Saturday, March 19, 2011

Wintery Equinox

Yosemite Valley's mostly bare ground got a few inches of snow overnight and it even accumulated as low as El Portal; most park roads are R2 this morning. Another wave of snow arrives early Sunday morning.
We had frazil ice in the Valley this week, with Yosemite Creek sending frazil into the Merced twice, and Ribbon Creek even fraziling all the way into the river on Thursday. The snow cone at Upper Yosemite Fall is as big as ever. Frazil forecast for the next several days: moderate, best on Monday morning.
Sentinel, Eagle and Horsetail Creeks flow to the river. Wosky Pond is very full.
Varied thrushes, which have not been very evident here this winter, were making their odd squeaks in Yosemite Village yesterday. Karen Amstutz and Michael Ross heard and saw a phainopepla in El Portal earlier. Karen noted a disoriented flock of Canada geese in the rainy nighttime of Badger Pass last weekend, likely drawn to the illuminated slopes.
Tonight's full moon coincides with perigee (the point in its elliptical orbit where it's closest to earth) so will appear a bit larger and about 15% brighter than an average full moon; this happens about every 20 years. Elsewhere in the sky this weekend: vernal equinox on Sunday when the sun rises due East and sets due West, and our day and night are about equal in time. Vernal means springtime, so Sunday is the first day of astronomical spring for the northern hemisphere. Vernal also is a big waterfall that will be running strong this season - given its current name by the first Euro-Americans in the Valley who saw its ferns and moss as springlike. Just upstream was a bigger, but somehow colder-looking waterfall that they named Nevada, meaning snowy.
This weekend is thus both 'vernal' in astronomy and 'nevada' in weather - Yosemite perfection.

1 comment:

  1. i would love to be in the park now (and always) - huge moon, fresh snow, frzil ice.....lucky you.