Friday January 4, 2019

Sunday January 6, 2019
Saturday January 5, 2019
Friday January 4, 2019
Confidence: Low - high degree of variability between both snowfall and rainfall amounts in western and eastern zones of the forecast area.

Main Concerns

Loose Wet, Storm Slab - view Avalanche Problems for detailed information.

Travel & Terrain Advice

Utilize only non avalanche or simple terrain. Seek alternatives to steep terrain and expect even small loose wet avalanches to have to strength to push a mountain traveler into and over terrain traps. Large storm slab avalanches have the potential to run full path, be aware of your positioning in terrain and avoid exposure in avalanche run outs.

Avalanche Summary

Avalanche control teams at Mount Washington reported widespread loose wet natural avalanches on all aspects and elevations treeline and below.

Avalanche Problems

Loose Wet

Found at all elevations and on all aspects, loose wet avalanches even when small can be strong enough to push a mountain traveler into and over terrain traps. Expect on steep terrain these problems to gain mass and could be greater than size two in destructive size.

Storm Slab

At elevations above 1700 meters in the alpine storm slabs have formed. Expect these avalanches to be present on all aspects and if triggered have the potential to be greater than size three in destructive size.

Snowpack Summary

Past snowfall and a mix of both snowfall and rain dependent on elevation was then followed by moderate to heavy rain fall. All combined with strong south wind. The upper snow pack is wet to moist and currently unconsolidated, expect above 1700-1800 meters to find heavy and deep snowfall accumulations. The snow pack has seen rapid input of both snow and rain and requires cooling and time for settlement and bonding to begin.

Snowpack Details

Surface unconsolidated and wet
Upperunconsolidated and wet
Midwell settled
Lowerwell settled

Past Weather

Continued heavy precipitation, rising freezing levels and strong south western winds persisted, over the past 48 hours. Freezing levels breached the 1700 meter level in many areas and up to 40 mm of precipitation in the form of rain fell upon the snow pack.

Weather Forecast

A low pressure is stalled to the west of the region and will continue to bring to the forecast area, heavy precipitation, strong winds, and high freezing levels. Beginning mid day Friday, expect this storm system to begin its exodus with temps and freezing levels returning to conditions favorable for snowfall.

FRIDAY 30-50 mm of precipitation with freezing levels descending late afternoon to around 1200 m. Winds strong from the South.

SATURDAY 10-20 cm of accumulation with freezing levels around 1000 m . Winds moderate from the East North East.

SUNDAY 5-10 cm of accumulation with freezing levels around 200 m. Winds Moderate from the South West.

Posted on Friday January 4, 2019 by Jesse Percival

Past Bulletins