun to continuously heat the surface. Consequently, heat accumulates in the same area for days.
He noted the unusual nature of the event lies in both its timing and geographic reach. “For such intense heat to arrive this early in June and extend as far north as Scandinavia and Norway means temperatures are significantly above seasonal norms. This is not a normal summer day but an abnormal heat wave reinforced by atmospheric blocking,” he said.
Kadioglu remarked that while heat waves are a natural part of summer, this event is amplified by persistent atmospheric blocking, which has become more frequent and severe in recent years. “The highest risk is in Western and Central Europe, including France, Spain, Germany, the Benelux countries, the UK, and also Scandinavia and Norway, where the warm flow extends northward,” he warned, highlighting the potential increase in drought conditions and elevated wildfire risk due to prolonged high temperatures.
Trkiye currently finds itself in the cooler, wetter eastern zone of the omega block, shielded from the extreme heat impacting Europe between June 21-26. Kadioglu noted that northern airflows have pushed temperatures below seasonal norms in some regions, while inland, northern and eastern areas face risks of localized thunderstorms, hail, and sudden strong winds. He also cautioned about the potential for flash floods and waterlogging, particularly in the Black Sea region.
If the trough deepens into a cut-off low and stalls over the Black Sea, repeated rainfall over the same areas could significantly increase flood risk. Conversely, coastal Aegean and Mediterranean regions, along with southeastern Trkiye, are expected to remain hotter and drier. Rising temperatures in Trkiye are likely after June 25-26 as the trough weakens.
Kadioglu pointed out that rising temperatures and earlier heat events indicate atmospheric blocking patterns are becoming more frequent and persistent. “The fact that heat is reaching higher latitudes such as Scandinavia, where such temperatures are uncommon shows the baseline temperature of the atmosphere is rising,” he stated, adding that while a single event does not define climate, repeated record-breaking heat waves indicate a clear trend.
Europe’s heat wave may ease toward the end of June as the blocking pattern weakens, while Trkiye is expected to warm further heading into July and August. Above-normal temperatures, periodic heat waves, drought, and elevated wildfire risks are likely during the summer.
Kadioglu cautioned that these blocking patterns might repeat throughout the summer, with each new blocking event potentially placing either Europe or Trkiye under extreme heat. He emphasized that climate change is not the direct cause of a single heat wave but increases the likelihood, intensity, and duration of such events. Global warming has raised baseline temperatures, meaning the same atmospheric blocking pattern now produces higher peak temperatures than it did 10 to 20 years ago.