Complex sentence: On June 2,2007, Allen began filling in as weather anchor on WNYW, originally a short tenure with the station... doing weekend weather forecasts for fourteen out of eighteen weekends, starting with the June 2nd broadcasts.
Split into simpler sentences: On June 2,2007, Allen began filling in as weather anchor on WNYW, a short tenure with the station. He is expected to do the weather forecasts for fourteen out of eighteen weekends, starting with the June 2nd broadcasts.