The Istanbul Governor's Office issued a warning of heavy rain and storms in the city based on assessments by the General Directorate of Meteorology. According to the announcement, showers and thunderstorms expected on the night of October 26 are forecast to become heavy from the morning of October 27, producing between 21 and 50 kilograms of rainfall per square meter.

Rainfall in the northern parts of the city, including Arnavutköy, Sarıyer, Beykoz, Eyüpsultan and Şile, is forecast to be very heavy, reaching between 21 and 75 kilograms per square meter. The heavy rain is expected to lose its effect in the evening of October 27.
Northerly winds are forecast to blow strongly at speeds of 40 to 60 kilometers per hour, occasionally reaching 70 kilometers per hour in the form of short-lived storms. Temperatures are expected to fall noticeably with the rain, dropping 3 to 5 degrees below seasonal averages.
The Governor's Office urged residents to remain cautious and take precautions against possible adverse conditions, including flooding, waterlogging, strong winds during rainfall and disruptions to transportation.