Cornus mas does bloom a little earlier than Forsythia, but their bloom season does overlap some. Cornus mas is more like a tree with a rounded crown than a blowsy shrub and more refined in habit than forsythia.

I would guess what you saw was hamamelis - witchhazel. Most are a shade of yellow or orange and bloom before forsythia. They are in nearly full bloom around here right now.

Cornus mas is just opening here, in zone 7, but held back, because we are near the ocean. Springs are late.
The yellow Witch-hazel 'Arnold Promise' has been blooming for two weeks. My wife did say 'did you notice the forsythia?' Cornus officianalis is like C. mas but about two weeks earlier. It can be quite shrublike.

Here the sequence is Hamamelis > Cornus > Forsythia, the Hamamelis starting in (Dec.) Jan.

Thanks everyone, I will have to go take a closer look, I didn't even think about it being Hamamelis!

Sarah

Yup, sure enough its Hamamelis!!! Thanks!