Snowpack and Avalanche Information for Saturday, May 30, 2020

This information was published 05/30/2020 at 7:40 AM.
A new bulletin will be issued when conditions warrant.


The Bottom Line

Unsettled weather will bring the potential for more thunderstorms, snow showers and an icy, snowpack over the weekend with clouds and fog shrouding the summit at times. If you venture to higher elevations, be prepared for a mixed bag of snow and weather conditions. The hot weather and melting this week has undermined snow and opened glide cracks and moats with some being quite deep. The snow showers in the forecast for Saturday night and Sunday may bring a couple of inches of snow that could obscure some of these hazards. While corn snow is the norm now at mid and upper elevations, timing may become more important as nighttime freezes return over the next several days. 

Keep the following hazards in mind as you venture into the backcountry:

Danger Rating

Above treeline, much of the snow is melted. Please limit walking to durable surfaces like rocks or snow and ice to preserve the delicate and slow growing plant communities in the alpine.

On Sunday May 17, 5 people were caught as they attempted to ski in Tuckerman Ravine and each were issued a Federal Citation and fined. Please remember that Tuckerman Ravine, Huntington Ravine, the Gulf of Slides and the East Snowfields remain closed until May 31 and possibly later. 

MWAC has moved to a Snowpack and Avalanche Information bulletin (known in prior years as a General Bulletin) until the end of the season. Snowpack and Avalanche Information is issued when unstable snow may exist within our forecast areas but after 5-scale avalanche forecasts have stopped. Please remember that avalanches can and do occur after 5-scale avalanche forecasts have ceased! 

Tuckerman Ravine, Huntington Ravine and the Gulf of Slides will remain closed to all use until May 31 and possibly later as winter conditions and deep snow remain. NH Governor Sununu has extended the Stay-at-home order until June 15.  

Please realize that volunteer rescue resources are currently limited due to concerns about community spread of the coronavirus. 

Mountain Weather

The hot weather comes to an end over the weekend with below freezing temperatures and snow arriving at higher elevations. But first, more thunderstorms on Saturday with cooler but still above-freezing temperatures through the day. Saturday night and Sunday will be in the 20’s with snow showers. Unsettled weather continues through the early part of the week with freezing temperatures at night at middle and upper elevations.  

Plan accordingly for quickly changing weather by reading the weather forecast before you head out (MWObs Higher Summits and NWS Hourly forecast). One tool to help reduce the chance for unwelcome surprises is the hourly weather information produced by MWObs summit staff. The NWS displays the hourly data going back 7 days here.

Forecast Discussion

One look at area streams and rivers serves as a reminder to the rapid melting that has occurred this past week. Dangerously undermined snow around streambeds, and rockfall were one outcome with thinning snowbridges over swollen streams another. Our snowpack is fully consolidated and settled at this point with generally firm corn snow in areas wind loaded over the winter. Around 20” of snow remains on the ground at 3800’ with lots of hikers last weekend returning to their cars with soaked feet after postholing on area trails. Don’t let the summer-like temps and green leaves at lower elevations trick you. 

As temperatures become cooler, be sure to check snow surfaces before committing to bigger lines. Subtle changes in aspect and temperature can turn smooth corn into an icy, slide-for-life surface. 

Additional Information

The alpine environment of the Presidential Range is home to plants that exist nowhere else in the world, in particular the area known as Monroe Flats. Bushwhacking from Lakes of the Clouds Hut to ski in Oakes Gulf takes you directly through the only non-transplanted home of Robbins Cinquefoil, a plant which only recently made it off the Endangered Species List. Stick to walking on durable surfaces like rocks, snow and ice to protect these plants and control erosion.

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 05/30/2020 at 7:40 AM.

Frank Carus
USDA Forest Service
White Mountain National Forest