The blossom forecast ( æ å ç sakurazensen , literally `` cherry blossom front '' ) is announcement each year by the Japan Meteorological Agency , and is watched with attention by those who plan to celebrate hanami because the blossoms last for very little time , usually no more than two weeks . The blossom forecast ( æ å ç sakurazensen , literally `` cherry blossom front '' ) is announced each year by the Japan Meteorological Agency , and is watched with attention by those who plan to celebrate hanami because the blossoms last for very little time , usually no more than two weeks .