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BACKPACKER ALERT: April 1, 2017. PCT High Sierra Spring Threats on Full Display

Alex Wierbinski's picture

By Alex Wierbinski - Posted on 01 April 2017

April 19

This Alert will be in effect as long as this massive snowpack sits upon the Crest. That is uncertain, but will likely last through at least the middle of July, depending on weather. Good chance for this snowpack to see next season's Winter.

4-20 Weather Status Update

April 19 Weather Status Update

See updates through comments below, and the 2017 High Sierra Backpacker's Calendar.


 April 20

Snowpack officially Vast:

April 20 reading puts state average near 200%
(See Calendar)





April 1, 2017
The most important topic of this date is the massive snowpack on the Sierra Crest and the extreme danger it poses to PCT hikers. The dangers of High Altitude Snow Travel will soon be supplemented by very dangerous fording conditions when this snowpack begins to thaw.

These conditions require skills, gear, and fitness to assure any level of safe travel as of this date. Undercutting and safety along the banks of creeks emerging from snow cover is currently increasing, as will the difficulty of travel conditions increase as the pack softens under the increasing heat of Spring.

Extremely difficult travel conditions will soon shift from hard snow that defies traction to wet snow offering no foundation. We will shortly transition from barely clinging to the mountain-side to sinking up to our waists with each step. As Spring progresses cold mornings will bring the former condition, warm afternoons the latter.

The same temp shift driving the changing character of the snow pack will soon drive even the highest river fords to levels unsafe for fording, and make the major rivers raging torrents of destruction. These temp shifts change the character of the Sierra.

The snowpack itself will become sopping wet, saturating anything and anyone in contact with it. These are the times that hikers without sufficient insulation can find cold combining with exhaustion to degrade decision making as well as technical execution & style to create very dangerous situations. I see Wet, cold, and tired PCT hikers surrounded by a sea of deep, wet, energy-sucking snow divided by an endless series of raging torrents of typically tiny High Sierra creeks surging like rivers, each supercharged by Spring's mighty flows.

The trails will be flowing like creeks, when we get down to them. And they will lead to the mighty rivers, which will be downright scary, once this massive snow pack begins to melt in earnest.


On March 25th Cayenne added her observations about this Spring,

"I just checked their site (PCT) and no mention or discussion about the fact that the PCT will not be 100% open this summer. Mammoth, last summer was a shit show of backpackers between the PCT and the JMT. People are planning their trips now with no clue and all “positive vibes & intentions”.

For example, during the 2011 (heavy snow) summer we planned to camp in the meadow (Tuolumne) and ended up camping in Lundy Canyon instead. Did the hike up to Lundy Falls in ankle deep water, the trail was a creek. That is what I expect for this year in the Sierra’s.
I did not even go into how many down trees, eroded trails and washed out bridges will be encountered. Not a good year for the novice backpacker or hiker. Can anybody say, “backcountry glissading accident or swift water rescue?”

Dude, we had 180 mile ridge gust out here – INSANE!!! The cornices on some of the high altitude passes will not melt out on the north facing aspects this summer. NOAA is calling for over a foot of snow this weekend. The high country just keeps getting hit.

I am happy the drought is over and the CA & NV water table will be refreshed. I hate fording rushing creeks in waist deep water and big rivers freak me out.

I honestly think that very few people will complete the PCT this year because the Cascades have had an amazing amount of snow too. Crater Lake, Mt. Bachelor, Mt. Hood and Mt. Baker are all having record snow years too. We lived up there from 2000 – 2006 and drifts take a long time to melt out up there in record snow years.

I will do my best to keep people informed as “The Great 2017 Thaw” begins!


Me too!

Take Care and Bee Safe


Happy Trails,



Spring Thaw Conditions

Calendared Status with Reporting Resources

Week of April 9 to 15

Week of April 16 to 22

Week of April 23 to 22


Latest News/Status

Latest (April 1) Snow Course Measurement

All Snow & Thaw info on Weather Page



All Snow Reporting Stations and Watersheds

All River Flow Data, Forecasts, & Warnings


PCT Hiker Snow Accident & Conditions Report,
Whiteblaze, March 24, 2017.

High Sierra Mountain Safety: Wrecks & Rescues


Latest News


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Alex Wierbinski's picture

Snowpack officially Vast:

April 20 reading puts state average near 200%,

Alex Wierbinski
Alex Wierbinski's picture

REPORT Kennedy Meadows Pack Station

Report from Matt Bloom of Kennedy Meadows Pack Station.

"PCT hikers in the snow for a long ways & time this year."

"KM will be Opening for Trout Season on APRIL 28, come on up."

Sonora Pass: "It looks like Sonora Pass will open between Memorial Day Weekend and Mid-June, is my guess right now, but this depends on weather."

This will be a slow Summer in the mountains and a short season for the High Country."

Make your time count!

Alex Wierbinski
Alex Wierbinski's picture
April 19th

Note the pattern of a series of Highs & Lows I mentioned on the 15th has sustained itself through the 19th, & looks likely to contain one more wet pulse.

Look at the pattern of that week swinging from Storm to Cold warning and back to Storm again as each pulse of High and Low pressure came across during the week of April 9-15:

From the 6th to the 20th we've seen a remarkable pattern composed of a rapid series of Wet, Warm frontal-Lows followed by brief clear, cold Highs. Rapidly. This current cool High is giving way to another frontal Low, & it will warm into the 20th with that moisture as this pattern then breaks, followed by cooling with the clearing-High building from 21st to 24th.

Then, after the 21st some heat will build in under a more persistent High, unless this series of Highs-Lows come back...

This means a nice window may well be opening up for some deep-snow High Sierra Snow Trips this weekend and next week.

Maybe. This is classic Spring Instability. Keep your eyes open, and on the skies! The weather plays the tune and sets the timing the snow melts by.

Alex Wierbinski
Alex Wierbinski's picture

This snow travel hazard was quickly compounded by mountain storm warnings from the sixth to today, the eighth. The decay of this storm is opening some clear skies and the potential for a COLD HAZARD CONDITION this evening, the eighth of April.

This cool little High forming over us now appears to be followed by a mass of tropical moisture moving our way. It appears that the period of low precip stability we experienced during the month of March and beginning of April is over.

The question is how it will heat up, for heat up it will. Will it heat up rapidly, lashed by continuous tropical storms? Or will it heat up slowly under diminishing cold snows?

That question determines a whole lot more than just the fate of our backpacking season. The short term answer this year determines the stresses the whole California Water System will face this year. The very viability of California's water system and the vast population it supports, and maybe even the fate of Mankind hangs in the long term answer to this same question.

Alex Wierbinski
Alex Wierbinski's picture

Peter checks in on April One after retiring the Lake of the Sky Outfitters in South Lake Tahoe. Peter brings the wise observation that the skeeter populations are going to be huge and likely fed by moisture all Summer long.

Alex Wierbinski
Alex Wierbinski's picture

Marty Maine, Senior Trail Crew Mechanic, reported on April 1 that numerous hikers are starting out too early for their skill sets.

Marty reports that 3600 PCT permits were issued, and both he and Cayenne below are concerned not just about safety issues of hikers unprepared for extreme snow and fording conditions, but also about congestion on trail and especially at resupply spots as countless disappointed PCT hikers are driven off the trail.

Marty and others concerned in & with backpacking the Sierra have been heading South this Spring to bring good scouting information to potentially thousands of minally or under-informed and under-geared PCT hikers who are currently hiking North.

This is not an "ultralight" Spring in any sense of the word!

Alex Wierbinski

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