General Bulletin for Wednesday, November 21, 2018

This information was published 11/21/2018 at 7:00 AM.
A new bulletin will be issued when conditions warrant.


The Bottom Line

General Bulletins are issued when unstable snow may exist within our forecast areas but before 5 scale avalanche advisories begin. Please remember that avalanches can occur before 5-scale avalanche forecasts are issued. This

Terrain around Mount Washington continues to collect snow with snowfields increasing in size. Some avalanche paths are growing rapidly while others still continue to harbor more rocks and brush than snow. While snowfields are growing, most avalanche paths are not quite fully developed. Traditional start zones have not yet filled in, but smaller avalanches are occurring in areas that have enough snow. These same areas are the places getting attention from skiers and climbers. With the early season stoke in high effect at the moment and many people trying to ski and climb, it’s important to remember the basics: travel one at a time and make use of safe zones, avoid skiing or climbing under or above another party, and bring your avalanche rescue gear.

 

Danger Rating

Over that last four days, the summit of Mount Washington recorded over 15″ of new snow. The 4″ that fell yesterday arrived on lighter winds and will be subject to strong W and NW winds through the remainder of the week and into the weekend. In addition, another 2-4″ is forecast for higher elevations Wednesday afternoon. Strong wind should continue to transport any available snow to the east side of the mountain range, further developing snowfields in lee areas of steep, extreme terrain. Bed surfaces are currently a mixed bag with terrain appearing to change on a daily basis as cliffs and ice bulges turn into snowfields. Over the course of the holiday, the weather forecast looks clear and windy, with the big story being the cold. Be prepared for mid-winter conditions if venturing into avalanche terrain with equipment to make snowpack assessments and to be self-reliant should the need arise. Respect small pockets of potentially unstable snow which have historically been the culprit of early season avalanche accidents on both ice climbs and larger snow slopes. In addition to avalanche hazards, be mindful of other early season hazards that exist in the terrain:

  • Rocks, trees and bushes lurk in the snow and in the fall line. Skiing or sliding into obstacles can ruin your day or worse. New snow may just barely cover a season ending stump or boulder.
  • Terrain traps and cliffs make burial and significant injury a real possibility, heightening the consequences of a fall or small avalanche.
  • Long sliding falls are a threat despite the appearance of new, soft snow on your approach. Wind can easily scour parts of your climb or hike down to a hard bed surface. What you thought would be a mellow snow climb can turn into something much more exciting.  Consider using a rope in third class terrain or sooner than normal due to the slick surface.

The summer Lion Head Trail remains a preferred east side route to the summit over the Tuckerman and Huntington Ravine Trails, though watch for our recommendation towards the Winter Route that will come with additional snowpack development.

Snow Plot Information

DateHN24HN24W
(SWE)
Density (%)HSTTotalAir TT MaxT MinSkyPrecipComments
04/13/20
06:15
0 CM 0.1 MM0CM206 CM-3.5 C7.5 C-7.0 COvercastRain
04/12/20
06:20
Trace 1.8 MMTrace216 CM-7.0 C-4.0 C-7.0 CFewNo precipitation
04/11/20
06:20
14 CM 23.1 MM 14%62CM222 CM-8.0 C-6.0 C-8.0 COvercastNo precipitation
04/10/20
06:30
53 CM 49.5 MM 12%NC200 CM-6.0 C-2.0 C-6.5 COvercastSnowView
04/09/20
06:25
0 CM 0.0 MM0CM158 CM-1.0 C8.0 C-4.5 CClearNo precipitation

Avalanche Log and Summit Weather

Thank you Mount Washington Observatory for providing daily weather data from the summit of Mount Washington.

DateMax TempMin TempTotal (SWE)24H Snow & IceWind AvgWind Fastest MileFastest Mile DirAvalanche Activity
05/25/2054 F46 F 0.0 in 0.0 in18.7 MPH44 MPH

260 (W)

05/24/2054 F40 F 8.3 in 21 in8.3 MPH21 MPH

280 (W)

05/23/2055 F43 F 0.0 in 0.0 in15 MPH45 MPH

300 (WNW)

05/22/2055 F40 F 0.0 in 0.0 in37.4 MPH67 MPH

290 (WNW)

05/21/2053 F38 F 0.0 in 0.0 in29.4 MPH59 MPH

280 (W)

05/20/2050 F34 F 0.0 in 0.0 in29.4 MPH59 MPH

280 (W)

05/19/2041 F27 F 0.0 in 0.0 in15.3 MPH36 MPH

100 (E)

05/19/2050 F34 F 0.0 in 0.0 in11.4 MPH25 MPH

30 (NNE)

05/18/2045 F30 F 0.0 in 0.0 in14.7 MPH36 MPH

70 (ENE)

05/17/2040 F30 F 0.0 in 0.0 in17 MPH35 MPH

270 (W)

05/16/2037 F28 F .16 in 0.0 in38.8 MPH101 MPH

310 (NW)

05/15/2042 F32 F .95 inTrace 31.5 MPH95 MPH

250 (WSW)

Please Remember:

Safe travel in avalanche terrain requires training and experience. This forecast is just one tool to help you make your own decisions in avalanche terrain. You control your own risk by choosing where, when, and how you travel.

Avalanche danger may change when actual weather differs from the higher summits forecast.

For more information contact the US Forest Service Snow Rangers, AMC visitor services staff at the Pinkham Notch Visitor Center, or the caretakers at Hermit Lake Shelters or seasonally at the Harvard Cabin (generally December 1 through March 31). The Mount Washington Ski Patrol is also available on spring weekends.

Posted 11/21/2018 at 7:00 AM.

Helon Hoffer Snow Ranger
USDA Forest Service
White Mountain National Forest