Moderate snow storm 1st January 2023

UPDATE Thursday 5th January 2023: We are just catching the southern edge of the highly-publicized storm currently passing through central California. By dusk today it had rained 0.68 inch in Idyllwild, and Long Valley had 1.5 inches of fresh snowfall. The system was generally very mild, with the freeze level near 8000 ft, but this is expected to drop overnight, by which time the precipitation will have largely passed. The next comprehensive update to the Report will hopefully be tomorrow evening, Friday 6th.

UPDATE Tuesday 3rd January 2023: Following another minor overnight snow storm – our fourth in the past week – Anabel and I briskly broke trail up Devil’s Slide to Saddle Junction early this morning. A short video summary of what we found is available here. The high country was above the weather most of the night, and added an inch of fresh snow at most, however there were 2.25 inches in Idyllwild, and also roughly the same fresh snow depth at Humber Park and Saddle Junction. Current known total accumulations are 4 inches in Idyllwild, 6 inches at Devil’s Slide Trailhead, 9 inches at Saddle Junction, and 8 inches at Long Valley. Sadly at first light the precipitation turned to drizzle at all elevations on the western slope between (at least) Idyllwild and 8100 ft at Saddle Junction, and consequently the snow quality was deteriorating fast at mid elevations this morning. It continued to drizzle in Idyllwild all day, slowly accumulating to about 0.25 inch of rain.

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A positive start to the new year, this is a summary of conditions following the fifth Pacific storm (but only the third significant snowfall) of winter 2022/23 to impact the San Jacinto mountains. Forecasts indicate we will get a few more inches of snow overnight on 2nd-3rd January, and again on Thursday 5th January. The second week of January is expected to be relatively warm and sunny, so extensive melting will start, especially at mid elevations. Clearly conditions are expected to continue to change over the next week or two, so this summary is intentionally brief.

The storm started relatively mild, as might be expected from an “atmospheric river” system pulling moisture in from warmer latitudes, and as a result the freeze level was above 6500 ft for most of the storm, with rain as high as 9000 ft, before finally falling to about 5000 ft on the afternoon of Sunday 1st. Precipitation at the elevation of Idyllwild fell largely as rain (1.79 inches) before turning to “thunder snow” starting at 1235 on Sunday afternoon (currently accumulated to 1.5 inch but still snowing as I write this).

The total snow accumulation was ultimately somewhat below prior forecasts, with San Jacinto Peak receiving about 9-10 inches overnight (rather than the 12-16 anticipated). However subsequent light snow on Sunday 1st improved the depths by another couple of inches.

As I snowshoed down past 9000 ft elevation it was clear from a layer of ice underfoot that after a light snowfall, there had been rain on top of snow, before it started snowing again on top of that Sunday morning. This makes for less than perfect snowshoeing conditions, but still preferable to postholing.

Conditions prior to this storm had been unsettled for several days, with a minor storm overnight on 27th-28th December. This was a very mild system, producing rain to 9000 ft elevation (and consequently very icy conditions), and one inch of fresh snow above about 9000 ft elevation (increasing to 1.5 inch >10,000 ft). There was a further 0.5 inch dusting of snow above 8000 ft on Thursday 29th (as I describe in this video). Conditions are forecast to remain very unsettled for the first week of January. At least two further minor storm systems are forecast, overnight into Tuesday 3rd January, and then again all day on Thursday 5th January, as described in more detail in the Weather section below.

Details of snow depths measured at various locations on the trail system are given at the foot of this posting. Note however that snow depth itself is rarely indicative of the difficulty (or otherwise) of hiking a particular trail.

With at least two further snowfalls expected in the next few days, and strong winds in the high country expected for the next week causing substantial daily drifting of snow, much of the trail system will remain largely obscured by light to moderate snow until the second week of January. Consequently cautious navigation is recommended everywhere.

Snow depths are currently excellent for snowshoeing everywhere above about 8000 ft, potentially lower in places. This will continue to be the case for at least a week, given fresh snowfall expected. With compaction of the trails in the second week of January, snowshoes may steadily become less useful, however they will remain valuable for off-trail travel in the high country for the foreseeable future.

Spikes are currently useful throughout the trail system above about 5000 ft, potentially lower in places. They are not however required, depending upon your comfort level hiking on shallow variable snow, mixed with slushy and icy patches. Spikes will likely become more increasingly useful over the next few days and weeks as established trails become consolidated by hiker traffic and undergo freeze-thaw cycles. Spikes tend to be especially useful for descending trails.

As of the afternoon of Sunday 1st, the only tracks that I saw and that are known to be in place are my snowshoe track between Humber Park and San Jacinto Peak (using Devil’s Slide, Wellman, and Peak trails). There were posthole tracks heading south from Saddle Junction toward Chinquapin Flat. There is already a moderately traveled posthole track on Devil’s Slide Trail, and I was surprised to find that below 7000 ft some of the trail was already slushy simply due to relatively warm air temperatures as there was no direct sun.

Some general comments on snow/ice conditions. Time of day, temperature, and sun exposure all have significant impacts on the nature of the snow, in turn changing the conditions underfoot, and hence both the hiking difficulty and the preferred traction device (if any). These impacts are especially striking in Southern California mountains, where the sun is relatively potent even in midwinter and where even on the coldest days temperatures at mid elevations may fluctuate either side of freezing. A rapidly warming montane climate, with changes especially striking at high elevation, is exacerbating all of these issues.

Currently the snow is relatively powdery and benign; this will steadily change over the next few days and weeks. Note that temperatures fluctuating either side of freezing are forecast for both mid and upper elevations starting in a few days time. Steady melting of snow, especially on sun-exposed slopes, and freeze-thaw cycles will combine to change trail conditions and potentially the preferred equipment for the terrain.

Hikers should be prepared for temperatures below freezing in the high country, and far below freezing when considering wind chill effects (see below for my recent weather observations from San Jacinto Peak).

Currently the USFS gate at Humber Park is closed. When the gate is closed there are still nine legal parking spaces this side of the locked gate (which still require an Adventure Pass or equivalent to be displayed). Vehicles not parked in these spaces may be ticketed and/or towed. If there are “Road Closed” signs further down – as was often the case last winter at weekends and holidays – then those nine spaces are also unavailable for legal parking.

South Ridge Road (5S11) is also currently closed to vehicle traffic.

Dark Canyon Road (4S02, the access to Seven Pines Trail) and Santa Rosa Truck Trail (7S02) closed to vehicle traffic for the season on 7th November 2022. Black Mountain Road also closed on 7th November to vehicle traffic at the gate 1.7 miles up from Highway 243. Forest Service campgrounds at Boulder Basin, Marion Mountain, and Fern Basin are closed for the season. The State Park Stone Creek campground is also closed.

WEATHER

Conditions remain very unsettled for the first week of January. At least two further minor storm systems are forecast, overnight on Monday 2nd into Tuesday 3rd, and then again all day on Thursday 5th. These storms are each expected to produce a further 4-6 inches of snow. However the Tuesday storm is forecast to be much colder, with a freeze level dropping to 5000 ft, with several of inches of snow therefore possible at the elevation of Idyllwild. The high country may be above the cloud for some of that storm, as only 2-3 inches are forecast for the high country. The Thursday system will be significantly warmer, with a freeze level not dropping below about 7000 ft. Precipitation at the elevation of Idyllwild should therefore be rain (0.5-0.7 inch currently forecast), which may therefore largely melt and remove the snow that had fallen earlier in the week at that elevation.

At San Jacinto Peak (10,810ft/3295m) on Sunday 1st January 2023 at 0830 the air temperature was 17.9°F (-8°C), with a windchill temperature of -2.3°F (-19°C), 100% relative humidity, and a sharp WSW wind sustained at 11 mph gusting to 21.1 mph.

At the Peak on Saturday 31st December 2022 at 1650 the air temperature was 24.9°F (-4°C), with a windchill temperature of 4.8°F (-15°C), 62% relative humidity, and a bitter WSW wind sustained at 18 mph gusting to 30.1 mph.

At the Peak on Thursday 29th December 2022 at 0910 the air temperature was 25.8°F (-3°C), with a windchill temperature of 7.2°F (-14°C), 81% relative humidity, and a harsh WNW wind sustained at 12 mph gusting to 25.4 mph.

TRAIL CONDITIONS

All trails above about 5000 ft are currently lightly (or above 8000 ft, moderately) snow-covered.

Reliable tracks are in place (at least) for Devil’s Slide Trail. While my snowshoe track continues from Saddle Junctions through to San Jacinto Peak via Wellman Divide, this may rapidly become obscured by additional light snowfall and/or drifting snow from strong winds.

As discussed above, additional light snowfall on 3rd and 5th January will further complicate the trail conditions.

The 0.4 mile section of South Ridge Trail between Chinquapin Flat/PCT and Tahquitz Peak has no steps to follow through the steeply angled icy snow. Although the snow is not currently particularly deep (10-12 inches) it is heavily drifted and has an ice layer underneath the fresh powder. These icy slopes are notoriously treacherous. Currently spikes at a minimum, and ideally crampons, with an ice axe, are strongly recommended. Snowshoes are not advisable due to the angle of the icy snow.

SNOW DEPTHS measured on 1st January 2023 are as follows. The first number is the depth of fresh snow from this latest storm, followed in parentheses by the current total snow depth. Since the depths given in the previous Report, there had been very minor storms on 28th and 29th December, which added a couple of inches at the highest elevations, down to 0.5 inch at 8000 ft. However I was surprised to find almost all of this had melted by the time I hiked to San Jacinto Peak on 31st December. Note that average depth is given; due to strong winds accompanying the storm there is extensive drifting, often particularly accumulating in the trails. Conversely in some places scouring by the wind means the depths are well below the average. Altitudes are approximate.

San Jacinto Peak (10810 ft): storm total 12 inches (total depth 17-20 inches)

Wellman Divide (9700 ft): 8 inches (total 9 inches)

Annie’s Junction/approx. PCT Mile 181.8 (9070 ft): 9-10 inches (total 11-12 inches)

Long Valley (8600 ft): 8 inches (8-9 inches)

Saddle Junction/approx. PCT Mile 179.9 (8070 ft): 8 inches (8-9 inches)

Devil’s Slide trailhead at Humber Park (6550 ft): 4 inches (total 4 inches)

Idyllwild (at 5550 ft): 3.5 inches (total 3.5 inch).

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