On average, that occurs about 16-21 days before peak bloom. In 2014, it happened on March 23 and ended up being 18 days before a peak bloom of April 10. In 2013, it came on March 17 and ended up being 23 days before a peak bloom on April 9.
It's a beautiful spring morning. There have been some definite signs of progress over the past few days, but still no flowers. The weather and temperatures more typical of spring that we've had this week have helped move things along. More daffodils are coming out around town, and the tulip magnolias near the George Mason Memorial (near the Tidal Basin) aren't out quite yet but look as though their first flowers are ready to come out in the next few days.
On the cherry blossoms, we're starting to see some of the natural variations in timing from tree to tree, as you can see in the photos below. That's entirely normal as some trees inevitably start a little before others. There are also some photos of the indicator tree below. I walked the entire perimeter of the Tidal Basin this morning and didn't find any blossoms out, but there are few trees getting noticeably closer.
The traffic restrictions haven't gone into effect on Ohio Drive yet. My guess is that'll change this weekend as visitor traffic grows over the Easter weekend, so it might be worth building that into your planning if you're coming down then. Sunday is the lighting of the cherry blossom lantern. You can find more details about it here. There's still work being done on the Reflecting Pool, and it's still drained.
There haven't been any changes in the peak bloom forecasts so far, but the NPS arborists are of course watching the trees closely, and several of them were out and about early this morning. It wouldn't shock me if the forecasts get pushed back by a day or two, but no changes have been announced yet. If the peak bloom does come within the current forecast ranges, it's looking like it'll be towards the end of them. The current weather forecast for the week ahead looks quite nice but without any scorching temperatures that can speed things up rapidly. You can keep on top of the latest peak bloom forecasts here. And now that we're getting close, this page on what you might expect to see up to a week before peak bloom might be of interest.
If you're coming in to town this weekend (April 4-5), unfortunately it looks like it's going to be too early for most of the cherry blossoms. It's still possible some early flowers might spring out, but if they do they'll be scattered and you'll have to go hunting for them. If you have a choice of Saturday or Sunday down at the Tidal Basin, Sunday is probably a better bet simply because the extra day will give just that little bit of extra time. The weather forecast is also better for Sunday (and it'll probably also be more crowded).
Finally, I sometimes get asked about photo tours and photo walks. I don't offer them, but I'd recommend giving David at Washington Photo Safari a call. He's an expert professional photographer and takes small groups for cherry blossom photo walks to the best spots and helps you get the most out of your camera. The sunrise tour is an especially good option--it's a beautiful time of day. I ran into him down at the Tidal Basin with a group this morning, and he still has some slots open for mid-April around when the cherry blossoms should be in their prime. You can find his contact info here. (I don't have any affiliation with Washington Photo Safaris.)
The Indicator Tree
This tree, which has become known as the indicator tree, reliably blooms a week to ten days ahead of the others. Here's how it's looking as of this morning. I've also posted a detailed guide on how to find it.
These are over by the George Mason Memorial and typically come out a bit ahead of the cherry blossoms. They're not flowering yet, but it's looking like they might start to open over the next few days.
World War I Memorial Trees
There's a small group of fruit trees (perhaps plums) blossoming near the World War One Memorial. You can find information on how to find them here.