Howard, who can play either tighthead of loosehead, will be back in Hartlepool as soon as Box Hill's season is effectively over which is likely to be next month.
West coach Kevan Oliphant says: "We've kept in touch with Adam and there is no doubt that his game has benefitted from playing in Australia.
"Now he is looking forward to putting on a West senior shirt for the first time."
He will join former Rovers' second row Dean Cook ,and former Falcons and Mowden back row Matt Holmes, as new boys fighting fior places in the pack. Chocky Davies is also back in training with both Paul Vinnicombe and Iain Robinson moving on to play at a higher level - at Blaydon and Westoe respectively.