Suddenly(?) it's raining heavily in Seoul.

I knew there was a forecast for rain in the evening by checking the weather.

I thought I would come a little and then stop, so I put it in my umbrella bag, and now it's pouring rain..?

Still, it should be okay when you leave work, right...?

I heard a loud sound from the window, so I looked to see what it was, and it turned out to be the sound of rain;;;