I marked that one plant and checked back on March 20. Not a whole lot of difference but for the swelling of the flower, the thinning of its enclosure and the unmistakable yellow showing through.
Now, a week later on March 27, the flower is fully open. We've had pleasantly cool weather - even cold at night - but a few showers have brought the bulbs to life. The meadow is alive with sunshine even as it rains!