Monday, April 3, 2017

Post-winter Recovery

Springtime is making its way uphill in the Sierra with redbud peaking in El Portal now while unfathomable snow persists above 7000 feet. It can hardly be said enough: WHAT a winter we've had here! Storms were repeated with good frequency and lots of Pacific moisture, leaving us with a tremendous snowpack. The snowline was a bit higher than historical averages; not much accumulated in Yosemite Valley (though we had lots of rain runoff), but higher elevations have had fantastical quantities. The central Sierra has 175% of usual water content in the current snowpack. Picture the meadows and forests in the May Lake area buried by 6-7 feet of water (not 6' of snow, but 6' of standing water) - that's the nature of how much mature, dense snow is covering the tens of thousands of acres of Yosemite's upper elevations.

<-Bridalveil in flood.

Storm damage has been considerable in/near the park, with Hwy. 41 having been closed for a month by a washout, and crews working hard to repair slope movement on the Big Oak Flat Road below Crane Flat in hopes of getting it re-opened before Memorial Day. Trails at and above the Yosemite Valley level have a lot of downed trees; trail crew sawyers will be very busy for much of the summer to get those cleared. When you visit the Valley, check out the fragments of bark-less logs below Bridalveil or Yosemite Falls from trees that were uprooted and thrown over the falls this winter. Since December there's been a huge deposit of frazil (wist) ice below Yosemite Falls, and we're now in the month when one is most likely to be able to observe wist ice flowing.

The excitement isn't over. Because of the closure of the Big Oak Flat Road, Hwy. 140 has been handling much more traffic. This past Saturday, visitors were waiting over 2 hours in a 3.5 mile-long line of 800+ cars just to get through the stoplight at the Ferguson rockslide detour west of the park. (Easily avoided by coming in before 9am on weekends.) Because of the road construction in the Valley, the main parking at Yosemite Village will be closed for the next two months, and detours are confusing to both new and veteran visitors. It's going to be a very nice improvement once it's completed, but parking and navigating can be challenges on spring weekends now. Half Dome Village and the new lot by Camp Four are best bets. The road crew is already working to clear Glacier Point Road.

But, wait, there's more. The Merced is running almost 4x average flow today. All that snow in the high country seems likely to bring us some degree of 'high water incident' between now and mid-June (sure to cover some Valley trails at least), depending on how the warming progresses. Yosemite explorers should expect a delayed start to summer, with Tioga Road opening late, trails covered by snow and fallen trees, and creeks difficult to cross.