Thursday, March 14, 2013


Thaw: It's really warm in the park this week.  The Merced River has increased its flow to well above average, but our runoff won't last very long this year.  The latest snowpack surveys indicate 68% of average water content for the Merced watershed.
Freeze: Despite the clear signs of spring, we are not beyond snow season yet. Vernal equinox is next Wednesday, but we still have two months of snowfall potential.   Frazil ice maximum in Yosemite Valley is still a month away.   Skiers have three more weekends to enjoy skiing at Badger Pass.
Thaw: In the lower canyon flowers grace the terrain with orange poppies, white popcorn flower, baby blue-eyes, and even the redbud are emerging in their unique purple.  Kinglets, flickers and Bewick's wrens are singing this morning, and three species of swallows have returned to El Portal.  Buckeyes are greening up.  Armadas of white-throated swifts are already sweeping the skies up to 5000'.
Freeze: Despite the scant snow, Tioga Road won't open any earlier this year.  To cut costs during the current federal cutbacks, NPS will delay the start of plowing.  XC skiers are still gliding at Crane Flat.

Lyell West Lobe
Thaw: I hope by now most of you have heard the news that higher up in the park our measurements of the Lyell Glacier indicate that it has stopped moving.  Technically speaking, a glacier is ice that moves.  Lyell had been the largest glacier on the west slope of the Sierra, but now that distinction falls to the adjacent Maclure Glacier.  The former Lyell Glacier might be properly called a glacieret or a glacial vestige.
Thaw/freeze: Comet Pan-STARRS is visible very low in the west after sunset.  It's not easy to get a low enough horizon in Yosemite to see this comet in the twilight.  Binoculars are key to spotting this comet, which will fade over the next couple of weeks. 
I'm excited about a special program on April 13 that brings together Muir's great-great-grandson and a Muir actor for a day of roaming John Muir's haunts in Yosemite Valley.  This will be a fun way to experience history in person.