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PROFESSIONAL OBSERVATION FORM
 Start Date: 04.09.19 Name: Lundy Operation: SAC
 Drainage/Route:  Driving: Stanley to Galena Summit Observed Terrain:   Zone/Region:  Sawtooth Mountains
WEATHER OBSERVATIONS
 HN24: HST: Sky: Precip: Temps:
 Ridgeline Wind:
 Blowing Snow: Snow Available for Transport:
 Comments: A mix of OVC and BKN skies. A few flurries at the highway level. Breezy even in valley, with winds atop Galena Summit moving small amounts of snow into small drifts on the side of the road.

Based on rollerballs visible on north aspects, it looks to have rained (at least briefly) to around 9200-9400'. Snow visible in the trees above 8200'. Significantly more HST at the north end of the Sawtooths than at the south end or in the Salmon Headwaters area. At the north end of the Sawtooths, there appeared to be significant accumulations above around 8400' with snow in the trees and plastered to cliffs.
AVALANCHE OBSERVATIONS
 No. Location Date Size Type Trigger Aspect Elevation Comments
 Many Sawtooths & Beaver Creek Yesterday 2 SS N 9400-10000 Numerous slabs observed at upper elevations, primarily on N-NE-E aspects. Most were above the rain line. Some propagated fairly wide. A couple of the lower ones (near 9400') may have been rain-induced. Also evidence of midstorm activity. Unsure if they're involving the storm snow or older snow layers. See photos.
 Many Marshall & Meadow Bowl Yesterday 2 WL N SE 9500 Numerous small to medium WL within the storm snow. See photo.
 1 Marshall Yesterday 2.5 U N NE 9700 Larger avalanche originated in cliffs above meadow bowl and ran a significant distance.
 Comments: Light was pretty flat, but had decent visibility of the north end of the Sawtooths from Williams to McGown and the south end near McDonald and Cabin Creek. Decent viz of the Salmon Headwaters and the Boulders from Galena Summit.

Widespread storm-related slab avalanches in the Sawtooths and in Beaver Creek. Remarkably few WL at mid elevations below the rain line. Most WL was at upper elevations within the storm snow.
STABILITY TESTS
 Stability Test Results:
SNOW STABILITY
 Snow Stability Rating for your observed area: Confidence: Trend:
BOTTOM LINE
 Comments: Hard to know nature of observed avalanche activity without visiting the crowns and having a better handle on storm snow depth. Based on Scotty's observations from Beaver Creek today, several of these slabs likely broke on older weak layers (early March?) or on wet layers (especially the ones below about 9500').
FILE ATTACHMENTS

190409_meadow_cr_SE_9500.jpg
Wet loose activity within the storm snow. A few may have released as slabs. A larger avalanche originated in cliffs on the left side of the photo.

190407_beaver_cr_NE_10000-9400.jpg
Slabs in Beaver Creek ranging from 9400-10000'

190409_mcgown_plastered.jpg
More new snow fell at the north end of the Sawtooths

190409_beaver_cr_NE_9200.jpg
Slabs in Beaver Creek at around 9200'. Possibly rain induced.

190409_cabin_cr_E_9800.jpg
Slabs, wet loose, and roller balls in Cabin Creek

190409_McDonald_NE_9600.jpg
Slab near McDonald Creek. Flank visible running downslope in the middle of the photo.

190409_cabin_cr_NE_9600.jpg
Wider slab at the head of Cabin Creek. Midstorm slabs evident in lower left side of photo