Weather ahead

I was intending to sow salad leaves, rocket and parsley in my raised beds this weekend. I cant decide whether to do so now having seen the weather forecast. Should I continue on the premise that the weather is OK to sow today and tomorrow and I might not be able to get into the garden later on, or should I wait until after the cold spell and hope that there is a good window of opportunity later? Your thoughts?

I'd leave it a week before sowing anything outside. The weather is basically going back to mid January next week and temperatures could be below average for some time.