Second image displays the bright yellow hind-wing. The resting position of this species is the 'tent' position but when flying the hindwing colour is more obvious. Five came to the light despite the cold night air.
This species is variable. It can be dark grey or lighter grey with black lines. It can also have light brown markings on both forewing and hindwing (see next observation). Largish moth; eight appeared at the light-trap.