What type of front is ociated with this weather pattern?

Today where I live there were ulus clouds occasionally covering the sun and the sky was full of them throughout the day. The midday temperature reached about 76 degrees and there was an occasional light breeze. During the late afternoon and early evening the sky clouded over with a blanket of dark clouds (almost like stratus clouds, but darker), and about an hour after the clouds covered the sky a steady drizzle began. It has been raining lightly, yet steadily ever since (about an hour later). I was wondering whether this is a cold front or a warm front. I think it's a warm front but my friend disagrees.