Normal rules and time lines are not going to apply this year because of the unusually warm season we have had. We haven't had any major storms or blizzards during this mild winter. Some trees are already budding and bulbs are already peaking out from the ground. Kansas City has had thunderstorms that remind you of spring, as well as other states seeing tornadoes.
Your yard will benefit from mowing the grass within the next couple of weeks. You need to cut it down about an inch shorter then what you normally would. It would also help to bag all of those clippings left over from mowing. Clean up all of the leaves left over in your landscaping or yard as well. Now is also a great time to also think about trimming back or dead heading most perennials and shrubs. Trim your trees as well, the goal is to establish a central leader “the trunk”. Remove anything growing down, into another branch, or that is unhealthy.
Crab grass will germinate when the soil temperature reaches 55 degrees for 3 consecutive days. When this happens, pre emergent for summer annuals will no longer have much of an affect. We normally hit this mark sometime around April but I wouldn't be surprised to see it come by mid March. Because of a prolonged summer annuals season most of the industry has moved over to doing 2 pre emergents, 1 early spring, 1 late spring. A similar treatment can be done in your landscaping beds to help prevent weeds. At this point I would personally wait on any major seeding for your yard.