General Bulletin for Saturday, November 30, 2019

This information was published 11/30/2019 at 7:19 AM.
New information will be issued when conditions warrant.


The Bottom Line

Due to low staffing levels, the Mount Washington Avalanche Center will be issuing General Bulletins only until January 15 regardless of snow and weather conditions. No daily avalanche forecasts will be issued and no danger ratings will be assigned to our forecast area until that time.

Recent storms and wind loading have developed snowfields capable of producing avalanches. These snowfields, and the avalanches that occur on them, will continue to grow as cold weather and wind allow snow to fall and load into the terrain. One of the five classic red flags often used to determine avalanche danger is recent avalanche activity. A human-triggered avalanche on Friday, November 29 is a good reminder that avalanches can and do occur on smaller snowfields. New snow and wind-loading are two more of these red flags. As always, make careful assessments of snow and terrain on an ongoing basis.

Danger Rating by Zone

The Tuckerman Ravine and Huntington Ravine trails are challenging climbs with significant avalanche hazard during winter. Both have been the scene of serious accidents where they pass through the steepest terrain of these Ravines. The summer Lion Head Trail remains the safer choice for accessing the summit of Mount Washington from the east. As more snow falls and avalanche paths grow on the summer Lion Head trail, the Lion Head Winter Route will become the preferred route to the summit. Using the Lion Head Winter Route too early causes significant erosion and resource damage. An ice axe and crampons are currently needed at treeline and above. The Sherburne ski trail has snow coverage to the parking lot though numerous water bars remain partly open. Most but certainly not all rocks are covered.

Ice climbs are growing in size and pockets of unstable snow between ice pitches are notorious for causing problems.  In addition to avalanche hazards, remember to take into account 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, even if you are only swept off your feet by a small avalanche.

55″ of snowfall has been recorded on the summit of Mount Washington during November. Currently, there’s about 24″ of snow on the ground at the wind-sheltered snow study plot near Hermit Lake. Over half of these snowfall totals fell during the last week of November. Though the bulk of the next winter storm, forecast for early in the first week of December, appears to be tracking to the south, you can expect enough new snow to fall in the Presidential range to increase the avalanche hazard on our growing avalanche paths. Be sure to check the MWOBS Higher Summits forecast as you plan your journey. Weather conditions change dramatically as you gain elevation so be prepared to turn back or change your objective when you observe nature’s warning signs for avalanches. Plumes of snow at ridgetops and wind blown sluffs are clear signs that slopes are being loaded and possibly primed for an avalanche.

You can keep tabs on current conditions through a number of resources included on this website or through our partners such as the Mount Washington Observatory and the National Weather Service. You’ll find hourly recorded weather data, including snow water equivalent, at the NWS here and easier to read 24 hour totals here or in chart form here. Additionally, you can check our Observations page to see photos, videos and descriptions submitted by our readers. Take a moment to submit a photo and description of what you find on the Observation page. Tagging us on Instagram also helps.

2019-11-30 printable General Bulletin

Snow Plot Information

DateHN24HN24W
(SWE)
Density (%)HSTTotalAir TT MaxT MinSkyPrecipComments
12/12/19
05:00
1 CM 0.2 MM1CM55 CM-12.0 C-7.0 C-12.0 COvercastNo precipitation
12/11/19
05:00
Trace 9.9 MMTrace55 CM-10.0 C4.0 C-10.0 COvercastNo precipitation
12/10/19
05:15
0 CM 23.0 MM0CM59 CM2.5 C2.5 C-2.0 COvercastRain
12/09/19
05:30
1 CM 2.0 MM 20%NC71 CM0.0 C1.0 C-12.5 COvercastSnow
12/08/19
05:45
2 CM 0.8 MM 5%7CM73 CM-12.5 C-10.0 C-14.0 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
05/30/1946 F36 F 0 in 0 in27.9 MPH55 MPH

290 (WNW)

05/29/1947 F33 F 0 in 0 in20 MPH48 MPH

290 (WNW)

05/28/1934 F28 F .71 in 3.7 in20 MPH48 MPH

290 (WNW)

05/27/1940 F27 FTrace 0 in38.9 MPH68 MPH

300 (WNW)

05/26/1948 F39 F .77 in 0 in48.7 MPH75 MPH

290 (WNW)

05/25/1947 F31 F .42 in 0 in17.7 MPH63 MPH

240 (WSW)

05/24/1942 F32 F .66 in 0 in44.8 MPH105 MPH

05/23/1944 F30 F .16 in 0 in26.8 MPH71 MPH

270 (W)

05/22/1934 F21 F 0 in 0 in36.2 MPH115 MPH

330 (NNW)

05/21/1934 F23 F .57 in 1.9 in73 MPH135 MPH

330 (NNW)

05/20/1951 F33 F 0.57 in 0.0 in48 MPH82 MPH

250 (WSW)

05/19/1951 F34 F .6 in 0 in34.2 MPH66 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 11/30/2019 at 7:19 AM.

Frank Carus
USDA Forest Service
White Mountain National Forest