Home > Trip Reports > Nov 7, 2018, Camp Muir AVALANCHE Red Flags Ignored

Nov 7, 2018, Camp Muir AVALANCHE Red Flags Ignored

11/7/18
WA Cascades West Slopes South (Mt Rainier)
7070
13
Posted by Amar Andalkar on 11/10/18 11:20am
November 7, 2018, Mount Rainier, Muir Snowfield and Camp Muir:
Very Unusual Natural Avalanche at 10300 ft, Major Red Flags Ignored by Skiers in AAA Gully!!??


Question: If you saw this large natural avalanche crown (about 2-4 ft tall and 300 ft wide) on a slope near 10300 ft on Mount Rainier with a large debris pile below it, would you ski the broad open gully beside it which shares the same slope angle and aspect?? On the first sunny day after the storm and winds which created the slab that slid!! Especially if you could see evidence of a hard water ice layer almost everywhere beneath the most recent snow, including all over the place at 10100 ft Camp Muir!!


Avalanche crown visible to the left of Camp Muir while skinning up the Muir Snowfield near 9500 ft, with AAA Gully at right center. The crown was also visible all the way from the Paradise parking lot, if you happened to look closely or took a highly zoomed photo. Note the continuing high winds on the upper mountain, building more wind slabs for the unwary!

I can only hope and wish that everyone who backcountry skis or snowboards would answer a resounding "NO" to this question -- but I know that's far too optimistic. One thing that's certain though, is that those who would answer "YES" are very likely headed for a major avalanche incident, and probably sooner rather than later. This is no joke, folks. Read on for a more detailed explanation of the circumstances behind this very unusual natural avalanche, and what would appear to be a very lucky escape for 2 skiers/snowboarders.

Note that additional public comments on this topic can be found in my post on the TAY Facebook page:
https://www.facebook.com/groups/turnsallyear/permalink/10156773653829699/




Morning panorama from the sun-warmed Paradise parking lot. (click for triple-size version)


Headed up from Paradise on a lovely Wednesday morning, the first sunny day at Paradise in 2 weeks since the lengthy mid-October high pressure ended and a series of fairly wet storm systems moved into the Pacific Northwest. So nice to be easily skinning right from the parking lot despite only 8-12" of snowdepth there, rapidly increasing to 2-3 ft a bit higher up. I had almost not come out this day given that I had been fighting a moderately severe cough / cold since Sunday, but woke up feeling semi-OK in the morning, and decided to give it a shot even though I wasn't close to 100% health.


Morning panorama from about 6200 ft below Panorama Point (at center). (click for triple-size version)


Everything seemed about normal for early season ski trips on Rainier, looking very familiar indeed (except for much more snow), especially since I had skied from Camp Muir 9 times already since September 17. A firm base from recent snowfalls, compacted several times by intervening heavy rains, was very nicely burying most of the rocks already. And all topped by 8-12" of new medium density powder, just outstanding skinning (and later skiing) conditions.


Panorama of the skintrack ascending beautiful smooth powder from about 7500 ft near the bottom of Muir Snowfield. (click for triple-size version)


One unusual and unfamiliar thing was just barely visible though, almost the whole time while skinning up: far away and above on the steep slope just to the left of Camp Muir, there appeared to be a large avalanche crown! In a place where I couldn't recall ever seeing such a thing before, in 22 years and over 330 times skiing from Camp Muir. As I continued to skin higher up, it became obvious that it was definitely an avalanche crown.


Zoomed view of the avalanche crown.

As I slowly skinned upward, I had plenty of time to ponder the avalanche and its possible cause. Based on my usual close watch over the weather and NWAC telemetry, I realized the sequence of events which had likely happened to cause this. It had rained up to Camp Muir and higher, perhaps to 10500-11000 ft, at least twice in the previous week, on both November 1 and 3, with temps in the mid 30s °F on the Muir telemetry while very heavy precip was occurring throughout the WA Cascades. So obviously there had to be a water ice layer up to at least those elevations, possibly a fairly thick one. This ice layer was mostly buried by more recent snow, but still cropped out in places, most notably atop 9220 ft Moon Rocks which was largely covered in a sheet of shiny bluish ice, easily visible even from hundreds of feet away while skinning up.


Looking back at shiny bluish water ice layer atop Moon Rocks at left, with Mount Adams on the horizon.

Then on the last 2 days of the storm cycle, November 5-6, the snow level had plummeted down to 5000 ft and then even below 4000 ft, while the upper level flow turned northwesterly and moderate snowfall had occurred. This was the lovely powder snow that we were skinning up from the parking lot, and also the cause of the hard wind slab which had been deposited onto the SSE aspects of the steep slope to the left of Muir (normally this is a windward slope in the usual S or SW wet storm flows, but leeward in a NW flow). So several feet of windblown snow was loading onto this slope until it slid naturally, failing readily on the interface atop the water ice layer. At least, that's the sequence that made the most logical sense.


Panorama of the skintrack ascending smooth windpacked powder from about 9800 ft on the upper Muir Snowfield. (click for triple-size version)


So anyway, I continued to think a lot about this unusual avalanche while skinning slowly upward at my cold-afflicted pace. Little did I expect what would happen just a few minutes after these photos were taken.


Another view from near 9800 ft, with avalanche crown just above the skier at left, and the still-untracked AAA Gully just above the snowboarder at right.

Then at 2:37pm, about 7 minutes after taking that previous photo, my jaw dropped: Someone was skiing down AAA Gully!?!?! I almost could not believe that anyone was actually taking such a huge risk, especially with such an obvious sign of recent instability just to the left of the route, and with a water ice layer underlying all the recent new snow. It was mind-boggling, and I was fully prepared to see the whole gully rip in a massive avalanche that would sweep him to his death, or at the least deposit his broken body onto the upper part of the Muir Snowfield, perhaps deeply buried. But luckily for him, it didn't rip.


View from near 9900 ft of snowboarder descending the upper part of AAA Gully, with his skier partner watching from near the bottom. (click for double-size version)


His partner soon followed, on a snowboard instead. Again, it didn't slide. The skier's stopping location in the lower part of the gully, quite exposed to any large avalanche from above, is also highly suspect. He had a much safer stopping point available right where he made his last turn, near the rock rib at left.


The deed is done and they're both still alive.

Soon they were both on the flatter slopes of the Snowfield just below the bottom of the gully near 10000 ft, slapping high fives and having a chat with each other. I figured they would head down a few seconds later and that would be that. But they just stood there for minutes, as I continued to skin up the main skintrack, maybe 200 yards away from them.

Eventually I decided I had to try to do something, to make an attempt to try to talk with them, even though it would require breaking trail all the way over to them (and I was utterly exhausted, given the cough / cold mentioned earlier, so breaking trail for 200 yards was a big deal at 9900 ft on this day). For whatever reason, they stood there chatting for several minutes, and soon I was getting close, slowly carving a trail, soon within earshot. I was trying to figure out how best to approach them, never an easy task in these situations, especially for those such as myself who are given more to frankness than to diplomacy.

Once within easy conversation distance, I said hi, I got a few nice pics of you guys skiing the gully. They answered yeah, that was a sick line, it was awesome. And then I just asked the key question: So, how did you guys know that it wouldn't avalanche, when you dropped in from the top? Especially since the slope beside it had slid naturally in a large avalanche?

The skier's answer was kind of frightening: he said he dropped in, angled across, and it was very firm snow, so he thought it was all good and stable. !! They had apparently done no other avalanche hazard evaluation before dropping in -- not that there is any way to evaluate the slope stability of the 35-40 ° steep SSE-facing AAA Gully from its entrance at 10450 ft, which is on a flat spot about 10-20 yards wide along the east-facing Cowlitz Cleaver. It's a line you really have to be 100% certain is stable before dropping in (essentially no one ever climbs it to ski it, all ascend the Cowlitz Cleaver or Glacier from Camp Muir and then drop in).

So I told them the facts straight up: the firm snow they had skied at the top was a hard wind slab, the same exact kind that had slid naturally on the adjacent slope, and it was sitting on top of the same hard water ice layer, that was all over Camp Muir and everywhere else up there. I told them that they were lucky to be alive, lucky that AAA Gully hadn't also slid in a similar large avalanche when they dropped in. If it had slid, they would have been buried or broken or dead, and even best case, would have needed a helicopter evac to a hospital.

I also told them that in my 334 times skiing from Camp Muir, I could not recall seeing an avalanche crown on that slope which had slid, nor seeing any avalanche debris on the Muir Snowfield, so it was a highly unusual avalanche -- and so conditions were unusually dangerous on that slope, and therefore in AAA Gully too, which has the same slope angle and aspect. And I told them very frankly, that it was probably the single most dangerous thing that I had ever seen anyone do on the Muir Snowfield in all those 334 times skiing up there. (Of course, I've definitely seen some more dangerous and much stupider things done elsewhere on Rainier and other mountains.) I mentioned that I had skied AAA Gully maybe 15-20 times before, but never in conditions even remotely as dangerous as those of today. I emphasized the 2 huge red flags they had ignored: a large natural avalanche on the same slope angle and aspect that they planned to ski, and the hard water ice layer underneath all the snow up there.

They took my words of advice well, listening mostly quietly, with no backlash or anger or F-words or threats of violence towards me (all of which are, sadly, risks that one takes when one tries to help out by offering life-saving advice to those endangering themselves or others). I had assured them that I was not trying to upset them, but that I just wanted to make sure that my fellow skiers and snowboarders would be safe and not take these kind of risks, and not end up dead. Anyway, I had said what needed to be said, so I wished them well on the rest of their ski descent, stay safe and have a nice run. And then turned to break trail back towards Camp Muir, as they skied down the open untracked powder of the Muir Snowfield.



I really wanted to visit the avalanche debris pile to get some photos and measurements of the slide, especially since it was such an unusual avalanche. Actually, I can not recall seeing a single previous avalanche or crown or avalanche debris pile anywhere on the Muir Snowfield on any of those previous 330+ trips to Camp Muir, including 75 trips during winter season and 165 during the prime "avalanche season" months of November through April. So I've had plenty of chances to see a possible avalanche or debris up there. Maybe I'm forgetting something, and have seen an avalanche or two up there, but it's extremely uncommon in any case. Of course I've seen numerous avalanches and crowns and debris piles on many slopes all around and below and above the Muir Snowfield (Panorama Point, Pebble Creek rolls, Nisqually Chute, etc, etc) -- but the Muir Snowfield itself is a quite remarkable island of avalanche stability in a sea of surrounding frequent instability. And this avalanche was technically just off the Snowfield too, with its crown on a slope just above it, although its entire debris pile was deposited fully onto the Snowfield proper.


The closest shot that I did get while skiing down of the avalanche crown, debris pile, and the tracks in AAA Gully.

But it was 3pm when I arrived at Muir, with a cold 10 mph breeze blowing through camp, so I decided to just ski down instead of going over to the avalanche site. A nice run on decent windpacked powder up high, becoming just ridiculously smooth lovely powder below 8800 ft and especially below 8200 ft. And easily skiable all the way back to the parking lot without any ski damage, although a lot of careful route selection and caution in spots was needed below Pebble Creek. Almost all of the other 30-40 skiers had skied down via Pan Face, but I took the summer trail route out instead and it was much better and less rocky, with only about 5 other ski tracks having gone that way.


Panorama of the smooth untracked powder from about 7600 ft on the lower Muir Snowfield. (click for triple-size version)



Continued in next post, exceeded 20,000 character limit . . .


Continued from previous post . . .

November 8, 2018: Avalanche Size Measurements

Given my cough / cold, I wasn't sure if I would be back the next day, even though Thursday's forecast was even nicer with more sun and warmer temps and less wind. But thankfully I managed to motivate once again, even though I felt a bit worse than the previous day. Far less people were out skiing on Thursday, saw only maybe 10 skiers up on the Muir Snowfield, versus about 30-40 on Wednesday. Unexpectedly there had been a bit of wind overnight, which had partialy filled in the previous day's skin tracks and ski tracks on the Snowfield. And almost completely filled in the 2 tracks in AAA Gully, which were now just barely visible at all.


Slightly zoomed view from near 9500 ft of the avalanche crown and the now almost-erased ski tracks in AAA Gully. (click for double-size version)


Shot a bunch of zoomed photos of the avalanche crown as I skinned the last few hundred vert to Muir (taken with the amazing 24-960mm zoom on a Canon SX740 HS, easily the best pocketable ultrazoom camera I've ever used). I was trying to get a clear shot of the bed surface and also have some way to estimate crown height to reasonable accuracy. Turns out that a couple of the pics did manage to capture the icy bed surface, so my previous day's guess that the water ice layer was the interface on which the slab failed appears to be correct. But there really was nothing else that it could have been.


Moderately zoomed view from near 9800 ft of the avalanche crown and the bed surface, with many smooth icy areas visible. (click for double-size version)


My initial guess for the crown height while skinning up the previous day was maybe 1-3 ft. But in looking at various highly zoomed shots of the crown, I think that was an underestimate, and the highest part of the crown may be over 4 ft in height, on the left part of the crown near a couple outcropping rocks. I also made a measurement in pixels on the picture above, assuming the long straight segment of crown is about 150 ft in length, and that gives a max crown height of over 4 ft near those rocks. Note that most other portions of the crown have been partially buried by windblown snow since the avalanche, so they were originally taller than seen in the photos.


Panorama spanning over 280° from Camp Muir of the Cowlitz Cleaver and Glacier with Gibraltar Rock at center and Little Tahoma at right center. (click for triple-size version)


Got to Muir just before 3pm again like yesterday, but this time it was just gloriously nice up there, almost totally calm with temps near freezing, which felt more like the 40s °F. Had the entire place to myself for several minutes, before my friends David and Christy arrived.


Panorama spanning over 260° from Camp Muir of the upper Muir Snowfield with my friends skinning up the last bit. This forms a full 360° view with the previous panorama. (click for triple-size version)


While they were reassembling her splitboard (and then later remounting the bindings in the correct direction), I had plenty of time to ski over to the avalanche debris and take a bunch of photos plus a GPS fix on the debris terminus.


Hybrid satellite / USGS topo map with avalanche features marked, base map from https://caltopo.com/map.html#ll=46.833,-121.7366&z=17&b=hyb&o=t&n=0.2
(opacity of the topo overlay is adjustable using the drop-down menu at upper right)

The uppermost portion of the snowfield skied really nicely after traversing over close to the debris pile, somehow it was barely wind affected at all here. Kind of strange to have lovely silky powder turns just beside a large deposit of avalanche debris.


Looking SW across the debris pile just below 10000 ft, with sharp angular chunks of dense windslab (mostly 1-2 ft in size) scattered throughout the mostly pulverized debris.


Panorama from the side of the avalanche debris just below 10000 ft, unfortunately it was not possible to get this properly exposed. (click for triple-size version)



Panorama looking up from the toe of the avalanche debris at 9770 ft, with the crown and debris at center, and my ski tracks in beautiful non-wind-affected powder at right. (click for triple-size version)


The debris pile was roughly perhaps 400 ft wide, a bit wider than the total width of the crown.


Looking up from the toe of the avalanche debris at 9770 ft towards the crown at about 10300 ft. (click for double-size version)


The very straight linear segments of the crown are classic signs of a hard slab avalanche, along with the sharp angular chunks of dense windslab (mostly 1-2 ft in size) scattered throughout the mostly pulverized debris pile.


Zoomed view from the same spot as the previous photo, with the icy bed surface visible in many places. (click for double-size version)



Estimated avalanche measurements and data:

Avalanche occurred on November 5 or 6, actual date and time unknown.
Crown height is about 2-4 ft (60-120 cm), width about 300 ft (90 m), extending up to about 10300 ft elevation (3140 m).
Length of slab from crown to stauchwall (hard to discern) is very roughly about 200 ft (60 m), and slab is irregularly shaped.
Path length is about 1000 ft (300 m) from crown to debris terminus at 9770 ft (2980 m), for a vertical fall of over 500 ft (150 m) and thus an alpha angle of about 30°.
Debris pile width of roughly 400 ft (120 m).
Slope angle is about 36-37° at crown, decreasing to about 15° near debris terminus.
Slope aspect is SSE, roughly 140-150° true.
(Most values except crown height were estimated with the assistance of the measurement tools in CalTopo.)

Preliminary avalanche classification:
HS-NO-R4-D2.5-I
(hard slab - unclassified natural trigger - large size relative to path - could easily bury a person or almost bury a car - released at new snow/old snow interface, i.e. the water ice layer in this case)


[hr">Well my 2 partners were now done with the splitboard binding remount, so it was finally time to ski for real just after 4pm. The part above 8600 ft skied fairly well with nice powder in sections, but was definitely more wind affected and inconsistent than the previous day.



But below that elevation, it was still really excellent smooth powder and fantastic turns, with lovely glowing light as sunset neared.







[img width=1000 height=230">http://www.skimountaineer.com/TR/Images2018/RainierMuirSunsetPano3000-08Nov2018.jpg" />
Panorama of the still mostly smooth, mostly untracked powder from about 7600 ft on the lower Muir Snowfield. Compared with the last panorama from November 7 above taken from almost the same spot, the overnight effects of the wind are readily evident. (click for triple-size version)




Back out to the car at 5pm, just after sunset but well before dark. Slowed down a bit by all the careful weaving through rocky areas below Pebble Creek, but still no need to take the skis off all the way to the lot.


[hr">Addendum from November 11-12, 2018: Raised Ski Tracks Atop Ice Layer After Wind Scouring Event,
plus Pics and Measurements of the 2nd Avalanche Crown on Cowlitz Headwall Below Gibraltar Rock near 11400 ft


Several commenters below and on the TAY Facebook page (see https://www.facebook.com/groups/turnsallyear/permalink/10156773653829699/) have noted a second large avalanche crown on Cowlitz Headwall below Gibraltar Rock. My pictures which show that crown from November 7 and 8 at Camp Muir are all heavily shadowed, since the sunlight goes completely off that SE-facing aspect by 2pm (and partially by 1pm) this time of year, well before I was arriving at Camp Muir.


View looking towards the summit from just east of the Muir public shelter on November 7, with the 2nd avalanche crown visible at right center on Cowlitz Headwall below Gibraltar Rock.


Enlarged and cropped section of the previous photo.


I was back skiing Muir again on Sunday-Monday, November 11-12, and running on a similar arrival schedule, so in order to get a good clear sunlit shot of the crown, I took some highly zoomed shots from much farther down the Muir Snowfield well before 1pm when that face was still fully sunlit.


Extreme zoomed view of the 2nd avalanche crown on Cowlitz Headwall below Gibraltar Rock on November 12, taken with the full 960mm equivalent zoom of the Canon SX740 HS from about 7600 ft on Muir Snowfield.

One interesting thing visibile on November 11-12 was that those ski tracks in AAA Gully had reappeared as raised tracks -- previously, they had almost entirely filled in and disappeared by the next day November 8 due to a very minor breezy period overnight. However, the day after that a storm system came through, and high winds on November 9 gusted to over 60 mph from the WSW at Camp Muir for 3 hours. This scoured away much of the snow atop the ice layer in AAA Gully, leaving the firmer compacted snow of those tracks as arcs of snow extending 1-2 ft above the solid layer.


Partially zoomed view of both avalanche crowns and the raised ski tracks in AAA Gully on November 11, from near 9000 ft on Muir Snowfield. (click for double-size version)



Closer view of the avalanche crown and raised ski tracks in AAA Gully on November 12, from near 9900 ft on Muir Snowfield. (click for double-size version)


The icy layer in between patches of raised snow is more easily seen in this zoomed view, especially along the left side and maybe also the right side. It's very unusual to be able to get such a nice dissected view of what was really under the windslab in AAA Gully:


Zoomed view of the raised ski tracks in AAA Gully on November 12, from near 9900 ft on Muir Snowfield. (click for double-size version)



This view from Camp Muir show the full path of the Cowlitz Headwall avalanche, from the crown near 11400 ft all the way down into a large crevasse near 10700 ft on Cowlitz Glacier.


Zoomed view of the avalanche crown on Cowlitz Headwall and the debris pile below it on the Cowlitz Glacier on November 11 from Camp Muir. (click for double-size version)


This larger topo map shows both of the avalanche crowns and paths:

[img width=800 height=800">http://www.skimountaineer.com/TR/Images2018/RainierMuirCowlitzAvalanchesHybridTopoMap1600-08Nov2018.jpg" />
Hybrid satellite / USGS topo map with both sets of avalanche features marked. (click for double-size version)

Base map from https://caltopo.com/map.html#ll=46.8412,-121.7359&z=17&b=hyb&o=t&n=0.2
(opacity of the topo overlay is adjustable using the drop-down menu at upper right)

Estimated avalanche measurements and data for the Cowlitz Headwall avalanche:

Overall, this slab has a slightly longer crown and path length, and released on a slightly steeper and somewhat more easterly-facing slope, than the slab above the Muir Snowfield.

Avalanche occurred on November 5 or 6, actual date and time unknown.
Crown height is very roughly estimated at about 3-4 ft (1 meter), width about 400 ft (120 m), extending up to about 11400 ft elevation (3470 m).
Length of slab from crown to stauchwall (hard to discern) is unknown, and slab is roughly rectangular.
Path length is about 1300 ft (400 m) from crown to debris terminus at 10700 ft (3260 m), for a vertical fall of over 700 ft (210 m) and thus an alpha angle of about 32°.
Debris pile width unknown, and extends into very large crevasse, so length and alpha angle are calculated only to the lip of this crevasse.
Slope angle is about 40° at crown, decreasing to about 20° near debris terminus.
Slope aspect is ESE, roughly 115-125° true.
(Most values except crown height were estimated with the assistance of the measurement tools in CalTopo.)

Preliminary avalanche classification:
HS-NO-R4-D3-I
(hard slab - unclassified natural trigger - large size relative to path - could easily bury a car - released at new snow/old snow interface, i.e. the water ice layer in this case)


[hr">Here's one more interesting panorama from a 2nd visit to the Muir avalanche debris on November 11, just to see what changes the wind event had wrought:

[img width=1000 height=230">http://www.skimountaineer.com/TR/Images2018/RainierMuirAvalancheDebrisSidePano3000-11Nov2018.jpg" />
Panorama from the side of the Muir Snowfield avalanche debris just below 10000 ft on November 11, with my raised ski tracks from November 8 visible at left above the icy layer, scoured out by the November 9 wind event. (click for triple-size version)


And to conclude this addendum, here is a lovely solar halo that was visible for several hours on November 12:

[img width=1000 height=260">http://www.skimountaineer.com/TR/Images2018/RainierMuirSolarHaloPano3000-12Nov2018.jpg" />
Panorama from about 9600 ft on the Muir Snowfield with 22-degree solar halo at left. (click for triple-size version)




Weather Forecasts and Data:

Here is the NWS Rainier forecast for the day of this report:

Mount Rainier Recreational Forecast
National Weather Service Seattle WA
337 AM PST Wed Nov 7 2018

SYNOPSIS...High pressure will build over the region and give mostly sunny skies and dry weather to Mount Rainier National Park today and Thursday. A weak weather system will bring a little rain and snow Friday. Showers could linger Saturday, but Sunday and Monday should be dry. Rain and snow may return Tuesday.

IMPACTS...Strong winds near the summit on Friday will make it difficult to move safely and could produce local whiteout conditions. A high level of skill and experience in alpine terrain, including use of GPS, is recommended for navigation and camping in these conditions.

WEDNESDAY...Sunny. Freezing level near 3500 feet increasing to 4500 feet in the afternoon.
WEDNESDAY NIGHT...Mostly clear. Freezing level near 5500 feet.
THURSDAY...Sunny. Freezing level near 6000 feet increasing to 8000 feet in the afternoon.
THURSDAY NIGHT...Partly cloudy. Freezing level near 8000 feet.
FRIDAY...Mostly cloudy with a chance of rain and snow in the morning, then rain and snow likely in the afternoon. Light snow accumulations. Snow level near 3500 feet increasing to 5000 feet in the afternoon.

Temperature and wind forecasts for selected locations.

                       Wed    Wed    Thu    Thu    Fri
                            Night         Night

Summit   (14411 FT)     -1      5     10     14     10
                      N 30   N 35  NW 25  NW 25   W 50

Camp Muir(10188 FT)     16     22     25     26     24
                      N 15   N 15  NW 15  NW 15   W 30

Paradise  (5420 FT)     35     26     42     27     40
                      W  5   N  5   W  5   Calm  NW 15

Longmire  (2760 FT)     45     29     50     30     47
                     SW  5   E  5  SW  5  NE  5   W  5

++ Temperatures and wind for the summit and Camp Muir are average
   conditions expected in the free air at those elevations.
++ Temperatures for Paradise and Longmire are the expected highs and
   lows. Wind is the average wind expected during that period.

Extended Forecast...

FRIDAY NIGHT...Mostly cloudy with a chance of showers. Snow level near 4500 feet decreasing to 3500 feet after midnight.
SATURDAY...Partly sunny with a slight chance of showers. Snow level near 3000 feet.
SATURDAY NIGHT...Partly cloudy. Freezing level near 6000 feet.
VETERANS DAY...Mostly cloudy. Freezing level near 8000 feet.
SUNDAY NIGHT...Mostly clear. Freezing level near 10000 feet.
MONDAY...Sunny. Freezing level near 11000 feet.
MONDAY NIGHT...Mostly clear. Freezing level near 11500 feet.
TUESDAY...Mostly cloudy with a slight chance of rain and snow. Snow level near 4500 feet increasing to 6000 feet in the afternoon.



And the forecast from 3 days earlier, which covers the period when the windlab was deposited and then avalanched:

Mount Rainier Recreational Forecast
National Weather Service Seattle WA
412 AM PST Sun Nov 4 2018

SYNOPSIS...Cold front moving through the park early sunday morning. Moist northwesterly flow aloft continuing into Tuesday keeping showers in the forecast. An upper level ridge will build offshore Tuesday night and remain through at least Friday. Weather systems moving over the top of the ridge could reach the park next weekend.

IMPACTS...Strong winds near the summit will make it difficult to move safely and could produce local whiteout conditions Sunday through Tuesday. A high level of skill and experience in alpine terrain, including use of GPS, is recommended for navigation and camping in these conditions.

SUNDAY...Windy. Rain and snow in the morning, then showers likely in the afternoon. No snow accumulation near Paradise. Snow level near 6500 feet decreasing to 5500 feet in the afternoon.
SUNDAY NIGHT...Windy. Showers likely in the evening, then a chance of showers after midnight. Snow accumulation near Paradise up to 4 inches. Snow level near 4500 feet.
MONDAY...Breezy, showers. Snow accumulation near Paradise of 2 to 7 inches. Snow level near 4500 feet.
MONDAY NIGHT...Showers in the evening, then showers likely after midnight. Moderate snow accumulations. Snow level near 4000 feet.
TUESDAY...Partly sunny with a chance of showers. Snow level near 3500 feet.

Temperature and wind forecasts for selected locations.

                       Sun    Sun    Mon    Mon    Tue
                            Night         Night

Summit   (14411 FT)      4      6      0     -4      0
                      W 60   W 50   W 50  NW 40  NW 40

Camp Muir(10188 FT)     18     16     15     14     13
                      W 35   W 35   W 30   W 25  NW 20

Paradise  (5420 FT)     36     30     34     26     31
                      W 30  NW 25   W 20   W 20   W 15

Longmire  (2760 FT)     46     38     43     36     41
                      W 15   W 15   W 10   W 10   W 10

++ Temperatures and wind for the summit and Camp Muir are average
   conditions expected in the free air at those elevations.
++ Temperatures for Paradise and Longmire are the expected highs and
   lows. Wind is the average wind expected during that period.

Extended Forecast...

TUESDAY NIGHT...Mostly cloudy with a chance of showers. Snow level near 3500 feet.
WEDNESDAY...Mostly sunny. Freezing level near 5000 feet.
WEDNESDAY NIGHT...Mostly clear. Freezing level near 5500 feet.
THURSDAY...Sunny. Freezing level near 7000 feet.
THURSDAY NIGHT...Partly cloudy. Freezing level near 7500 feet.
FRIDAY...Partly sunny. Freezing level near 8500 feet.
FRIDAY NIGHT...Partly cloudy. Freezing level near 8500 feet.
SATURDAY...Partly sunny. A slight chance of rain and snow. Snow level near 8000 feet.



And the forecast from 3 days before that, which covers the period when the water ice layer was deposited. Note that NWAC telemetry from Camp Muir indicates that it rained much higher than this forecast predicted, to about 10500-11000 ft on both Thursday Nov 1 and Saturday Nov 3:

Mount Rainier Recreational Forecast
National Weather Service Seattle WA
425 AM PDT Thu Nov 1 2018

SYNOPSIS...A warm front will move through the park later Thursday followed by a cold front Friday morning. More systems will move through the park over the weekend into Monday. A weak ridge of high pressure could give the park a dry day in the middle of next week.

IMPACTS...Strong winds in alpine regions on the mountain, including the Muir snowfield, will make it difficult to move safely and could produce local whiteout conditions Thursday through Saturday. A high level of skill and experience in alpine terrain, including use of GPS, is recommended for navigation and camping in these conditions.

THURSDAY...Windy. Rain and snow. No snow accumulation near Paradise. Snow level near 9000 feet.
THURSDAY NIGHT...Windy. Mostly cloudy with a chance of rain and snow in the evening, then rain and snow after midnight. No snow accumulation near Paradise. Snow level near 8500 feet.
FRIDAY...Windy. Rain and snow in the morning, then showers in the afternoon. Rain may be heavy at times in the morning. No snow accumulation near Paradise. Snow level near 7500 feet.
FRIDAY NIGHT...Windy. Mostly cloudy. A chance of showers in the evening, then a chance of rain and snow after midnight. Snow level near 5500 feet.
SATURDAY...Mostly cloudy with a chance of rain and snow. Snow level near 5500 feet.

Temperature and wind forecasts for selected locations.

                       Thu    Thu    Fri    Fri    Sat
                            Night         Night

Summit   (14411 FT)     20     17      6     16     21
                      W 60   W 70   W 70  NW 60   W 60

Camp Muir(10188 FT)     31     31     20     25     26
                      W 45   W 55   W 45  NW 40   W 45

Paradise  (5420 FT)     47     40     42     33     40
                      W 25   W 30   W 30  NW 20   W 15

Longmire  (2760 FT)     52     46     49     40     48
                     NW 10  NW 10   W 15   W 10   W  5

++ Temperatures and wind for the summit and Camp Muir are average
   conditions expected in the free air at those elevations.
++ Temperatures for Paradise and Longmire are the expected highs and
   lows. Wind is the average wind expected during that period.

Extended Forecast...

SATURDAY NIGHT...Windy. Rain and snow. Snow level near 7000 feet.
SUNDAY...Rain and snow. Snow level near 7000 feet.
SUNDAY NIGHT...Mostly cloudy with a chance of rain and snow. Snow level near 5500 feet.
MONDAY...Rain and snow likely. Snow level near 5000 feet.
MONDAY NIGHT...Mostly cloudy with a chance of rain and snow. Snow level near 5500 feet.
TUESDAY...Mostly cloudy with a chance of showers. Snow level near 5500 feet.
TUESDAY NIGHT...Mostly cloudy with a chance of showers. Snow level near 5000 feet.
WEDNESDAY...Partly sunny. Freezing level near 5500 feet.



And with the addendum above from November 11-12, I might as well add the forecast covering that period too:

Mount Rainier Recreational Forecast
National Weather Service Seattle WA
347 AM PST Sun Nov 11 2018

SYNOPSIS...High pressure will dominate the region through Monday. A front will bring rain to Washington late Tuesday, spreading inland Tuesday night. The system dissipates over the area Wednesday, so clouds and light precipitation may continue. Another mainly dry period is expected Thursday and Friday as high pressure moves across the area. A system could bring unsettled weather by next weekend, but confidence is low toward the end of the forecast period.

IMPACTS...Strong winds near the summit will make it difficult to move safely and could produce local whiteout conditions. A high level of skill and experience in alpine terrain, including use of GPS, is recommended for navigation and camping in these conditions.

SUNDAY...Sunny. Freezing level near 5000 feet increasing to 9000 feet in the afternoon.
SUNDAY NIGHT...Mostly clear. Freezing level near 8000 feet.
MONDAY...Mostly sunny. Freezing level near 8000 feet increasing to 11500 feet in the afternoon.
MONDAY NIGHT...Partly cloudy. Freezing level near 9500 feet.
TUESDAY...Partly sunny. Freezing level near 10000 feet.

Temperature and wind forecasts for selected locations.

                       Sun    Sun    Mon    Mon    Tue
                            Night         Night

Summit   (14411 FT)     13     15     16     16     14
                      N 40  NW 25   W 10  SW 25  SW 45

Camp Muir(10188 FT)     27     32     34     33     30
                      N 15   N  5   W  5  SW 20  SW 30

Paradise  (5420 FT)     40     25     46     29     43
                     NE 10  NE 15   E  5   W  5   W 10

Longmire  (2760 FT)     50     34     50     36     49
                      E  5   E 15   E 10   E  5   W  5

++ Temperatures and wind for the summit and Camp Muir are average
   conditions expected in the free air at those elevations.
++ Temperatures for Paradise and Longmire are the expected highs and
   lows. Wind is the average wind expected during that period.

Extended Forecast...

TUESDAY NIGHT...Rain and snow. Snow level near 5000 feet.
WEDNESDAY...Rain and snow. Snow level near 6500 feet.
WEDNESDAY NIGHT...Mostly cloudy with a chance of showers. Snow level near 5500 feet.
THURSDAY...Mostly cloudy with a slight chance of showers. Snow level near 5000 feet.
THURSDAY NIGHT...Mostly cloudy. Freezing level near 9500 feet.
FRIDAY...Mostly cloudy. Freezing level near 9500 feet.
FRIDAY NIGHT...Mostly cloudy. Freezing level near 9500 feet.
SATURDAY...Partly sunny with a slight chance of showers. Snow level near 6000 feet.



[hr]Here is the NWAC telemetry from Paradise and Camp Muir covering the 10 day period through the days of this report. Note that the precip gauge at Paradise was malfunctioning throughout most of this period, with the message [i]"Precipitation gauge undermeasuring, repairs underway"[/i] added atop the NWAC data file. As stated on the current message below, it was repaired on November 8, with a sudden burst of "precip" recorded from noon onward, even on a completely dry and sunny day. This is due to unmelted snow sitting atop the precip gauge, which melted due to the warm temperatures and also (presumably) the precip gauge heater was fixed then too.

[img]http://www.skimountaineer.com/TR/Images2018/RainierParadiseMuirTelemetryData-09Nov-30Oct2018a.png[/img]
[img]http://www.skimountaineer.com/TR/Images2018/RainierParadiseMuirTelemetryData-09Nov-30Oct2018b.png[/img]
[img]http://www.skimountaineer.com/TR/Images2018/RainierParadiseMuirTelemetryData-09Nov-30Oct2018c.png[/img]
[img]http://www.skimountaineer.com/TR/Images2018/RainierParadiseMuirTelemetryData-09Nov-30Oct2018d.png[/img]
[img]http://www.skimountaineer.com/TR/Images2018/RainierParadiseMuirTelemetryData-09Nov-30Oct2018e.png[/img]


In addition to the NWAC telemetry, weather data is manually recorded at Paradise (almost) daily by park rangers. Given the malfunctioning precip gauge at the NWAC site throughout this period, it is especially useful to look at the manual precip values, which are recorded using an old-fashioned precip bucket located just a few yards away from the NWAC site. Recent manual data is available from NOWData - NOAA Online Weather Data at https://w2.weather.gov/climate/xmacis.php?wfo=sew (select the location "Rainier Paradise, WA" and "Daily data for a month", then pick a month to view it). Here is the daily data for all of October 2018 and the start of November (missing days in this data set are sometimes filled in later from the paper records before the data is quality-controlled and archived):

[img]http://www.skimountaineer.com/TR/Images2018/RainierParadiseClimateData-Oct2018.png[/img]
[img]http://www.skimountaineer.com/TR/Images2018/RainierParadiseClimateData-Nov2018.png[/img]

Note in particular the heavy precipitation recorded from October 31 to November 2 and again on November 4-5, when the malfunctioning NWAC precip gauge was recording very little at all.



THANK YOU so much for your very detailed trip reports. This is incredible info and I'm sure I speak for many when I say the effort you put into this TR is very much appreciated!

Yesterday, I also noticed a big crown underneath Gibraltar rock, in the snowfield beside cadaver gap. Looked like it came from the same event, or perhaps it came down with the wind event Friday.

Nice work on all this, Amar. It's a good opportunity to remind everyone on TAY that NWAC wants your snowpack and avalanche observations. Submissions can be made on our mobile app, as well as via the "observations" tab on the website. Have a fun and safe season!

Wow.

Thanks for the detailed report - it is interesting to read both the avalanche and human factor assessment.

Kudos for tactfully addressing this with the skiers. I've found myself in situations when I am not sure if I should confront someone when I see something sketchy (avalanche beacons on dogs, anyone?) - I am impressed with how it sounds like you handled this.

And, way to get after the early season turns!

Thanks for posting this - I was up there on Thursday and saw that crown and the one near Gibraltar Rock.  Your explanation is much appreciated - and a good reminder that dangers on that route lurk in the sidelines.

As always, Amar, very thought provoking. You drive home the point of how critical it is to make observations of the conditions on the ascent. But, what really struck me, was how important it is to be informed of the weather conditions in the days (and weeks) BEFORE going out. I'm not as diligent as I should be in this regard, especially in the months when NWAC is not forecasting.

So if the surface is firm, it must be stable, go for it.

If it's soft powder, then you ski it like a movie star.

This is a quality algorithm.

Amar -

Thanks for the educational post, especially from someone who spends so much time up there and is quite aware of the conditions.  Very helpful.

Thanks for the comments, folks.

I've just posted an addendum to the original report (at the end of Reply #1) with several photos and measurements of the 2nd avalanche crown on Cowlitz Headwall, mostly taken on subsequent trips up there on November 11-12, along with photos of raised ski tracks visible above the icy layer in AAA Gully following a wind scouring event on November 9.



author=jeremyallyn link=topic=41020.msg162720#msg162720 date=1541992964">
Nice work on all this, Amar. It's a good opportunity to remind everyone on TAY that NWAC wants your snowpack and avalanche observations. Submissions can be made on our mobile app, as well as via the "observations" tab on the website. Have a fun and safe season!


Thanks for all of the information! I'd like to echo the comment about submitting the observation to NWAC as well to be included in their database. It's far more likely to be useful for future data mining there than it is on a forum.

https://www.nwac.us/observations/submit/

Thanks again!

Tx for the detailed report, and the reminder that early season can have avy hazards before some people start thinking about it. 

Reply to this TR

14305
nov-7-2018-camp-muir-avalanche-red-flags-ignored
Amar Andalkar
2018-11-10 19:20:21