I was surprised to hear someone using forecasted as the past tense of forecast in an NPR report this afternoon. I consulted all the dictionaries to which I have access either on-line and in my office. Each one gave forcasted as an alternative past and past participle of the verb to forecast. In language usage, there is always a strong tendency toward regularization, and I wonder if forecasted isn’t destined to replace forecast.
I visited the Mt. Lebanon Public Library to see if The Oxford English Dictionary offered any insight into past forms of forecast. Much to my dismay, the library seems to have deaccessioned its copy of the OED while keeping the update volumes. Dumping the OED is a tragedy, and keeping the updates is nonsensical. (From the update, I was given newer meanings for forecast but learned nothing of the word’s history.)