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PROFESSIONAL OBSERVATION FORM
 Start Date: 02.26.19 Name: Davis Operation: SAC
 Drainage/Route:  HWY 75 roadside from Greenhorn to Hailey Observed Terrain:   Zone/Region:  Wood River Valley
WEATHER OBSERVATIONS
 HN24: HST: Sky: Precip: Temps:
 Ridgeline Wind:
 Blowing Snow: Snow Available for Transport:
AVALANCHE OBSERVATIONS
 No. Location Date Size Type Trigger Aspect Elevation Comments
 1 North of East Fork Rd. 2 SS N W 5800'
 1 Greenhorn Fire Station 2 SS N W 5800' Far north end of the hill behind the fire station. This pocket was not connected to the rest.
 1-3? Greenhorn Fire Station Yesterday 3 SS N W 5800' This slide or slides occurred just before 11 PM on (2/25). Debris in the river was up to 30' deep. The avalanche jumped the bank on the far side sending debris onto the roof of one home and the second story balcony of another. Both homes suffered broken windows. One of these slides also damaged the railroad bridge and sent debris within 100' of HWY 75.
 1 Greenhorn Fire Station Today 2 SS N W 6000' This slide ran while we were on site at about 1115 AM. A wind-loaded pocket of hangfire on the south end of the formation behind the fire station and closest to the railroad bridge.
 1 Golden Eagle 1.5 SS N NW 5800' Storm slab in the usual location above Golden Eagle on the south side of Greenhorn Rd (west side of HWY 75).
 Several E. Face of Carbonate Yesterday 2 N Up to D2. At least one crossed the river and struck an avalanche engineered home on River Trail at 9 PM.
 Several E. Face of Della 2 N 5800' Did not block the river or reach the homes.
 1 Hulen Meadows Today N W Crossed and blocked HWY 75 at about 1115 AM.
 1 Alexander Ross Today U Crossed and blocked HWY 75.
 1 Alturas Elementary Today U W Plow truck triggered? Driver reported feeling the truck move sideways. Sounded relatively small, limited details.
 Comments: It appeared that most of the storm slabs observed from Greenhorn and south involved only the new snow and were clustered right around the rain/heavy-wet-snow line. Ben reported this same pattern all along the HWY to the north toward Ketchum. Things will get really wild if slides start to release deeper or if tonights/tomorrows storm brings in rising rain/snow lines and more rain. Pictures of home 1 are used with owners permission.
STABILITY TESTS
 Stability Test Results:
SNOW STABILITY
 Snow Stability Rating for your observed area: Confidence: Trend:
FILE ATTACHMENTS

190226_Greenhorn_03.jpg
Debris across the river toward house 1. This debris was nearly 30' deep before the river undercut it and carried it away.

190226_Greenhorn_06.jpg
Back of house 1. The doors in the right of the frame were blown into the home.

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One of the back windows in home 1.

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Doors broken in on home 1.

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Debris wrapped around home 1 and broke through this window.

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Crown and debris above home 2.

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Slide on the south end of the formation that damaged the bridge. A smaller slide from a little higher up the slope came down today and impacted the same zone.

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Bridge damage.