Avalanche Forecast for Monday, February 3, 2020

This information was published 02/03/2020 at 7:19 AM.
A new forecast will be issued tomorrow.

NOT THE CURRENT FORECAST

This is an archived avalanche forecast and expired on 02/03/2020 at midnight.


The Bottom Line

Human triggered avalanches are possible today where wind will combine with new snow, and possibly existing snow above treeline, to form new wind slabs.  You are most likely to encounter this avalanche problem on steep slopes and cross loaded gullies in eastern ravines above 3500’ elevations. Evaluate snow carefully as you move through the terrain. Blowing snow will make identifying new wind slabs challenging from a distance. Today’s hazard rating is MODERATE.

2020-2-3 Printable Forecast


Mountain Weather

Yesterday, 0.2” of snow was recorded on the summit of Mt. Washington with a trace recorded at Hermit Lake. North west wind remained fairly steady during daylight hours at 15-20 mph. Temperatures hovered around 10 F. 

Today, 1 – 3” of snow is forecast. Higher intensity snow showers are more likely in the afternoon hours. West wind at 60-80mph and temperatures in the lower teens F.  Chance for a trace to 1” of snow overnight.

Tomorrow, in the clouds with snow showers accumulating to 1-2”. Temperatures in the lower 20sF and west wind 35-50mph.

Primary Avalanche Problem – Wind Slab

Wind Slab

Aspect/Elevation

Likelihood

Size

Several inches of snow above 5500’ is likely available for transport by the increased wind today, and up to 3” of new snow will provide enough raw materials to build wind slabs. These new wind slabs forming today may be reactive, especially in locations that avoid the strongest wind.  Melt freeze crusts on the snow surface may exacerbate this problem by providing a icy bed surface. 

The existing snowpack structure leading into today remains a concern, though less so as more observations come in suggesting settlement and unreactivity. The possibility exists for an avalanche today to trigger deeper into the existing snowpack.

  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.

Forecast Discussion

Today’s avalanche problem is largely driven by the new snow expected today and any remaining snow above treeline available for transport into the ravines. Both factors include a level of uncertainty: new snow from snow showers can result in much less than predicted, and also significantly more than predicted. The OBS hints at the possibility of exceeding expected snow totals today, while the NWS is predicting less than 2” and much of that later this afternoon. Information from hikers, and relatively slow wind speeds recently leads us to believe that there may be several inches of snow available for transport, though ice crusts may or may not keep that snow locked to the ground.  

The existing snow structure keeping us at Moderate for several days is becoming less of a concern as great observations come in continuing to suggest stability.  

Additional Information

The Sherburne and Gulf of Slides ski trails are snow covered to Pinkham Notch with good skiing most of the way down. Beware of breakable crusts off trail.

Details on daily snowfall totals, precipitation type, total depth of snow and other information can be found on our page devoted to snow study plot data. Click here to check it out.

Recent snowpack and avalanche observations can be found here and on Instagram. Your observations help improve our forecast product. Please take a moment and submit a photo or two and a brief description of snow and avalanche information that you gather in the field.

Snow Plot Information

DateHN24HN24W
(SWE)
Density (%)HSTTotalAir TT MaxT MinSkyPrecipComments
02/28/20
05:05
24 CM 30.3 MM 17%28CM175 CM-15.0 C-2.5 C-15.0 COvercastNo precipitationView
02/27/20
05:12
2 CM 2.6 MM 16%NC146 CM-2.5 C-1.0 C-4.5 COvercastSnowView
02/26/20
05:48
1 CM 1.4 MM 10%NC145 CM-2.5 C6.5 C-4.0 COvercastSnow
02/25/20
05:20
0 CM 0 MM0CM145 CM-2.0 C6.0 C-2.5 COvercastNo precipitation
02/24/20
05:15
0 CM 0 MM0CM147 CM-2.0 C4.0 C-6.5 CFewNo 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
02/26/2025 F17 F .04 in .6 in15 MPH40 MPH

120 (ESE)

02/25/2026 F21 F .5 in 1.2 in16.7 MPH46 MPH

270 (W)

View
02/24/2027 F15 F 0.0 in 0.0 in40.9 MPH56 MPH

270 (W)

02/23/2024 F14 F 0.0 in 0.0 in31.5 MPH53 MPH

290 (WNW)

02/22/2014 F0 F 0.0 in 0.0 in58.9 MPH86 MPH

280 (W)

02/21/208 F-14 F 0.0 in 0.0 in44.6 MPH77 MPH

280 (W)

02/20/20-7 F-16 F 0 in 0 in59.5 MPH92 MPH

300 (WNW)

View
02/19/2020 F-11 F 0.15 in 1.3 in78.7 MPH112 MPH

270 (W)

View
View
View
02/18/2023 F5 F 0.35 in 3.9 in39.3 MPH93 MPH

200 (SSW)

02/17/2011 F-2 F .06 in .7 in50.1 MPH85 MPH

280 (W)

02/16/2013 F7 F .15 in 1.2 in56.3 MPH93 MPH

270 (W)

02/15/2014 F-4 F 0 in 0 in43.9 MPH77 MPH

250 (WSW)

View

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 02/03/2020 at 7:19 AM.

Jeff Fongemie
USDA Forest Service
White Mountain National Forest