Fall River is seeing an afternoon BWO hatch (#18-20 and go heavy on emergers and cripples) mixed with some really small black midges (#22-24) and assume a decent chance of seeing some larger amber caddis (#12-14) here and there. 
Eggs, Zebra Midges, Perdigons, Dark/Small/Heavy Mayfly Nymphs, Caddis Pupa, Leeches, Euro Streamers and Orange Rufus are good pattern choices all winter long. 
It’ll be a good week to enjoy the Fall River with today being the coolest day on the forecast, with mid-week looking quire nice and end of the week maybe some snow showers coming back to the forecast.