Avalanche Forecast for Sunday, January 13, 2019

This forecast was published 01/13/2019 at 6:56 AM.
A new forecast will be issued tomorrow.

The Mount Washington Avalanche Center will no longer issue daily avalanche forecasts for the 2018/19 season. Read more

The Mount Washington Avalanche Center will no longer issue daily avalanche forecasts for the 2018/19 season. Instead, we will post an updated General Bulletin as needed, in case of significant snow or weather events that might vary from the typical daily changes that come with spring weather. We will also keep you informed about the official closure of the portion of the Tuckerman Ravine Trail from Lunch Rocks through the Lip and Headwall as well as the switch from the Lion Head Winter Route to the summer trail. Observations from the field will continue to be a valuable resource, so please keep submitting photos, videos and observations here and we will do the same. Check the Forecast page for update on Sherburne Trail closures, which are imminent as spring snowmelt continues.

The switch to a General Bulletin does NOT mean that the mountains are now a safe place to ski. The hazards which emerge in the spring are significant and require careful assessment and strategic management. If you have never skied Tuckerman, peruse our Incidents and Accidents page for spring related incidents involving avalanches, long sliding falls, icefall, crevasse and moat falls, and other incidents related to diurnal changes in the snowpack. These will help you understand and plan for these hazards.

The Bottom Line

High wind speeds have deposited wind slabs that will be stubborn to human triggers today, but could produce a large avalanche. Hard wind slabs like those that exist in much of our terrain are difficult to evaluate for stability, but can be easily navigated by avoidance. Today’s avalanche problem often produces no avalanches until an unlucky skier or climber ventures to find the particular weak spot in the slab. The potential size and destructiveness of an avalanche today is keeping our danger ratings elevated at MODERATE. Locations with a LOW rating (Tuckerman’s Left Side and Boott Spur as well as Huntington’s Northern Gullies) do contain snow that could produce an avalanche and will still require careful terrain selection.

2019-01-13 Printable

Danger Rating by Zone

Mountain Weather

The last recorded snowfall in our terrain was Thursday evening. Since that time, NW winds blew in the 70-100 mph range until midday yesterday. A sharp drop in wind speed took place overnight with wind currently WNW 15mph. Today, wind will be light and variable with some high level clouds. Expect sunshine for much of the day with temperatures on the summits cresting at 10F.  No new snow is forecast tonight or tomorrow.

Primary Avalanche Problem – Wind Slab

Wind Slab




Wind slab exists primarily on the eastern half of the compass. Most of these formed on high wind speeds after a widespread avalanche cycle Wednesday night and Thursday. Most existing wind slabs will be stubborn to human triggers. Areas with a large upwind fetch at mid-elevations have the potential to produce a large avalanche should you find the thin spot of the slab. Lower elevations or wind-sheltered locations may harbor softer pockets of wind slab that may be possible to produce an avalanche, but the overall size will be smaller.

What is a Windslab Avalanche?

  Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

Snowpack and Avalanche Discussion

The effect of Mount Washington’s notorious wind combined with last week’s 26” of snow should finally reveal itself today as blowing snow and fog finally subside. Ravines with a larger upwind fetch such as Tuckerman and the Gulf of Slides both saw significant avalanche activity, likely Wednesday into Thursday, while other ravines with a similar aspect but smaller fetch saw much less loading of wind transported snow. Wind slabs that remain in east-facing terrain will be variable in size and distribution due to terrain, the timing of recent avalanche cycles, and reloading. Making good observations of distribution while moving in the field and basing travel decisions off this will go much further than conducting stability tests while in the avalanche problem today.

Debris below Hillman’s Highway. Photo taken Friday, January 11.

Avalanche debris at base of Gully #1 in Gulf of Slides. Photo taken Saturday, January 12.

Additional Concerns

The Sherburne and Gulf of Slides ski trails are snow covered to Pinkham Notch. Thanks to those who submitted observations on our website. These are invaluable to the avalanche center and we hope to see more submissions as the season progresses.

Avalanche Safety Information Study

Please contribute to the effort to improve backcountry avalanche forecasts! Researchers in Canada devised a study to better understand how we communicate the avalanche risk, and we need your help. Please fill out this survey. It will take a few minutes, but it will help us as we work on new ways to give you the most important avalanche information.

Snow Plot Information

Density (%)HSTTotalAir TT MaxT MinSkyPrecipComments
Trace 6.2 MMTrace60 CM0.5 C2.0 C-1.0 CClearNo precipitationView
0 CM 4.2 MM0CM60 CM2.0 C15.0 C2.0 COvercastNo precipitation
0 CM 20.4 MM0CM68 CM11.0 C12.0 C3.5 CObscuredNo precipitation
0 CM 0.0 MM0CM72 CM4.0 C6.0 C2.0 COvercastNo precipitation
0 CM 7.6 MM0CM80 CM1.0 C6.0 C1.0 COvercastNo precipitation

Avalanche Log and Summit Weather

Daily Observations

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
05/21/1934 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)

05/18/1934 F26 F 0.06 in 0.5 in39 MPH74 MPH

300 (WNW)

05/17/1940 F28 F .22 in .05 in37 MPH81 MPH

300 (WNW)

05/16/1932 F25 F .03 in 04 in22.8 MPH40 MPH

310 (NW)

05/15/1926 F20 F .05 in .4 in32.1 MPH67 MPH

330 (NNW)

05/14/1928 F17 F .2 in 2 in19.1 MPH57 MPH

100 (E)

05/13/1928 F19 F .07 in 0.9 in34.6 MPH67 MPH

100 (E)

05/12/1931 F17 F 0 in 0 in20.5 MPH47 MPH

330 (NNW)

05/11/1932 F18 F .1 in 0 in53.6 MPH84 MPH

300 (WNW)

05/10/1944 F27 F .85 in 0 in50.1 MPH88 MPH

220 (SW)

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 01/13/2019 at 6:56 AM.

Helon Hoffer
USDA Forest Service
White Mountain National Forest