Its definitely a Cucullia sp. and i also think it is umbratica. But, as you just described how the caterpillars look like, you might have a picture of it? For it can be much easier to differentiate the Cucullia species using their larvae.
Otherwise, you can have a look on this overview of different larvae: http://lepiforum.de/lepiwiki.p…rsicht_Cuculliinae_Raupen