The weather predictions from NOAA is pretty close compared to mountain-forecast.
NOAA forecasted afternoon showers for Friday (9/9), Sat (9/10) and Sunday 9/11.
It was raining (not heavy) on Friday evening at portal campground, and again rained on Saturday evening at Outpost camp.
Sunday, we started the hike from outpost at 1.30am and reached the summit by 8.30am. Weather was excellent. But by the time we were at the bottom of switchbacks, the clouds were covering the summit (but people were going up hill). We reached the parking lot at 4.45 pm and didn't see any rain until that time.