Avalanche Forecast for Saturday, January 19, 2019

This forecast was published 01/19/2019 at 7:21 AM.
A new forecast will be issued tomorrow.


This is an archived avalanche forecast and expired on 01/19/2019 at midnight.

The Bottom Line

The coming winter storm will create conditions that might meet avalanche warning criteria, but today is a different story. Small pockets of wind slab formed last night add some spice to generally stable conditions. You could trigger one of these new small slabs, but they should be easy to avoid. All forecast areas have LOW avalanche danger. Widespread areas of hard snow will make long sliding falls as much of a concern in your travel this morning, and consider that visibility will generally deteriorate through the day. Using normal caution for avalanche terrain and remembering that Low doesn’t mean no avalanche danger should make today the safest conditions of the holiday weekend.


Forecast Area

The USDA  Forest Service Mount Washington Avalanche Center has issued a backcountry avalanche watch for the Presidential Range.  Avalanche Watch criteria may also be met in other areas outside those forecast by the avalanche center. This avalanche watch does not apply to operating ski areas.

Avalanche danger will increase through Sunday and Monday,  January 20-21, 2019 creating dangerous avalanche conditions. Widespread natural avalanche activity will be possible, especially on Monday, January 21.

A potent winter storm arrives this evening  and will continue through Sunday, January 20. Expected heavy snowfall will combine with strong winds to create unstable conditions. Strong NW winds on Monday, January 21 will create conditions for very large avalanches.

Avalanche Safety Information Study

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Mountain Weather

Around 1” of new snow yesterday was affected by westerly wind that increased to the 60-80 mph range for much of last night. Wind is currently diminishing and will continue to do so through daylight hours. High temperature should be a few degrees colder than yesterday’s summit high of 10F, with summit temperatures in the lower single digits. Increasing cloud cover today will ultimately bring heavy snow that will begin falling in light amounts this afternoon and intensify nearer to midnight. Heavy snow should continue continue through most of tomorrow, tapering to lighter precipitation rates by evening. Snow totals currently look to be around 15” but could be more. Through the snow storm, wind is forecast to shift from SW at dawn tomorrow through E and NE by afternoon, ultimately blowing from the NW by tomorrow night. Wind speeds will increase with this shift, from 25 mph tonight to around 50 mph or stronger by tomorrow night.

Primary Avalanche Problem – Wind Slab

Wind Slab




New wind slabs formed overnight should be reactive to a human trigger but small in size. While either of relatively little concern or easily avoidable, remember that small avalanches in the wrong place can be a big deal. We expect you’ll find these isolated pockets on the eastern half of the compass rose.

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

A mixed bag of upper snowpack and surface conditions precede the inbound winter storm. Most of our avalanche start zones have a relatively smooth snow surface, with a few exceptions of heavily wind textured snow and less developed paths on the west side. Snow and wind last week created this mix of layered wind slabs which vary in density and are generally quite hard and unreactive. Pockets of softer wind slab do exist in the terrain, both in the form of reactive but small new wind slabs and more stubborn, older pockets. For Sunday and Monday, consider our current mix of relatively smooth bed surfaces on thick hard slabs, some potential for an avalanche to step down to deeper layers in softer pockets, and that the December 22 crust is still present at or near the surface in some scoured locations.

Additional Concerns

The Sherburne and Gulf of Slides ski trails are snow covered to Pinkham Notch.

Snow Plot Information

Density (%)HSTTotalAir TT MaxT MinSkyPrecipComments
0 CMTrace 0CM0 CM8.0 C11.0 C0.5 CBrokenNo precipitation
0 CM 0.0 MM0CM0 CM7.5 C7.5 C1.0 CScatteredNo precipitation
0 CM 22.3 MM0CM0 CM1.5 C4.0 C0.0 COvercastNo precipitation
0 CM 0.0 MM0CM0 CM0.5 C11.0 C0.5 CClearNo precipitation
0 CM 0.0 MM0CM10 CM8.0 C15.5 C8.0 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 01/19/2019 at 7:21 AM.

Ryan Matz, Snow Ranger
USDA Forest Service
White Mountain National Forest