The authorized Muslim authorities in Japan, Australia, Brunei, Indonesia and Malaysia have already announced that today the new moon of the month of Ramadan will not be observed and therefore tomorrow will be the last day of the month of Shaban in these countries and the month of Ramadan there will begin on Tuesday.
Arab sources report that in the skies of nine out of 10 stargazers in Saudi Arabia who are entrusted with the job of identifying the new moon for the Muslim clerics, there is heavy cloud cover that makes it impossible to observe the new moon.
Because of this, it is most likely that even in Saudi Arabia it will not be announced that the rise of the moon will be observed today. Nevertheless, the work of locating it there continues.
The International Center for Astronomy claims that today it is impossible to discern the new moon in any of the Muslim countries, either with the naked eye or with a telescope.
According to all of the above, the likely scenario is that the Sunni countries will declare that Tuesday is the first day of the month of Ramadan (the Shias have their own world and they usually like to differentiate themselves in this matter…).
I will update as soon as there is an official announcement.