In reply to onesteptwosteps:
I am lucky to be able to make my decisions after looking out the window and then I just travel a few miles. I still need to use the essential element of a good winter climber's decision process though: FLEXIBILITY.
Be as flexible as you can with timings and locations. Generally, if you can organise that flexibility for just one month out of twelve then it has to be February. Sometimes that will go wrong too but not often.
What will help is to learn more about weather forecasting and learn to use the medium range forecasts that are now very good. If you are feeling flush you might want to hand Piers Corbyn a wad of cash and ask him to pick you a good week.
Go to http://www.kintailmrt.org.uk/conditions.htm and click on the middle button (Longer ... ). On Snowforecast you get 6 days free and 9 if you pay a small fee. WXmaps provides good detail out 6 days if you learn how to read the right stuff such as the 540/528dam lines for 1000/500mb air density and the 0C at 850mb line. The more of these forecasts you examine the more accurate a picture you will get of the weather up to a week ahead. Out beyond a week, things get sketchy. This is where your February flexibility comes in!
http://www.kintailmrt.org.uk/kmrt01.htm
http://www.kintailmrt.org.uk/kmrt01.htm
http://www.kintailmrt.org.uk/kmrt01.htm