Between 4 and 7 September 2023, heavy floods occurred from torrential rain as Storm Daniel hit Southeast Europe including Turkey, Greece and Bulgaria. At least 22 people were killed and 4 others went missing. Those events were due to an Omega block, as a high-pressure zone became sandwiched between two zones of low pressure, shaping a Greek letter Ω

⚠️ ΕΚΤΑΚΤΟ ΔΕΛΤΙΟ ΕΠΙΚΙΝΔΥΝΩΝ ΚΑΙΡΙΚΩΝ ΦΑΙΝΟΜΕΝΩΝ ✅Yψηλά επίπεδα βροχοπτώσεων με μεγάλη διάρκεια σε Θεσσαλία, Σποράδες, κεντρική και ανατολική Στερεά, βόρεια Εύβοια και Πελοπόννησο. ✅ΤΟ ΚΕΙΜΕΝΟ : https://t.co/T4PBDpYwQL ✅Η ΑΝΑΛΥΣΗ ΕΠΙ ΤΟΥ ΕΚΤΑΚΤΟΥ : https://t.co/5NxWiR4T8U — Theodoros Kolydas (@KolydasT) September 3, 2023 Floods in Greece On 5 September, at least one person died in floods in Thessaly, Greece.On the same day, the village of Zagora received 889 millimetres (2.917 ft) of rain, 55 times higher than the average rainfall for the same month across the country.In Portaria, new record amounts of rain were also measured at 884 millimetres (2.900 ft) per square meter; however, further rainfall could not be measured because the weather station subsequently failed.

On 6 September, the Krafsidonas river, which rises at Pelion, overflowed its banks in Volos and destroyed a bridge.

On 7 September, the main Greek motorway between Athens and Thessaloniki was closed and train services between the two cities were suspended. In Thessaly, buildings and bridges tore down and whole cities submerged, where over 800 people had to be rescued.In Larissa, after the rains ended on 8 September, the water continued to rise as the Pineios river overflowed its banks to reach a level of 9.5 metres (31 ft), compared to the normal at around 4 metres (13 ft).

Since the rainfall started, the Copernicus Programme's Rapid Mapping Service was activated for the flood zone in Greece, in which analysis of the Sentinel-1 data from 7 September revealed an estimated flood area of ​​around 73,000 hectares (180,000 acres) Meteorologists classified the storm as Greece's worst since records began in 1930.In addition, the floods in Thessaly, which supplies about 15% of Greece's agricultural production, destroyed the crops for the remainder of the year and caused serious long-term damage as the thick layer of mud would make the soil infertile overall.The governor of Thessaly, Kostas Agorastos, told the ERT that the storm damage in the region was valued at more than €2bn.

Turkey

In Turkey, five people were killed during the floods in Kırklareli, another two died in the Istanbul districts of Başakşehir and Küçükçekmece.

Bulgaria

Villages in Bulgaria were submerged, including Kosti and Arapya [ceb] with people being evacuated. Three people were swept away after a bridge collapsed in the Tsarevo area, Bulgaria, and another person also drowned near the town And after the impact of the Mediterranean storm Daniel on Libya, it is likely to continue moving towards northwestern Egypt in conjunction with a clear loss of strength and may cause thunderstorms on parts of the northwestern coasts of Egypt and Marsa Matruh, and may extend weaker to parts of the delta, although To continue its movement in the eastern basin of the Mediterranean Sea as a normal weather system.