Wednesday, December 7, 2011

Aeolian transition

As did much of the West, Yosemite had a strong windstorm last week. The park had closed the Tioga Road in anticipation of problems and there were indeed numerous lodgepoles felled in the area near the Mono/Parker Pass trailhead (almost at treeline) and a few elsewhere. In Yosemite Valley there were some trees thrown down and many branches flung on Wednesday night. The last of the deciduous leaves were stripped off, though the Cascades area must've been a calmer pocket as there is still color there.
Along the FourMile Trail several large trees were knocked down (photo).
For the first time in many months the Merced River has dropped to below average flow and is as low as it's been in 14 months.
Six species of woodpeckers were observed by my birding group on Saturday, and a seventh just after we split up. Now we await the snows and look forward to getting out in the winter world.
Get up early on Saturday morning to find a spot where you have a good view of a low western horizon. The earth's shadow will eclipse the full moon as the moon sets; you should see it turn reddish-orange as the sky brightens to day.

Monday, November 28, 2011

Fall or Winter

It's a mild week in Yosemite but most trees are bare and there's morning frost in Yosemite Valley. Tioga Pass is open to cars but Glacier Point Road is closed. A Clark's Nutcracker drifted down from treeline and was heard above the Valley's west end, while aerial plankton of spiders and small insects fills the air in the afternoon sun.
Balloon flies continue to float in quantities in El Portal, where Grindella is still in bloom. Juncoes and mixed winter flocks have displaced the swifts and swallows of summer. Fresh bear tracks were seen in the snow at 7000' on Thanksgiving day.
I was just outside the park with friends yesterday and saw 4 river otters on the Tuolumne River. Park biologist SStock has records of 37 prior sightings of river otters in/near the park. They include observations from throughout Yosemite, including up to 10,000'. Has fish introduction allowed the otters to range higher or stay longer than pre-fish?
This weekend is the Conservancy's woodpeckers field course; we have more kinds of woodpeckers than almost anywhere. Good weather should make a pleasant day for a quest to see as many as we can while learning about this important keystone guild. Our Christmas Bird Count is December 18 and would welcome more participants, whether experienced birders or not. Maybe mild weather will last, though La Nina is expected to be visiting for the winter.

Thursday, October 27, 2011

So Autumn

The fall glow in the Range of Light is especially remarkable in Yosemite Valley these days. We are at that point in the sun's apparent migration in the sky when it sets very low in the west, in the skyline notch that is the Merced River Canyon. It's the analog sunset point to that which produces the 'firefall effect' at Horsetail Fall. That photogenic phenomenon happens about 7-8 weeks after Winter Solstice; we are now 7-8 weeks before solstice. The low sunset lets a more colorful sunlight into the Valley at the end of the day. (Horsetail Fall is just trickling now so won't produce the volume of mist/water that catches the light in February.)
In mid-summer the sun sets well to the north of the Merced's exit point, so is high over the canyon rim; in winter it sets high over the canyon wall to the south - in both cases setting when the sunlight is still whiter.
During the day, the sun is traversing a lower angle than in summer, too, but still reaches more of the Valley floor than it does in mid-winter. The Valley's deciduous plants are ending their growing season with the decay of chorophyll that allows other leaf pigments to shine before leaves drop to the ground. Big-leaf maples put on the biggest color display now, and these bands of yellow highlight their preferred wetter, shady habitat in ways that may not have been apparent all summer. The one sugar maple in Old Yosemite Village turned more yellow than red this year, and the afternoon up-canyon breezes have this tree already about 20% bare now. Black oaks are going brown-yellow but many leaves have dropped from some. Dogwoods are still largely green, but showing their startling pink in places. Black cottonwoods are mostly bare now. The brightest plant in the Valley now is dogbane or Indian hemp (Apocynum) - their radiant gold almost hurts one's eyes.
The meadows are a light brown, the fallen pale leaves cover darker ground, more sunshine reaches the ground through branches that are baring. Even ponderosas participate in this season, browning and shedding some of their needles after the dry summer. It all adds up to a lighter albedo. Though the days are shorter and the sun is lower, Yosemite Valley is reflecting more light and is brighter than it is all summer. Only the winter snow will raise the Valley's albedo beyond this dreamy, pale glow of autumn.
Incense cedars are raining their helicopter seeds now. Gray squirrels have been shredding pine cones for a few weeks and their litter of cone scales is everywhere. Been seeing more chickarees than usual in the Valley, also working over the ponderosa cones. Down canyon a bit, Torreya has been dropping its strange green fruits.
The Merced is running at about 80 cfs at Pohono Bridge and dropping since our last storm on 5 October (average for this date is around 33 cfs). Last evening the Valley rim was entirely mantled in a cloud layer that built just at sunset.

Friday, October 14, 2011

Foliage change

Rain ten days ago really swelled the Merced River. The historical average flow for last week was below 30 cfs. It had been running closer to 100 cfs, then leapt to over 600 after the rain. That the high country got snow showed in the nice 24-hour cycle of melt ebb and flow shortly after the storm. Our waterfalls are again looking exceptional for this time of year.
Ladybird beetles are on the move in this warm (moist) weather, with many swarming in El Portal the past couple of days.
A red-shouldered hawk, and a pair of great horned owls were heard in the volunteer campground in Yosemite Valley. A Say's phoebe was seen in Rancheria Flat.
Orion and Canis Major dominate the morning skies if you're out early and have a view to the south.
The sugar maple in old Yosemite Village has just started to show a tiny touch of color. At the Valley elevation, other than dogbane and some bracken, most color has not yet appeared. Alders skip the show and just start dropping their green leaves into the river when they're done, which is now.
Higher up you'll find aspen and bilberry being more colorful now. It should be a good weekend for getting out in the park.
Half Dome cables are down for the winter, Backpackers, Yosemite Creek and Crane Flat Campgrounds are closed for the season now.

Friday, September 23, 2011


Happy, Balanced Equinox.
The Yosemite Facelift is underway and there are hundreds of volunteers deployed all over the park to clean it up. It's a very impressive endeavor, started by Yosemite Climbing Association and successfully grown into a significant success story.
Tony Carlstrom reports observing a California ground squirrel wrestle, subdue and kill a chipmunk atop Sentinel Dome on Tuesday. The chipmunk's body was then dragged off by the squirrel. This kind of gruesome aggression is not something we generally expect from those little snack-beggars. I have observed California ground squirrels feeding on road-killed squirrels in Yosemite Valley.
Rangers at Hodgdon Meadow watched a mountain lion kill a mule deer buck a few days ago. Local bucks are still in velvet but have full grown racks. Lions generally prefer easier prey than large adults males approaching rutting season.
Red columbine still in bloom in the "Ice Cut" on the JMT near Nevada Fall, along with waterfall buttercups.
Afternoon clouds massing from the crest toward the west these past few days.

Tuesday, September 20, 2011

Equinox approach

Autumnal equinox arrives Friday, then it's already October at the end of next week. We had 5 days of afternoon monsoons a week ago, a fun change of season, but summer's heat is not done yet. Mts. Dana and Gibbs were quite snow-covered a week ago; Conness is pictured. Hail had piled up at the 8000' level along Tioga Road. A cloudburst in Yosemite Valley left big puddles that haven't evaporated yet, and lots of runoff debris in small channels everywhere. A torrent coming down the Indian Creek fan went into some NPS houses at the edge of Yosemite Creek. The river gauge shows nice spikes from the series of rainy afternoons.
As it has been for most of the past 9 months, the Merced is running above average: at 129 cfs this morning; the average is 32 cfs for today. Yosemite Falls looks like it does in some Julys; not big, but much more than the usual September dribble.
Lessingia's purple blooms on the Valley floor are even visible from Glacier Point. Bears are still finding ripe apples on trees (lots at McAuley Ranch) but it's a weak mast year for acorns in some spots. Migrating raptors are being seen regularly now. A ring-necked snake was seen near Foresta on the weekend.
Another Half Dome fatality yesterday; this time a climber whose rope broke after he pulled a block onto it. Crowds are absent from the Valley most days, though weekends are still relatively busy. Our visitors from other countries stand out more now.

Wednesday, August 31, 2011

Shake and Bake

We thought that last Wednesday's little earthquake here was exciting, then we had the Motor Fire come to El Portal on Thursday. The fire started on the highway, on the south side of the Merced River, jumped across to the north and quickly shot to the canyon rim. It moved east toward Incline and El Portal, but a heavy application of brute force firefighting in steep terrain (including use of the mighty DC-10 Supertanker) has contained this in a few days.
Now outside the Conservancy office in El Portal there is fresh handline, just a hint of smoke, and no helicopter traffic. Ground squirrels bark, acorn woodpeckers laugh their maniacal cackles, scrub jays squawk. A tanager was 'br-dip'-ing earlier, and a phoebe 'p-chew'-ing. Grindelia remains in bloom in El Portal and the pale turkey mullein is having a good year. The river is more refreshing than ever as canyon temperatures will remain near 100 for the week.
The Motor Fire is nearly out, but the Avalanche Fire near Badger Pass continues to smolder. Though the park was open and not too smoky, visitation plummeted during the Motor Fire excitement; people may have misunderstood the location/impact of the blaze. Maybe it'll be a somewhat quieter holiday weekend.

Thursday, August 25, 2011

Founders Day

The National Park Service was established on this date in 1916, and today's Director is announcing big plans to prepare for celebrating the centennial in 5 years. In Yosemite we are also planning diverse ways to observe the sesquicentennial of the Yosemite Grant in 2014. This was when the US government protected Mariposa Grove and Yosemite Valley (yes, 8 years before Yellowstone).
There was yet another regretable fatality in the park early this week, when a hiker fell from the top of Half Dome, down the face. No official story for how this happened has been released.
Some of us woke to an earthquake yesterday (24 August). After anomalous quakes in the prairie of southern Colorado then near Washington, D.C. in recent days, it was a little more exciting to hear the ground roar then feel it tremble for a moment here. Our event was from a 4.2 shaker, over near Mammoth Lakes on the East Side at 5 a.m. The hypocenter was 10 km beneath the Sierra, between the crest and Mt. Morrison.
The Merced River is low, but not as low as it usually is at the end of August. Yosemite Falls is still relatively impressive - far more people are taking photographs of it than ever do in typical August. Squirrels are shredding ponderosa cones. Bears are finding ripening apples, and though the eat pounds of them, their scat appears to leave a lot of calories untouched.

Wednesday, August 10, 2011

Smoke and Heat

The Avalanche Fire is putting up a good amount of smoke from just above the western end of the Glacier Point Road and it finally feels like summer in the Sierra. This fire was caused by lightning and is just over 400 acres. It's burning at ground level in a healthy way and managers hope it'll burn at least 2000 acres.
The river and waterfalls are still running at unusually high levels, approximately 4-5 times the trickling volumes normally seen in early August. Yosemite Falls is still worth a photograph and Vernal is still all the way across the lip, and putting lots of mist on to the Mist Trail.
Birdlife has quieted considerably in Yosemite Valley. Orioles and grosbeaks are still around, but they are silent. Mule deer bucks have full, velvety racks now.
Coneflower, some tincture plant, lotus and milkweed are in bloom in the Valley - it's a great year for floral displays. The show has shifted to higher elevations where pentstemon, gentians and others are blossoming. Post-bloom, our native raspberries are ready for harvest in the Valley. Yum!

Thursday, July 14, 2011

Summer Still Coming

Blazing stars and Clarkia are still in bloom in El Portal, buckeye flowers are gone and leaves are browning. Yosemite Valley has spicebush, cow parsnip, Draperia, Gray's lupine and azalea in bloom. Birds have gotten quiet, ducklings and merglets are nearly full grown. The Merced River is still running at 400% of normal flow for mid-July, but the top of Table Rock is partly above water and the Valley has been opened to rafting/floating.
Utilities challenges persist in Tuolumne Meadows, but NPS hopes to activate the septic and water systems tomorrow. If they work this means that employees can move in up there and that facilities can open up. The campground is supposed to open Friday night, the Visitor Center should open Saturday and the Tuolumne Meadows Lodge plans to open on Monday the 18th. It'll be a short season, with many facilities starting to shut down after Labor Day, in just 7-8 weeks.
Flowers are pretty good at the 7-8000' level now, with bright Sierra pride pentstemon lighting up the roadcuts. Lots of snow and high water persist along Tuolumne trails. Hikers should plan on covering fewer miles than on dry ground. The waterfalls in the Valley are still quite impressive.

Sunday, June 19, 2011

June Skiing

Tioga Road has opened, but summer has not really arrived in the park's high country yet. Tuolumne Meadows is a lake, Tenaya Lake is mostly iced over (with renewed freezing and new ice last night), snow covers a good portion of the terrain above 6000' (north-facing slopes are mostly snow) and meltwater is filling every trail. Skiers still have time to enjoy the slopes near Ellery Lake, False White, Mt. Conness, Mt. Hoffmann, Mt. Dana and more. Backpackers are going to struggle for a while to find trails, to make distance over snow, to avoid wet feet in all the runoff. No facilities are yet open along the Tioga corridor, including TPR, Saddlebag Lake road, White Wolf or anything in Tuolumne Meadows.
Half Dome cables go up this week for those with permits. Walked the west valley loop on Saturday; flowers are looking good: iris in El Cap and Bridalveil Meadows, yellow violets, white Nemophila, Arnica, Senecio, Alumroot, thimbleberry, Linanthus, larkspur near the base of Bridalveil Fall, creek dogwood, Azalea (smells SO good), globe gilia, blue dicks, golden brodeia, silverleaf lotus, Indian paintbrush, pussypaws, catchfly, and more. We saw no snowplants on the loop. One sow bear with two cubs near El Cap's Nose. Slackliners working their art over the icy Merced at El Cap Bridge. Ribbon Creek is running very high in several channels. Birdsong is still plenty active: grosbeak, tanager, Wilsons and yellow warbler, Cassins and warbling vireo, creeper, song sparrow, spotted towhee, etc.
Hotter days are coming this week and the river may hit another peak above flood stage. It is unusual to have such a late peak, such a high peak, and for the river to hover close to the flood level for two weeks like this. What next in this atypical spring/summer transition?

Wednesday, June 15, 2011

High Water is Here

The river gauge at Pohono Bridge is just about tapping the formal 'flood' stage this morning, at 6300 cfs, or a hair under the 10' mark. This is a little lower than the forecasted overnight peak. Tonight's projection is to go over 11' or perhaps 9000 cfs. If it gets that high, the river will be up on parts of Valley roads, not to mention flowing into two campgrounds and Housekeeping Camp. Rangers have been preparing for days for this surge of meltwater, to evacuate people ahead of nighttime peaks as needed and to implement area closures for safety.
There have been lots of cyclists enjoying the delight of pedalling on the Tioga Road without cars for the past couple of weeks; no noise but birds, running water and the whisper of gumwalls. There is still snow at Crane Flat, and lots of deep snow higher up. The avalanche zone at Olmsted Point has been a lingering concern, so that part of the road is closed to cyclists and pedestrians. Road/trail crew personnel have been working on that spot and with this week's heat and clear skies, there is a fair bit of buzz about the road opening this weekend. Nothing is official and the high country route may not be safe enough to open until next week.
From Olmsted Point we can see that Tenaya Lake is still frozen over. Today's San Francisco Chronicle has an item about the park's Tenaya Lake Area Plan, in which the Conservancy is involved for funding.
Tenaya's ice is melting quickly, and washing down-canyon to fill Yosemite Valley with its own transient lakes.

Thursday, June 9, 2011

Yosemite Flood Watch

NWS has issued a Flood Watch for our part of the Sierra starting Friday evening. We are getting warmer weather this week and the Merced River has started rising again, reaching 4000 cubic feet per second (cfs) at Pohono Bridge (the west/downstream end of Yosemite Valley) last night. The average annual high water flow for the Pohono gauge is just 2500 cfs.
As has been said elsewhere, on top of our tremendous snowpack, it's been an unusually cool and wet spring. The normal warming (and therefore snowmelt) trajectory has not happened; there is still a huge quantity of snow in our higher elevations. We have just a little less snow now than what we usually have in April; the combination of June heat and April snowpack suggests powerful possibilities. The rate of Merced runoff may get interesting in the next few days.
We had two spikes of just under 5000 cfs in early May. Then we had another cool stretch and on the typical annual highest water date of May 20, the river was running only about 1800 cfs, 72% of average volume.
NBC Nightly News aired a feature last week about Yosemite's big waterfalls during a period when they were running right about average for springtime. The exceptional flows may have already happened, or may be coming within this next week. Though we're now 3 weeks past the usual highest flow date, we may not yet have seen our biggest water volume for the season. In 2010 we topped out at near 8000 cfs; if it stays warm (like June usually does; our forecast continues warming for the next 5 days) we may surpass that and see the Merced back up through Wosky Pond on to Northside Drive.

Saturday, June 4, 2011

Summer Delayed

Our cycle of stormy weather continues with another cool, wet weekend. We had rain and snow over Memorial Day weekend, but that didn't prevent traffic gridlock in the east end of Yosemite Valley. Glacier Point Road was open for a day before more snowfall closed the road again. It's been open this week, but some snow is likely on Sunday, perhaps below 7000' (= another closure seems likely).
Scott's Oriole was added to the park's bird list last week; another new species to add to the white-faced ibis seen a couple months ago. I saw a Lewis' Woodpecker above Foresta on Thursday - one of the 12 woodpecker species (!) in Yosemite records. Some of us feel that we are short on Pacific Slope Flycatchers this spring. The Conservancy's 'Hawks and Owls' course is happening this weekend and there is a lot going on in the raptor world, with peregrine and eagle nests lining the Merced Canyon. There is still space in the casual White Wolf Botany course and the North Dome Moonrise Photography Backpack Trek in July.
It doesn't appear that the Tioga Road will be open in time for the Mono Basin Bird Chautauqua, but the birds will be there anyway.
Thursday night NBC did a program on the park's big waterfall flow , while the falls have actually been running at average or below average volumes for about half of the past month. We had early peaks on 7 and 14 May, which were higher than the average annual peak flow, but were maybe 60% of last year's high water mark. The slow advent of spring warmth may mean no snowmelt 'flood' this year, just a long period of higher water. Or a sudden spike in temperatures could send us a big pulse of meltwater; that's not in the immediate forecast. The waterfalls should still be strong if the royal couple visits Yosemite in July.

Friday, May 20, 2011

Hermit and Porcupine

A bright male hermit warbler was a highlight of yesterday's birdwalk in the Valley. He was in a black oak in the company of several yellow-rumped warblers, a black-throated gray warbler and a Wilson's warbler. We love these springtime collections! Orioles have been silent and invisible this week- did they leave the Valley for lower elevations?
As part of their training on Wednesday park ornithologist Sarah Stock had interpretive rangers out in Ahwahnee Meadow looking at peregrine falcons coming and going from their eyrie up on the Rhombus Wall. She's teaching a terrific "Hawks and Owls" Yosemite Outdoor Adventure program, June 3-5, in the company of great gray owl specialist Joe Medley.
The river and waterfalls are below average volume now but will surely creep back up with a couple warm days here. More clouds come in late Saturday = more waterfalls still flowing in July.
Nearly two feet of new snow fell in the high country this past weekend. NPS road crews have plowed up to Porcupine Summit on Tioga Road. This is beyond Yosemite Creek, before the drop to the long straightaway near Porcupine Flat Campground. It's still many miles and several avalanche zones to Olmsted Point, Tenaya Lake and Tuolumne Meadows. At Glacier Point there's still so much snow it doesn't seem possible to open that area for Memorial Day weekend because water and septic systems won't be on line. It'll be a busy holiday weekend a week from now with all visitors concentrated in Yosemite Valley.

Tuesday, May 17, 2011

Towhee and Frazil

Cold and snow chill Yosemite. We had frazil ice in Yosemite, Sentinel and Ribbon Creeks yesterday morning; a bit late in the season, but not unheard of. The Merced River has dropped just below the average flow rate for mid-May; it has been running at above-average volume since the big storms got started in November. Though average, the falls are still big, but they'll get bigger, and they'll still look good in July. Fire season gets delayed, though the moisture likely means more growth of small fuels like grasses.
A highlight on yesteday's birdwalk was seeing Superintendent Don Neubacher dash out of his office with binoculars in hand to stalk a seldom-seen green-tailed towhee outside the Administration building. He was accompanied by ace ranger-naturalist Karen Amstutz who spotted the unusual bird out her window and had the inspiration to pull the park's boss (a dedicated birder) away from his desk to see the towhee. I'm glad to know that our park is being looked after by such people. My group was surprised to see a second green-tailed towhee a short time later near Yosemite Creek.
Ranger JT reports snowplant emerging near Sentinel Bridge. I've seen a couple in the west end of the Valley, too. Along with new birds and plants, it's exciting to see the seasonal increase in park staffing as more interpretive rangers return to duty or start their first summer as seasonal rangers. Park visitors are lucky to have all these people leading walks and campfire programs, answering questions in the visitor centers, conducting tram tours and cultivating another 24,000+ Junior Rangers.
There is still room in the Yosemite Conservancy's 3-day "White Wolf Botany" course in early July. This is going to be some terrific field time for casual botanists in a special part of the park. We also have space for people to join us for the two "Family Camping Jamborees" in late-July in Tuolumne Meadows.

Friday, May 13, 2011

Warm then Storm

Last weekend's overcast and rain caused the Merced volume (and the tributary waterfalls) to drop back down to near average flow. One might think that rain would raise the river level, but, in fact, the cloud cover and cooler temperatures reduce the snow melting rate much more than a bit of rain can increase the runoff. Warm sun brought the flows up again through the week. Again this weekend we expect a cool storm to bring a bit of rain (and snow -which, of course, reduces the near-term runoff much more than rain does), so the waterfalls will be smaller at the start of next week than they are now.
On most days, the river (and tributary) volume exhibits a nice 24-hour cycle of rise and fall. The hottest part of the day is when the most snow melts up at 7-13,000'; this surge of melt doesn't reach the two Yosemite Valley river gauges until many hours later. It's odd that our highest water flows in the Valley happen after midnight - about 12 hours after the hottest part of the day. That's the lag time for high country runoff to make it down to 4000'.
It was cold enough in the Valley this past Tuesday morning (9 May) for people to observe frazil ice in Yosemite Creek and in Ribbon Creek. A deposit outside the eastern channel at Ribbon Creek persisted into the next day, looking like an anomalous patch of snow.
NPS road crews have reached Glacier Point, and they've reached the White Wolf area on Tioga Road, through average snow depths of 8' and 10' respectively.
The bizarre red snowplant is emerging from the ground in Yosemite Valley. Bracken fern is tall and unfolding its fiddlehead fronds. Dogwoods are fully alight now. Western Wood Pewees arrived this week in the Valley. The concentrations of yellow-rumped warblers and some other birds have dispersed from the Valley to higher elevations a bit. I've been seeing 1-2 bears a week in the Valley, more than has been my usual experience.
If you're up early and have a good eastern view, check out the concentration of planets in the east before dawn.

Monday, May 2, 2011

The burst of spring

I encountered my first Western Tanager of the year on Monday's Conservancy bird walk - just moments after a participant asked about them. It was a stunning, bright male in the black oaks in front of the visitor center - lots of exclamations from all present. Since then, more males have arrived and are singing in Yosemite Valley. This morning we had the triple feature of the bright neo-tropicals when within a short time we also saw the male Black-headed Grosbeak and Bullock's Oriole. Surprises on Monday were the Lark Sparrow feeding on the gravel trail along Cook's Meadow and the Western Kingbird sallying out from the black oak canopy over the meadow. This morning we had a decent look at Vaux's Swifts.
Those black oaks are pale green with dangling flowers now and a few leaves are starting to emerge. The early dogwood below the former diversion dam site, along 140 has 'blooms' almost 3 inches across which are almost fully white. Most Valley dogwoods are still pale green - they're more than a week behind an average spring schedule.
The Merced River has leapt in volume with the warm weather this week; it's doubled in volume in the past five days. This morning it had already exceeded the average springtime peak - and there are still a few weeks of potential increase to the average high flow date. Low-lying Valley trails are starting to get wet, but there's no real flooding yet. (Last year peak flow reached 2.5 times what it is now!)

Friday, April 29, 2011

Wild, Wild Life

Black-headed grosbeaks are now singing in the Valley, there were more orioles on Thursday's birdwalk, and several dozen yellow-rumps encountered in 3 flocks -a tiny portion of them singing. Three Vaux's swifts patrolled over the Valley Visitor Center. Hummingbirds are doing display flights. About a month ago NPS volunteer interpreter Kirsten discovered a rare Virginia Rail near the boardwalk in Cook's Meadow.
On the mammal side, a dark brown bear has been grazing the Ahwahnee Meadow area lately. Two rescue helicopters there on Tuesday night didn't disturb its feeding. Biologists researching our fisher populations are delighted to have encountered a mother with young, moving them from place to place in the south area of the park. Good news for predators and general food web health; bad news for mice and squirrels.
Road crews are grinding away at the extra-deep snow on both Glacier Point and Tioga Roads, slowly making progress to open up the high country for our cars. Tomorrow morning might be cold enough for frazil production, but then it warms up for the early part of the week. There is still a chance for big frazil flows for another few weeks; just because April's over doesn't mean that we won't have some sub-freezing nights in Yosemite Valley.

Monday, April 25, 2011

Slow spring

Too warm for frazil ice, too cool for rapid snowmelt, our recent unsettled weather continues this week with a bit of cloudy damp. The weather forecast leads us to anticipate no frazil ice this week.
Black oak leaves are not quite starting to burst out of buds yet, though they have lower down. Cottonwood flowers are out along the river. Insectivorous orioles are in the Valley now, ahead of most insect food. Redwings are singing in Cook's Meadow, mallards swim in pairs, yellow-rumped warblers sing a bit on sunny days.
Former Yosemite employee Paul Keel, back for a visit, added a new species to the park's birdlist: our first ever white-faced ibis. Paul is a state park ranger now, down on the coast, and he got good photos of the ibis in El Capitan Meadow. You never know what you'll come across, if you're paying attention.
This morning we watched a male belted kingfisher working the oxbow lake in Cook's Meadow. Fun to see a fish predator well away from the river channel.
More predators will be on display in the Conservancy's "Hawks and Owls" field seminar the first weekend of June. Park ornithologist Sarah Stock and great grey owl specialist Joe Medley (yes, the son of Steve Medley) are the two instructors. We are delighted to have these two knowledgeable experts (and charming individuals) teaching this fun program. There's still space available; free camping and free park entry are part of the package. Raptors rule the skies...

Wednesday, April 20, 2011

National Parks Week

I am back in Yosemite after two weeks away, and what changes there are. The free entrance to Yosemite for National Parks Week, combined with some school spring breaks has meant a busy week in the park. The natural scene is busy, too.
Snow is gone from the Valley floor except in a few shady spots. Waterfalls are bigger than average, with the recent warmth getting a start on melting off our exceptional snowpack. Cooks, Leidig, El Capitan, Stoneman, Ahwahnee and Slaughterhouse (lovely, I know) Meadows all have standing and/or running water in them now; some paths are blocked, but none of the main ones yet. Table Rock, our local visual river gauge for Valley commuters, is underwater.
Frazil ice forecast for this weekend: POOR.
Yellow-rumped warblers are at their brightest in the black oak canopies, where tiny pink leaves are barely starting to emerge in the Valley. Black-throated gray warblers are doing their excited, buzzy call in the live oaks in the Valley now, too. A great gray owl was reported on its nest up near Crane Flat, though there's so much snow there still, their food is out of reach and it's hard to imagine successful breeding at this point.
Our "Moonbow Photography" Outdoor Adventures course was a success on Sunday night, with a bright bow visible for a couple hours in-between overcast periods. Next up is Ken Rockwell and Dave Wyman's "Spring Light Photography" course, and then an excellent "Hawks and Owls" program the first weekend of June.
Our regular public birdwalk will be seeking John Muir's favorite bird tomorrow, Cinclus mexicanus. Thursday is his 173rd birthday. Friday is Earth's birthday; stand up for what you stand on, as they say.

Friday, April 1, 2011

Yosemite Recovered

The storm of 20-21 March goes into the record books as one of the most significant in decades: over 12 feet of snow at the 7-8000' level, and 9 inches of heavy snow that broke down thousands of live oaks and other trees at the 2000' level. Electricity was restored after 6 days, and visitation has now picked up.
We've had very warm weather the past few days. Bird activity has increased, flowers are on the rebound, and the Merced River has doubled in volume and is really turbid. The river has gone over 1500 cfs at Pohono Bridge, more than twice the average flow for this date. Sierra-wide snow surveys show 165% of normal water content in the snowpack; our local results come out shortly and will surely be comparably abundant.
We all look ahead to the waterfall season of the next 3 months, hoping that all this snow runs off over a long span of summer, rather than all at once. Photographers Ken Rockwell and Dave Wyman have timed their "Spring Light Photography" course to coincide with predicted high volume, 19-22 May.
We're also coming into peak frazil season this month. The frazil ice forecast is poor for the next few days, as temperatures are mild. But the warmth makes more mist, which will produce more frazil particles when the temperature does drop again.
I'll be away from the park the next two weeks.

Saturday, March 26, 2011

Yosemite Recovers

Electricity is supposed to be restored to El Portal and Yosemite Valley today (Saturday). Most park roads are now open, though with chain restrictions on all of them. Highway 140 is closed between Mariposa and El Portal by a rockslide near Briceburg; it should be open by Monday or sooner. Badger Pass is closed, but hopes to open for its last weekend of the season, April 1-3. There is over 14 feet of NEW snow at Badger!
The Valley floor has 1- 1.5 feet on it. DNC is using these rare conditions to lead springtime snowshoe walks from the Ahwahnee this weekend. The Visitor Center is fully staffed, and a few visitors are trickling through. It's snowing in the Valley now, but snow isn't sticking much below the 3500' level. Though Hwy. 41 is open, buses are being turned away from the south entrance at the moment. You MUST call 209/372-0200 to check on road conditions before heading to the park.
The Conservancy's annual Spring Forum was supposed to be held today, but conditions obviate that possibility; we'll try again next year. Tomorrow's wildflower field seminar in El Portal is also cancelled; Michael Ross is teaching two other botany courses in the summer where we hope snow won't be a factor.
Warm weather returns to the Sierra next week, with sunny and low 60's in Yosemite Valley. We should see a big spike in runoff by late in the week, with lots of wet meadows, though we probably won't really approach flood level. It's going to be a terrific season for Yosemite waterfalls.

Tuesday, March 22, 2011

Yosemite Closure

An unusually cold and wet storm has delivered a lot of snow, causing extensive tree damage in Yosemite. All roads into Yosemite are closed. Power is expected to be out for 5-7 days. At under 2000' El Portal got 8-9 inches of snow, something not seen in decades. Most of the damage is to live oaks, with hundreds of trees and large limbs down in El Portal alone. The rest of the Merced Canyon has numerous small rockfalls and landslips partly blocking roads between Mariposa and Yosemite Valley. The snowfall took place mostly overnight on Sunday. Skiers exiting Ostrander Hut on Sunday worked as a 20-person team to break trail. They scooped up others along the Glacier Point Road who had dropped from exhaustion pushing against the heavy accumulation. When they reached the trailhead, they couldn't leave Badger Pass; about 60 people spent the night in the day lodge at Badger. Yosemite West has run out of water and all residents and guests have been escorted out of the park. Community meetings later today will tell us more, but it's possible that the park will be closed and all remaining visitors and non-essential employees evacuated. The generators that keep the lights and heat working can only do so much, and they're needed to operate water and wastewater systems, too.
I'll post more when I can.

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.

Monday, March 14, 2011

The Wearing o' the Green

A lot of the recent snow is now gone from the floor of Yosemite Valley and run-off is picking up. The Merced River is now running at about twice its average volume for mid-March. We got a bit of rain last night and we expect more rain/snow off and on this week. It'll be a grand year for waterfalls with so much wet snowpack in our upper watersheds. Next weekend may also be stormy, with the snow level at or below Yosemite Valley. Frazil ice forecast: low-moderate probability for next weekend.
Meanwhile the foothills and Merced Canyon west of Yosemite are greener and greener with buckeye leaves still emerging. Redbuds are pinking, getting ready for their startling color show soon. Popcorn flower dominates at ground cover level, poppies are coming along, false goldfields and fiddlenecks are looking good. The Hites Cove Trail is well worth a stroll now - yes, even if it's on a rainy weekend; you'll see more newts and hear more chorus frogs singing love songs.
The Ahwahnee re-opens on Thursday, in time for St. Patrick's Day. Meanwhile, we send seismic sympathies to the people of Japan for the blow that the restless earth has dealt there.

Tuesday, March 8, 2011

Quake Noted

A foothill earthquake was heard, not felt, by employee-residents in El Portal shortly before 11 p.m. last night. The hypocenter was nearly 15 miles beneath the Bootjack-Darrah Road-Triangle Road area, west of the park toward Mariposa. This is down in the granite batholith that underlies the western metamorphic belt we see at the surface along much of Highway 49 south of Mariposa. Hearing the earthquake in Rancheria Flat may be helped by its location at the contact zone of the granite and the older metamorphic rock.
The river has been well above average for months now, and the weekend rain has brought the river up again. It was very turbid yesterday. Yosemite Valley got rain and now the snow cover is patchy. The average flow for the Valley's exit in early March is about 300 cfs; it's now running over 500 cfs.
El Portal's flowers are looking good with numerous species found in many sunny locations. Bird activity has picked up, with abundant noisy robins joining vocal titmice, Hutton's vireos, flickers, both towhees and more. Treefrogs are chorusing in various places, even in snowy terrain in the Valley and Foresta.
The summertime's Scorpio is high in the south before dawn. The ISS flies across our sky about 7:30 this evening; STS Discovery has de-coupled for the last time before returning to solid ground tomorrow.

Tuesday, March 1, 2011

Winter is Back

A more usual sequence of wintery storms has returned to the Sierra after so many weeks of dry, mild weather. Wildflowers in the lower Merced Canyon have had to endure extra-frosty mornings and a few doses of snow, even down to 2000.' Today we're in-between snows, with warm-ish, sunny conditions. A few inches of snow still cover the Valley floor, but creeks will come up as the sun converts the snow coverage to run-off. More snow and rain arrive tonight. We expect another set of high elevation snow survey data soon.
Frazil ice continues to appear in Valley locations, with our above average run-off and cold overnight lows. We don't generally see it this early in the season, but this year is different. Maybe its abundant apparitions are a result of the popularity of the video. As April draws closer, we may try to post frazil forecasts here. These can only work 2-3 days ahead, when we get good temperature forecasts from NWS.
Yosemite has come to life indoors, in the form of the Yosemite Renaissance art exhibit in the Museum Gallery, next to the Valley Visitor Center. There were 578 entries submitted, and just the best 42 qualified to be displayed for our enjoyment. Come see the varied pieces between now and early May; pretty inspiring.

Sunday, February 20, 2011

Same price, now with extra waterfalls

This week's return to winter conditions has been a nice break from weeks of sunny, pleasant, mild weather. Skiers are happy (when the road to Badger Pass isn't closed) and waterfall enthusiasts should be, too. The snowline dipped below 2000' twice, and left snow in El Portal. More rain fell at low elevations, and all the small tributaries of the Merced filled with runoff.
The 140 corridor between El Portal and Briceburg has been dynamic in the past few days: lots of cascades pouring down to the highway, a couple of landslips, and still more flowers. It's not too early to go enjoy the Hite's Cove trail for living color. The highway is lined with sparse fiddlenecks in sunny spots. On sunny slopes across the river, patches of poppies and false goldfields are evident. Right now the waterfall buttercups are at their peak above the road, immediately downstream of Ned's Gulch - a lush display is found on the drippy metamorphic substrate.
A red-shouldered hawk was seen at Rancheria Flat today, joining the non-wintery black phoebes and Anna's hummingbirds that have weathered the snowfall. Treefrogs are chorusing in wet places.

Monday, February 14, 2011

Sunday 'Firefall,' Monday Snowfall

We had a marvelous show at Horsetail Fall last evening, with a cloud layer to the west shading the East Buttress of El Capitan until just the right moment. Red sun suddenly came through and turned a gray cliff into a highway flare for the last 5 minutes before sunset. Some folks left early, thinking that the 'firefall' effect was altogether obscured by the clouds. Whoops of excitement arose from the dozens of hopeful fans along Northside Drive - it was like a bottom of the 9th grand slam that takes a losing team into victory; it ain't over til the sun has actually set beyond the Coast Range (around 5:40 now). As with our other waterfalls Horsetail Fall has had above average flow in it lately (it's keeping Woski Pond full); last night the wind made it look like less water, but it carried the red mist well aloft of the wall.
Much of this week looks less promising for observing Horsetail aflame, but we're excited to have another potential 2 feet of snow on the way to soften the mature hardpack that's tough to ski on. Stormy weather has made an initial appearance in Yosemite today and should taper off toward next weekend. We have good reason to hope that our photography course on Friday/Saturday stands a fair chance to get good Horsetail light. If high water persists, there's even a chance for a rare February moonbow next weekend.

Friday, February 11, 2011

More earth

The latest snow surveys show that the Merced watershed courses snowpack has 142% of average water content. Runoff in the Merced and its tributaries is still well above average flow for early February; all the waterfalls are looking robust.
This high flow combined with cold nights to give us frazil ice in Yosemite Creek on Monday and Tuesday nights (and probably others). This is earlier than usual, but not unprecedented. We know that California temperatures have risen by 1.5 degrees C since 1880; there must've been much more frazil through the season back in Muir's day. That may be one reason he abandoned his cabin along Yosemite Creek and moved into his 'hang-nest' up high on the eaves of Hutching's sawmill.
You saw Steve's frazil ice video in the Yosemite Nature Notes series (which is funded by Yosemite Conservancy). He's out with his camera each evening right now working on a 'firefall' film. Watch for that one soon, or come up to the park in the next 2-3 weeks and take your chances on seeing the shining glow of Horsetail Fall at sunset yourself. Get out with a pro photographer in next weekend's Outdoor Adventure course for an improved chance of capturing this phenomenon for yourself before you see Steve's version on-line.

Monday, February 7, 2011

Frazil Ice Planned for April

The NPS/YC Yosemite Nature Notes video on frazil ice has gotten remarkable viral traction on-line. We've received lots of messages lately about where/when people can see the stuff. As it says in the film, April is the best month for observing the ice flow in progress, but you have to either be lucky with timing, or come stay for the whole month so that you can go out before 8 every morning to see if it's there. If the night's temperature is well below freezing, you should see it. It doesn't generally happen in mid-winter because the water volume in the falls is too low to generate enough mist to form a lot of ice. (Though the conditions were right this year to form frazil in Bridalveil Creek in late December.) There's a decent likelihood that April visitors will at least see the remnant deposits of ice, which just look like snow lining the creek banks.
An earthquake near 1 a.m. Sunday morning was noted by some park locals, who heard it as much as felt it. It was a 2.2 magnitude, centered 14 km beneath the headwaters of the South Fork Merced River. The Clark Range has had a light series of small, deep quakes like this one over the past five years; this fits in with that movement under the batholith.
In more earth news, the Yosemite Conservancy has an Outdoor Adventure course February 18-19 seeking to photograph the elusive (almost mythical) 'firefall' effect that happens in Yosemite Valley for a couple weeks each year. Pro photographer John Senser has captured this transient phenomenon many times over the years and will be your best guide to find this glorious spectacle. Call Carolyn to sign up: 209/379-2646, extension 10.

Monday, January 31, 2011

Long Live Doug Hubbard

Doug Hubbard passed away in Texas recently, at the age of 92. He worked in Yosemite from 1952 to 1966, mostly as the park's Chief Naturalist. Among other things, Doug is the guy we can credit with creating the Pioneer Yosemite History Center (and those stagecoach rides) in Wawona, establishing the Nature Center at Happy Isles , writing the guidebook to the Yosemite Cemetery, and initiating the work of Julia Parker and others in demonstrating Indian cultural practices. He got the old train station from Bagby (and other rail history elements) moved upriver to El Portal, where it serves as the Yosemite Conservancy's office (where I write these words) today. We are lucky to have had forward thinkers like Doug working for us all those years ago.

Bit of rain and snow over the weekend, with the Valley getting a few inches of new coverage. Badger Pass reports 8 inches of new. El Portal has more and more flowers: above Rancheria Flat are found less than a handful of poppies, fiddlenecks, popcorn flower and peppergrass in bloom. Waterfall buttercups are blossoming profusely in the shady wet spots they prefer along the lower canyon. Elderberry and buckeye are starting to leaf out.

Saturday, January 29, 2011

Flowers of January

Seen while strolling El Portal yesterday:
Stellaria -starwort
Lamia-dead nettle
Plagiobothyrs-popcorn flower
Claytonia-miner's lettuce
Capsella-shepherd's purse
Erodium-crane's bill
All of these species were flowers in bloom - not many, but nonetheless, mountain wildflowers (four non-native) blossoming in January. Other locals report that the Hite's Cove trail now has small numbers of shooting-stars, western rue anemone and poppies in flower. (The photo is not today's, but what's to come.) Snow and rain tomorrow will keep most flowers to a more normal schedule.

Wednesday, January 26, 2011

January Thaw

Dry mild weather continues for another week; expecting low 70's in El Portal today. There's still a heavy snowpack above 7000', but more bare ground is showing below that, depending on aspect, etc. Ephemeral streams Sentinel, Eagle, Horsetail and Ribbon Creek are all still flowing into the river -unusual for January, for weeks on end, and with 90% snow cover persisting on the Valley floor.
Alder catkins are releasing pollen. Some locals suffer allergies in some Januaries; could be alder, incense cedar, or maybe fine micaceous dust kicked up off of the sanded roadways.
Foresta is snow free and friends took a walk down the dirt road last weekend. Found Lawrence's goldfinches at McAuley Ranch and lots of water in Crane Creek (shown).
Stellaria is blooming in El Portal - a good genus name for non-native Common Starwort. (No relation to GW Steller of the jay, of course; different spellings.) Lamia and native Fiddlenecks will show a few blossoms any day now, if you can believe that. In other stellar news: if you're out before 6:30 a.m. and aren't deep in a chasm such as confines the Merced River, you'll see that the Summer Triangle is already clearing the eastern horizon before dawn and Scorpio crawls into the sky just like a July evening.
This Friday marks 25 years since the Challenger accident. Watch the skies.

Wednesday, January 12, 2011

Turtleback Dome

Noel and I trudged through deep snow up to where two of our webcams are located and repositioned the east-facing camera from where recent winds had pushed it. A couple of weeks ago, during the latest of big rain/snow storms, there was a one-hour period when the wind averaged about 17 mph. Within this spell there were surely gusts that were in the mid-30's and perhaps as much as 50 mph, though the instrumentation here doesn't record that data. At least one of these gusts swiveled the camera to the north, giving a view of the forested slopes at the west end of the Valley. Now you can see El Cap and Half Dome again.
We had a few hours of light rain yesterday afternoon/evening but today was mostly clear and fairly mild. Badger Pass reports over 100" of snowpack.
All of the 2011 Outdoor Adventures programs are posted in our webstore now, and they'll be in the 'Experience Yosemite' part of our website soon. Think about one of these programs as a good, new reason to get to the park.
This coming weekend all national parks will observe Martin Luther King, Jr. Day by waiving entrance fees. The 15th-17th will all be free days to enter Yosemite. Now's a time to come see our popular park in the off-season, maybe to see it in a different way. Differences can be good things. Use your saved $20 in some generous way.

Thursday, January 6, 2011

Ice, Ice

Yosemite Valley is quite frosty this week. Last week's storms left shin-deep snow on the Valley floor and it's persisting nicely. The snow is off the trees on the sunny north side of the Valley, but the shady side remains all white, top to bottom. Surface hoar is building in all the shade zone -endlessly pretty stuff.
At the same time that not much snow is melting, there's still a good amount of run-off from side streams. Horsetail, Ribbon, and Eagle Creek all are flowing on the surface into the river. Wosky Pond is full.
Ravens and steller's jays are active, as usual. A coyote has been begging at the intersection of 140 and the Big Oak Flat Road (the diversion dam, for those who remember that feature from 1917-2003).
Venus reaches its greatest western elongation this weekend, which means that if you're up early in the morning, it's high in the sky and you'll see it for a long time before the sun comes up. If you mark its general position relative to the sun, you can actually see Venus shining in the bright blue sky all day. At a maximum elongation (greatest angular distance from the sun in our sky) it's easier to see than when it's close to the sun.
Another bright point for Yosemite fans is the reappearance of the cult classic Yosemite Marching Band video on the web after over a year of absence. If you appreciate elaborate absurd humor, give it a look at:

Saturday, January 1, 2011

La Nina Settles In

It's been a pretty dynamic start to our Sierra winter with frequent storms and plentiful snow and rain. Sierra-wide, precipitation is reportedly twice normal. For New Year's Day the park got some snow down below the 4000' mark though that's lifted in the afternoon.
Highway 140 was closed by a rockslide just above Parkline on Thursday morning, but NPS road crews did some blasting and re-opened the road last evening. The recent cold/wet weather has brought a lot of rocks down here and there.
Down canyon at Clearinghouse, there's a bank of yellow mustard (Sinapis) in bloom. This is the green season below 3000' here, and the El Portal area is lush with the new foliage of lupine, poppies, etc. ready to add color in a couple more months. We'll be looking for waterfall buttercups within the next few weeks, as well as skiing on a deep snowpack above 6000.'