General Bulletin issued on Friday, May 10, 2019

This forecast was published 05/10/2019 at 4:22 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. 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

Do you ski? If so, I know what you are thinking: there can’t be many weekends left with good skiing in the ravines, and you’d be correct. As our snowpack level decreases, spring hazards increase. Warm rain today (Friday) will further undermine snow and increase the size and depth of waterfall holes. Warm weather over the last week has increased the size of moats near rock faces and deepened melt holes. Large rocks at the bottom of some ski runs have emerged and pose an additional threat to sliding falls.

The good news is that spring hazards can be managed and there’s still plenty of snow in the ravines. For example, limit your exposure to dangerous waterfall holes by avoiding travel near the obvious waterfalls. Friday’s rain will increase the water flowing over the Lip area, and the stream flowing through the Little Headwall. You can avoid your exposure to huge chunks of ice that can fall from above areas like Lunch Rocks by…avoiding Lunch Rocks and areas in the fall line of ice chunks remaining in the Headwall.

 

Danger Rating by Zone

This weekend in Tuckerman Ravine, Hillman’s Highway, Left Gully and Lobster Claw may offer ski runs with reduced hazards from icefall and waterfall holes if the surface snow warms and softens. Many other backcountry zones also have fewer of the potentially deadliest spring hazards. Crampons and ice axe will be necessary tools to travel on steep slopes on Saturday, including the Lion Head Winter Route as cooler temperatures limit snow softening to the slopes getting the most direct sun. The tops of gullies may not soften at all on Saturday though this depends on subtle factors such as cloud cover and wind speeds. Sunday is forecast to be much warmer, with a mix of clouds and sun.

2019-5-10 General Bulletin

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

After a rainy day on Friday, the summit temperature is expected to drop, leading to a chance of mixed precipitation late, possibly continuing into Saturday morning. Summit temperatures will remain in the 20sF during the day Saturday as the skies gradually clear. After a refreeze Saturday night, Sunday is forecast to be mostly sunny and warmer with a summit high temperature in the upper 30sF.  Wind should remain consistent at 45-55 mph from the NW through the weekend. Looking ahead, Monday and Tuesday bring the chance of mixed precipitation and possibly snow.

Snowpack and Avalanche Discussion

Prolonged periods of melt have opened deep cracks and holes in our snowpack, as flowing water exacerbated by rain Friday further undermined snow and opened stream channels. Areas of very icy snow will keep skiers on their toes Saturday, though the return of warming conditions on Sunday should restore some degree of edgeability to the surface snow. Minor sluffing becomes likely during warm conditions and the resulting sluff channels may complicate descents. 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, such as the Lion Head Winter Route, become very hard during any frozen periods in our spring melt/freeze cycles requiring crampons and an ice axe to climb with security. The tops of many ski descents also fit this description.

Additional Concerns

Due to heavy snow and wind loading this winter, the  Lion Head Winter Route remains the preferred, easier route to the summit from the east side. The Sherburne and Gulf of Slides ski trails are no longer completely snow covered to Pinkham Notch. Expect ice, open stream crossings, rocks, bare patches and plenty of mud.

The Sherburne is currently closed at the #7 crossover, 0.7 miles downhill of Hermit Lake (see red path in image below) though this section may not survive Friday’s rain. A rope will direct skiers to the Tuckerman Ravine Trail to to prevent damage that results from walking on the muddy Sherburne trail. Please remove your skis and walk down the Tuckerman Ravine Trail to avoid collision with the many hikers on the 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.

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 05/10/2019 at 4:22 PM.

Jeff Fongemie, Snow Ranger
USDA Forest Service
White Mountain National Forest