General Bulletin for Friday, May 17, 2019

This forecast was published 05/17/2019 at 2:15 PM.
A new bulletin will be issued when conditions warrant.

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

Snow that fell on the Presidential Range earlier this week has now seen warmth and rain, bringing the return of an isothermal, springtime snowpack. Those looking to recreate on snow this weekend should review objective hazards that come with playing in big mountains. A thorough examination of these will help narrow down your focus and likely point your group toward a reasonably safe target. Open holes and undermined snow are widespread to various depths and will need to avoided on just about every slope. Icefall and rockfall are always possible and best dealt with by crossing quickly through the line of fire or avoiding slopes that have obvious chunks of ice that look like the leaning tower of Pisa. Any sort of fall in steep terrain can have consequences; bring the appropriate tools (ice axe, crampons, helmet) for your objective and don’t be afraid to use them even though others may not.

2019-05-17 General Bulletin

Danger Rating by Zone

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.

Mountain Weather

Continued rain and possibly a snowflake or two overnight Friday will give way to clearing skies on Saturday. Wind speeds will be elevated early Saturday morning, but should slow through the day while temperatures reach into the 40sF at mid-elevations. Unsettled weather returns Sunday, bringing rain showers through Tuesday with possible thunderstorms on Monday. Those who have the luxury of mid-week adventures should put Wednesday and Thursday on your calendar as the next likely spell of clear weather though forecast certainty 5 days out is tenuous.

Snowpack and Avalanche Discussion

Prolonged periods of melt have opened deep cracks and holes in the snowpack. Beware of these at the margins of the snowpack as well as places that have large cliff bands, like the Headwall in Tuckerman. Keep the following hazards in mind as you make terrain decisions in our dynamic spring backcountry conditions:

Steep snow and ice in gullies and trails can become very hard during any frozen periods in our spring melt/freeze cycles. Even in soft conditions, having crampons and an ice axe are well worth the weight in your pack.

Additional Concerns

As of this weekend, the Lion Head Winter Route is still the preferred hiking trail to access the summit from Pinkham Notch. The Sherburne Ski Trail is no longer recommended for use. The Sherburne, and all other ski trails or bushwhacks that access ski terrain this late in the season, have surfaces that are less durable than established hiking trails. In addition to getting your kit muddy and smelly, please be aware that slogging through mud accelerates erosion drastically and means a rockier start to next year’s skiing. This mantra also applies above treeline when accessing remote ski lines in Oakes Gulf or even the steep lines in Tuckerman like Dodges Drop, though for a slightly different reason. 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.

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.

The young man who was last seen heading up the Winter Lion Head Route on March 8 remains missing.  It is thought that he may have been intent on taking his own life. If that is the case, his remains may be somewhere with the Cutler River Drainage,  around the summit or within a few hours hike on the steep part of Lion Head Winter Route. Please report any potential clues to the NH Fish and Game officers at 603-271-3361 or to USFS Snow Rangers at mwactucks@gmail.com or via AMC Front Desk staff at Pinkham Notch Visitor Center. If it is clear that you have found him, please call 911.

Snow Plot Information

DateHN24HN24W
(SWE)
Density (%)HSTTotalAir TT MaxT MinSkyPrecipComments
05/31/19
05:20
0 CMTrace 0CM0 CM8.0 C11.0 C0.5 CBrokenNo precipitation
05/30/19
05:25
0 CM 0.0 MM0CM0 CM7.5 C7.5 C1.0 CScatteredNo precipitation
05/29/19
05:25
0 CM 22.3 MM0CM0 CM1.5 C4.0 C0.0 COvercastNo precipitation
05/28/19
05:25
0 CM 0.0 MM0CM0 CM0.5 C11.0 C0.5 CClearNo precipitation
05/27/19
05:15
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 05/17/2019 at 2:15 PM.

Helon Hoffer
USDA Forest Service
White Mountain National Forest