Observation type - Pro
Snowpack & Avalanches 

Observer
Allen Giernet 

Keep me anonymous if published
no

Location (general area)
Angeles Nat Forest San Gabriels 

Latitude

Longitude

Date (yyyymmdd)
20240406

Time
8am - 4pm

Road conditions to area
clear 

Temperature
28F - 35F

Sky
clear (no clouds)
Sky began clear and became overcast by 2pm

Wind speed
Light (1-16mph Flags/twigs in motion) 
wind began calm and became light in the late morning 

Wind direction
N

Wind direction in degrees

Slope aspect
Northerly to Southerly aspects observed through the day 

Aspect in degrees
22°

Slope angle
32°

Elevation
9070'

Snow depth
255cm / 8.3' - variable depending on elevation and aspect 

Boot/ Ski penetration
25cm 

Precipitation
None
Activity, recent avalanches
yes

Brief description
several Small Dry loose triggered on descent D.5 - 1 Northerly aspects in steeper terrain. Numerous small wet loose at lower elevations NE to NW aspects. No naturals observed other than old debris prior to last storm

Whumphing noises, shooting cracks. collapsing
no

Rapid warming
yes

Obvious avalanche path
yes

Terrain trap
yes

Comment
Snow covering roof tops and and trace snow on sides of 14 Fwy began west of Vasquez rocks on drive out 6:45am 

8am snow blanket ground thinly at 3700’
AT near freezing
Sk clr
And C


9:15 5,833’
HS 1.4cm -7.5 cm
Trees just starting to shed snow
Sky clr
Wnd C


6500’
10a
Sk cle
Wnd C
Dust on crust & scree 2-7cm steep NE
Noted rock fall began


Pics of road cuts avi debri 1 drainage east side of Baden N
2 Baden N
3 drainage west side of Baden N


10:40a N 7,011”
HA 45cm
HNS 15cm
On Mfc
Quickly slope got steep crust got firm and only 15cm of snow made me glad I had ski crampons


Highly recommend crampons for climbers and ski crampons for sliders. Kicking steps is possible but a long way. Also no amount of skin was could save my skins from flopping after they accidentally got dipped in the creek. But wax your skins for sure.


11:15 the road I skinned up was now devoid of snow


11:45 N 16 deg 7566’
HS 50cm
HNS 14cm
Variable surface from light pow to wind scoured crust and snow becoming warm and wet on surface in sun.
Angle 20deg
AT 0 C
W- SSE -L


8000’ wind loaded areas on ridge up to 90cm


2pm
Sk act
W L NNE

Also noted heavy timing on trees towards S at ridge
Next pic 2:11 low clip yes came op to ridge from south. White out to 40 yards vis its stopping at ridge and hoping it will stay there.

Pit 1 S 9100’ just below ridge
HS 40cm -37cm
2 crusts top is faint P- to 1F 37cm
middle is 17-20cm 1F to P crumbly
Bottom is solid ice not sure how close to ground ?
Pf 20cm

3:11p pit 2
Sk ovc
W-L-N
Asp NNE 22deg
Elev 9070’ just below ridge
AT - -2C
Angl- 32deg
Lat/lon see pic

4pm on descent
Steeper slope angles dry loose avalanches were easily triggered D1 begin around 8500’

At lower elevation approximately 7800’ noted numerous wet loose avalanche on WNW aspects

Continuing down to lower elevations a crust develop from the refreezing early warm snow surfaces.

Near 7000’ noted numerous wet loose releases from rocks and tree snow dropping on NE-N-NW aspects.

Overall the day became much warmer than forecast with temperatures up to 2C above 8000’ clouds developed in the afternoon, heavy low clouds rolled in in the south side of the ridge around 2pm and snow surface on that aspect became fairly moist. By 2:30pm the clouds spread over to the N but remained high with ovc skies. Temperatures began to fall to below freezing near 9100’. Poor bonding to surface crust at elevations was noted although actual avalanche release and running down slope was only noted on steeper terrain. The crust was very firm at lower elevations below 8,000’ and became thinner and less notable as elevation increased. No wind slabs were observed near the ridge although significant signs of wind transported was. Winds were most likely high enough to cause saltation rather than transport most of the time. Fairly large cornices were noted all along the ridge but were solid at this time. Also wind transport had packed snow into the overhanging (N) side of many cornices.

Variable conditions were not on the ascent and descent crampons would be advised and if skinning skin wax also due to warming snow surfaces at lower elevation. From the sign of wet loose releases on Northern aspects it will be safe to assume wet loose avalanches will become more numerous and larger with the warmer expected over the next few days until the snow pack can adjust and much of the new snow either sheds or begins to consolidate to the old snow surface.

Publish this observation
Yes I would like this observation Published

Active small Wet Loose activity noted around 4 pm

Pit profile North