General Bulletin issued on Tuesday, April 30, 2019

This forecast was published 04/30/2019 at 7:29 AM.
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

Below freezing temperatures this week are resulting in hard, refrozen snow in much of our terrain. Continued wintry weather, with only limited warming, means that while we may see a few periods of softening corn snow it should be the exception rather than the norm. Long sliding falls on this hard, refrozen snow could be complicated by the number of spring hazards now exposed. Bring crampons and ice axe, using them to prevent a fall, and consider the consequences of a fall in any terrain you choose. Our generally refrozen snowpack presents minimal avalanche concerns with small wind slabs formed over the weekend seeming generally stable. At least some snow is in the forecast and could easily result in elevated avalanche danger. Continue to watch for quickly changing conditions as you play in the mountains this week.

2019-04-30-general_bulletin-printable

Danger Rating by Zone

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.

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

A trace of new snow last night is the only new snow since the approximately 4” of new snow that fell over the weekend. Our middle and upper elevation terrain has generally remained below freezing, a trend which continues today. Snow showers today should produce minimal accumulation. Slightly warmer temperatures are forecast for the rest of the week, with periods of mixed rain, snow, and other wintry precipitation forecast late Wednesday through Friday. Windows of sun may combine with above freezing temperatures to, at times, allow some snow in the Ravines to soften, but expect quickly changing conditions to be the norm all week.

Snowpack and Avalanche Discussion

The prolonged period of melt last week opened deep cracks and holes in our snowpack, as flowing water undermined snow and opened some stream channels. The subsequent freeze with minimal melting this week is now making long sliding falls on hard, icy snow a prominent concern. With snow in the long range forecast, remember that new snow and wind can rapidly build wind slabs and elevate avalanche danger. 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, becomes very hard during any frozen periods in our spring melt/freeze cycles. This week seems to be presenting more freezing than melting. Currently, the Winter Lion Head route as well as areas of the snowpack that were scoured by the wind are icy and require crampons and an ice axe to climb with security.

Additional Concerns

The Sherburne and Gulf of Slides ski trails are no longer completely snow covered to Pinkham Notch. Expect ice, open stream crossings, rocks and bare patches. The lower ⅓ of the Sherburne is closed, with a rope directing skiers to the Tuckerman Ravine Trail. Cross over to the Tuckerman Ravine Trail at this point of your descent 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 04/30/2019 at 7:29 AM.

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