A late-march peak bloom is currently forecast for the National Cherry Blossom Festival on the National Mall in Washington, D.C.

With March Madness here, and office pools under way, perhaps there should be a pool for when the cherry trees on the National Mall will reach peak bloom? The National Park Service thinks it will arrive between March 27-31.

Those dates are a moving target, of course. And with a spring snowstorm heading towards the Capital, it could get moved again. That's because the blooming experts use recent temperature data, the current progression of the blooming phases, and the weather forecast for the next ten days in calculating when the peak bloom will arrive. On Monday the Park Service forecast the start of the peak bloom period of the cherry blossoms will now occur during March 27-31.

On March 1, the peak bloom was projected to start between March 17 and 20. While the mathematical models still show the blossom reaching peak on March 18, this week’s cooler than forecast temperatures have necessitated moving the projection to the last week of March, the Park Service said.

Peak bloom occurs when 70 percent of the Yoshino cherry trees, the most abundant of the 12 species around the Tidal Basin and East Potomac Park, are in bloom. Once in bloom, the flowers can last for up to 10 days, depending on weather conditions. Additional varieties of trees bloom later than the Yoshinos. For example, the start of the peak bloom period for the Kwanzan trees is currently projected for April 10.

For current information on the cherry blossoms, including progression of the bloom process and a schedule of events for the National Cherry Blossom Festival, see this website.