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Snowpack Summary January 27, 2023
Posted by Allen Giernet @ 6:20 am (this summary expires in 24 hours)
This summary applies to backcountry areas only.
The Bottom Line –
Significant Warmer is forecast for today and Saturday, Loose Wet Avalanches will be likely as the day time highs increase into the afternoon. Fast firm conditions will start the day and give way to softening snow as temperatures rise and sun affects the snow surfaces on all but the most northerly and sheltered aspects. Look for signs of rapidly warming snow roller balls and pinwheels, firm snow becoming soft and sinking to boot top depth through the day. Start and finish your days early. If your reading this forecast you probably are starting too late for those solar aspects. Be prepared for fast firm conditions in the early morning and bring the proper tools and skills to use them.
Please share your observations with us at the avalanche center Submit Reports page.
Posted by Allen Giernet @ 6:20 am (this summary expires in 24 hours)
This summary applies to backcountry areas only.
The Bottom Line –
Significant Warmer is forecast for today and Saturday, Loose Wet Avalanches will be likely as the day time highs increase into the afternoon. Fast firm conditions will start the day and give way to softening snow as temperatures rise and sun affects the snow surfaces on all but the most northerly and sheltered aspects. Look for signs of rapidly warming snow roller balls and pinwheels, firm snow becoming soft and sinking to boot top depth through the day. Start and finish your days early. If your reading this forecast you probably are starting too late for those solar aspects. Be prepared for fast firm conditions in the early morning and bring the proper tools and skills to use them.
Please share your observations with us at the avalanche center Submit Reports page.
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.
Firm and Icy Surfaces firm and icy surfaces can cause long slide for life scenarios. Travel can be difficult to vary dangerous. Self arrest may be difficult to impossible. Micro spikes are not recommended for these conditions. Ice Axe and Crampons with proper training and skill are necessary tools for travel in these conditions. A slip and fall on these surfaces in steep terrain can lead to a long slide with tragic results.
General Summary
#1 Problem Loose Wet Avalanches – With significant warming forecast for today and Saturday Loose Wet Avalanches will be likely on NE,E,SE,S,SW,W,&NW aspects especially slopes with significant solar input. Watch for the signs of Wet Snow instability, Roller balls or pinwheels especially from rock bands and outcroppings, firm snow becoming unsupportable and sinking into boot top depth. These are all signs of wet snow instability and should you encounter these conditions you should move out of steeper terrain >30° or change aspect to a more sheltered area. These slides will generally not bury you but can knock you off your feet and drag you through nasty terrain or over drop offs with hazardous results. The Baldy bowl is a prime locations for these type of slides and are commonly seen in one the most user heavy areas of our mountains.
#2 Problem Firm or Icy Conditions - due to the past few days of cold temperatures and overnight freezing. This will bring fast firm slide for life conditions. Use of ice axe and crampons is recommended with the skills to use them. Slide for life scenarios are one of our biggest hazards in the So Cal mountains. More rescues are initiated during the winter time due to these conditions than any other hazard.
Conditions will change significantly through the day. Be prepared for firm, icy conditions early that will transition through the day as you travel with an eye on aspect and elevation changes. Start early and finish early while these problems remain on our list. Use your own judgement and constantly evaluate conditions while you travel. Move to terrain <30° if you have any uncertainty or doubt about the conditions. Exercise caution if venturing out into the mountains and use avalanche protocols, travel with a partner and bring your beacon, shovel and probe.
For Sunday another cold front will move in bringing icy firm conditions to the top of our list. Snow is forecast for Sunday through Monday with up to 12” possible at the 8,000’ elevation. Moderate to strong Southwest winds will accompany this storm which will bring Storm Slab and Wind Slab avalanches onto our problem list.
Please share any information when you are out in the mountains. Even a photo is helpful. Submit observations to Submit Reports page.
Exercise caution on slopes over 30° as these conditions will exist throughout all mountain ranges. Always exercise caution when entering into winter mountain areas. Bring a Beacon Shovel and Probe and know how to use them. Travel with a partner and make conservative decisions.
#1 Problem Loose Wet Avalanches – With significant warming forecast for today and Saturday Loose Wet Avalanches will be likely on NE,E,SE,S,SW,W,&NW aspects especially slopes with significant solar input. Watch for the signs of Wet Snow instability, Roller balls or pinwheels especially from rock bands and outcroppings, firm snow becoming unsupportable and sinking into boot top depth. These are all signs of wet snow instability and should you encounter these conditions you should move out of steeper terrain >30° or change aspect to a more sheltered area. These slides will generally not bury you but can knock you off your feet and drag you through nasty terrain or over drop offs with hazardous results. The Baldy bowl is a prime locations for these type of slides and are commonly seen in one the most user heavy areas of our mountains.
#2 Problem Firm or Icy Conditions - due to the past few days of cold temperatures and overnight freezing. This will bring fast firm slide for life conditions. Use of ice axe and crampons is recommended with the skills to use them. Slide for life scenarios are one of our biggest hazards in the So Cal mountains. More rescues are initiated during the winter time due to these conditions than any other hazard.
Conditions will change significantly through the day. Be prepared for firm, icy conditions early that will transition through the day as you travel with an eye on aspect and elevation changes. Start early and finish early while these problems remain on our list. Use your own judgement and constantly evaluate conditions while you travel. Move to terrain <30° if you have any uncertainty or doubt about the conditions. Exercise caution if venturing out into the mountains and use avalanche protocols, travel with a partner and bring your beacon, shovel and probe.
For Sunday another cold front will move in bringing icy firm conditions to the top of our list. Snow is forecast for Sunday through Monday with up to 12” possible at the 8,000’ elevation. Moderate to strong Southwest winds will accompany this storm which will bring Storm Slab and Wind Slab avalanches onto our problem list.
Please share any information when you are out in the mountains. Even a photo is helpful. Submit observations to Submit Reports page.
Exercise caution on slopes over 30° as these conditions will exist throughout all mountain ranges. Always exercise caution when entering into winter mountain areas. Bring a Beacon Shovel and Probe and know how to use them. Travel with a partner and make conservative decisions.
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Disclaimer:
This Bulletin is designed to generally describe conditions where local variations always occur. Travelers are advised to exercise caution and make slope specific evaluations. As always, please treat this bulletin with appropriately guarded skepticism and make your own assessments. Help to provide more information to the community by reporting your observations
This Bulletin is designed to generally describe conditions where local variations always occur. Travelers are advised to exercise caution and make slope specific evaluations. As always, please treat this bulletin with appropriately guarded skepticism and make your own assessments. Help to provide more information to the community by reporting your observations
Latest Observtions
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Observation type -
Snowpack Location - San G Wilderness/ Jepson Date (yyyymmdd) - 20230121 Comment - We dug the pit on a NNE aspect with visible wind deposits to get an idea of the conditions in the Jepsen chutes. The rain crust that we found at about a meter depth in the pit location was exposed in some wind-scoured locations. Top 10 cm were a hard wind slab with fracture propagation on isolation. For the rest of the snowpack ECT resulted in no fracture. Total snow depth: 305 cm Snow pit: Pencil 0-5 cm Knife to 30 cm 4 Fingers grains to 70 cm Thin ( Finger to 90 cm Knife to 100 cm Loose layer (~1 cm thickness) at 105 cm Pencil to 145 cm Knife to 150 cm Pencil to 200 cm rain crust (2.5 cm thick) at 200 cm Pencil to fingers to 290 cm 4 fingers to 295 cm, ECTPV weak layer at 295 knife 295 to 305 --> 10 cm think wind slab, fracture propagating on isolation (consistent with small releases observed on leeward N-NW aspects below jepsen ridge) Snow temperature was -9C at 15cm below the surface, with a temperature gradient of less than 0.5C / 10cm. |
Observation type
Snowpack Location - Heart Bar Peak Date (yyyymmdd) -20230121 Comment Saturday AM tour near treeline in the SG mountains with the goal of scoping higher elevation snowpack and assess stability. Key takeaways on the approach: - Evidence of massive windloading present near ridgelines in the form of small cornices and wind lips. - Solar input was quickly melting huge chunks of rime ice from trees, littering ground with glass-like debris - Surface hoar observed at the start of the tour on clear, high elevation spots (see photo). It was getting zapped by the sun and warmer temps by early afternoon. - Snow surface is highly variable on all but the most protected aspects. Currently a mix of ice, windboard, sastrugi and granular wind-drifted snow. - Some faceted snow on highest, steepest aspects. Looks like it's rounding as temps have steadily increased in recent days. Dug a pit on a NNE test slope near where we planned to ski, that was obviously affected by windloading, so take with a grain of salt. - 175cm deep - 4F 155-175 - melt/freeze crust at 155 - pencil hard from 155 to ground with faintly visible layers (no pronounced crusts, though) - CT12 failure at 165, Q3 shear. - column was cohesive and seemingly well bonded below soft snow surface Key takeaways for me are that the snowpack does appear to be bonding, although the primary concerns are still large swaths of boilerplate/ice and some breakable crusts that pose danger in exposed terrain. |
Observation type
Snowpack Location - Waterman Ski Area Date (yyyymmdd) - 20230119 Comment - Snow pit and conditions description Snow pit near the base of Waterman. 9am 1/19/21 NE aspect 6944’ Top Dust on 2 inch sun crust 2-3 inch 4F sugary layer 0.5-1inch rain crust 1 inch 1F snow 7-8 inches P hard consolidated snow Ground Above freezing temps Wind 0-5mph Clear skies Had decent skiing on shallow snow in the late morning on a S facing aspect near the same elevation. Had very firm but enjoyable conditions on N/NE aspects in the early afternoon at Waterman. Top melt-freeze crust was cracking a bit on the skin up but only broke through a couple times on the way down. |
Observation type
Snowpack Location - Big Pines Date (yyyymmdd) - 20230117 Comment - Comment Lunchtime tour on Tuesday to scope out the snow that fell late Monday. This round of precip was much colder and thankfully not followed by rain or heavy winds. From 7000-7500 I'd estimate 5-8cm of soft, dry snow fell on a base of refrozen mank. Above 8k it was closer to 10-15cm. Wind loading on NE aspects continues to be the big takeaway, with large mounds of drifted snow and pillows evident near ridgelines. One obviously wind loaded test slope I stomped on cracked immediately and propagated several feet in each direction (see photo). Other areas closer to my turnaround point at 8200ft had large cornices standing 130cm+ high. Will continue to monitor for how the next period of dry, cool days affects the current soft snow surface. |
General Caution
You should always use safe terrain management and carry avalanche rescue equipment in the backcountry. Most avalanches are triggered by someone in the party or the victim. Practice with your rescue gear often and be prepared should the worst happen. Though we do not have an avalanche forecast center in this area as of yet, the information posted and shared here as well as the resources available on this site will help to make informed decisions for your backcountry travels. Use avalanche forecasts in your travels wherever available and be aware that avalanche ratings are general information. Elevation, location, geographic variability’s, slope aspect and angle all have effects on the particular area you travel in. This is only one piece of the information you should use in your decision making process. There is no substitute for avalanche education, for more resources and information as well as education please refer to our resources page.
You should always use safe terrain management and carry avalanche rescue equipment in the backcountry. Most avalanches are triggered by someone in the party or the victim. Practice with your rescue gear often and be prepared should the worst happen. Though we do not have an avalanche forecast center in this area as of yet, the information posted and shared here as well as the resources available on this site will help to make informed decisions for your backcountry travels. Use avalanche forecasts in your travels wherever available and be aware that avalanche ratings are general information. Elevation, location, geographic variability’s, slope aspect and angle all have effects on the particular area you travel in. This is only one piece of the information you should use in your decision making process. There is no substitute for avalanche education, for more resources and information as well as education please refer to our resources page.
