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ADVANCED OBSERVATION FORM
 Start Date: 04.17.19 End Date: 04.17.19
 Drainage/Route:  Boulder Creek - Boulder Peak (South and West bowls) Observed Terrain:  6600’-10,700’ E-S-W Zone/Region:  Smoky & Boulder Mountains
WEATHER OBSERVATIONS
 HN24: HST: Sky: CLR Precip: Temps: 26-50F
 Ridgeline Wind: Strong and Steady from the W
 Blowing Snow: L Snow Available for Transport: Small amounts
AVALANCHE OBSERVATIONS
 No. Location Date Size Type Trigger Aspect Elevation Comments
 1 Boulder Peak Yesterday 3.5 HS ASu S 10,750’ Slide ran full length of path to valley floor Slide ran to valley floor
 Comments: Slide released while skier was boot packing back down from the summit of Boulder Peak, broke on windslab and propagated out before stepping down to basal facets. Crown height was 2-3’. Did not investigate bed surface in start zone after slide ran.
AVALANCHE PROBLEM ASSESSMENT
Avalanche Characteristics
Character/Avalanche Problem:
Wind Slab

Layer/Depth:
30-50cm

Likelihood of Triggering
Sensitivity:
Touchy

Spatial Distribution:
Specific
Where did you find this problem?
  Primary Concern Comments: Observed above 10,000’
 
Avalanche Characteristics
Character/Avalanche Problem:
Persistent Slab

Layer/Depth:
40cm to ground

Likelihood of Triggering
Sensitivity:
Stubborn

Spatial Distribution:
Widespread
Where did you find this problem?
  Problem 2 Comments: 
 Comments: Snow below MF crust at 30-40cm was faceted and bottomless along ridgelines and in areas with thinner snowpack.
STABILITY TESTS
 Stability Test Results: Not performed
SNOW STABILITY
 Snow Stability Rating for your observed area: Fair Confidence: MODERATE Trend: Steady
 Comments (aspects and elevations of instability, etc): Snow stability below 10,000’ was good with a solid MF crust and behaved as a “spring” snow pack with warming due to solar exposure as the primary concern. Above 10,000’ and especially in rocky areas the snowpack was thinner and much more of a midwinter snowpack with snow (deposited and transported) on a MF crust over faceted snow that went all the way to the ground.
BOTTOM LINE
 Comments: Snow stability seemed good until higher elevations where the character of the snow and the stability changed rapidly. The lack of signs of instability prior to the release of the slide was disconcerting. Wind slabs were visible but did not seem reactive. The PWL that was present this winter appears to be still in evidence and is increasingly reactive in areas with a thinner snowpack.
FILE ATTACHMENTS

1082FA0D-A767-4FF9-A0F2-C44AF796CFAC.jpeg
Crown is visible along ridgeline

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Deposition pile in valley floor