The plum blossoms (Ume) have been blooming for several days.That means that the cherry blossoms (Sakura) are next. The cherry petals are luminous and irridescent which gives them an edge on beauty as compared with the plum blossoms. Not to mention that it should be slightly warmer 3 weeks later when the cherry blossoms arrive and this must also contribute to their popularity.
Forecasts for 2010 for the Nikko region are around April 1st. Keep in mind that Nikko, Tochigi is a large mountainous region. The difference in elevation between Toshogu Shrine and Chuzenji Lake is around 600 meters, so it is cooler near the lake and therefore the blossoms may bloom slightly later.
An added bonus this year is that the full moon (mangetsu) is on Tuesday, March 30th, 11:30 am in Japan. Monday night would be slightly better than Tuesday night as the Moon will rise minutes before sunset. If the weather is cold, then it might be harder to wait those few extra moments on Tuesday night. It would be fate if we could have the full moon and full bloom (mankai) together on the same night.
Keep your schedule open at this time of the year and be ready to have a cherry blossom party (hanami) on any night. It is quite rare that it lasts two weekends in any location. Enjoy the moment. The petals are delicate and will fall to the ground if it is windy or if it rains.