THE EVOLUTION OF AVALANCHE FORECASTING ON MOUNT WASHINGTON

By Jake Risch and Frank Carus

Informing Safe Mountain Ventures

Intrepid backcountry skiers and snowboarders now regularly ski in avalanche terrain across the Presidential Range over the entirety of the winter season. Ice climbers, winter hikers, and mountaineers continue to climb and travel in avalanche paths outside of Huntington and Tuckerman ravines. To meet this increased use and support informed decision making, the U.S. Forest Service’s Mount Washington Avalanche Center (MWAC) is expanding avalanche forecasting to nearly the entire northern Presidential Range for the 2018-19 season.

Backcountry skiing is exploding in the Northeast. Ski companies are investing in research and development, delivering innovative, lightweight high-performance backcountry skiing and snowboarding equipment. Organizations
such as the Vermont Backcountry Alliance and the Granite Backcountry Alliance are organizing armies of volunteers to develop new gladed backcountry zones across VT, NH, and Western Maine. On Mount Washington,
skiers are increasingly expanding out from the typical Tuckerman Ravine ski routes and spring corn ski season. Intrepid backcountry skiers and snowboarders now regularly ski in avalanche terrain across the Presidential Range over the entirety of the winter season. Ice climbers, winter hikers, and mountaineers continue to climb and travel in avalanche paths outside of Huntington and Tuckerman ravines. To meet this increased use and support informed decision making, the U.S. Forest Service’s Mount Washington Avalanche Center (MWAC) is expanding avalanche forecasting to nearly the entire northern Presidential Range for the 2018-19 season.

Historically, the Mount Washington Avalanche Center provided a daily “microscale” avalanche forecast for each of the main ski routes in Tuckerman and climbing routes in Huntington. Starting at 6 a.m., snow rangers would analyze the latest weather observations, data from snow plots, and direct observations of each of the 18 forecasted routes to publish the daily avalanche forecast by 8 a.m. Each route was assigned a danger rating of low, moderate, considerable, high, or extreme. The rangers post these assessments using color-coded signs on “slat boards” at Hermit Lake, Harvard Cabin, and Pinkham Notch Visitor Center. The forecast provided further detailed information about the weather, expected avalanche problem, and other potential hazards for the day. This narrative forecast is posted online and provided in printed form adjacent to the avalanche information boards. The legacy rating system allowed people with little or no avalanche education to make quick route decisions based primarily on the danger ratings without a deeper understanding of the nuances of size, distribution, and the likelihood of triggering expected avalanche problems.

Mountain travelers in the rest of the Presidential Range relied on their own research of the weather and snow pack, trip reports from others, and extrapolations from the micro-scale forecast to make decisions about avalanche hazards. Human-triggered avalanches continue to occur outside of the two popular ravines. Skiers, riders, and climbers getting an early start were often on the trail before the avalanche bulletin was posted. Microscale forecasting was unique to Mount Washington. Other avalanche forecast centers across the Western U.S., Canada, and Europe provide mountain range scale forecasts that provide tools to understand the probability and size of potential avalanches across the elevation and cardinal aspects of the terrain.

This season, the MWAC provides an avalanche forecast that covers most of the northern Presidential Range, consistent with the use of the North American avalanche danger scale. The new forecast areal includes the Gulf of
the Slides, the ravines and alpine terrain accessible from the summit of Mount Washington, western flank and northern edge of the range, and the avalanche slide paths in Crawford Notch. Snow rangers make a detailed assessment for seven zones—replacing the 18 forecasted routes—in Huntington and Tuckerman ravines and provide an avalanche forecast for the new forecast area with information on the avalanche problem, size, probability, and the extent that it may be found in the terrain. Additionally, they provide a summary of the weather forecast with implications for changes in avalanche conditions throughout the day. The avalanche center is moving the target for publishing the forecast to 7 a.m. The new forecast also includes graphical tools to understand the avalanche problem, probability, and likely size to complement the written narrative.

The new system does not provide a danger rating for each gully or route; instead, it provides information to help people identify the avalanche problem type wherever it is found in the terrain. Publishing the bulletin at 7 a.m. requires forecasters to rely more on the prior 24-hour weather and previous day’s field observations, rather than a morning field observation. The goal is to provide information that empowers climbers, skiers, and riders to make informed decisions, manage their own risk, and choose appropriate terrain for the day. Mountain travelers, now more than ever, need to perform their own assessments in the field to confirm the avalanche problem and select a route. The avalanche forecast should be a starting point for individual field observations and decision making as people head into avalanche terrain.

Forecasting for the entire range requires that the snow rangers travel and observe the snow pack around the range. One trade-off for this is search-and-rescue response times for accidents and incidents in Tuckerman and Huntington ravines. Over the winter season, the rangers may not be in the Cutler River Drainage to respond immediately to an accident on weekdays. They do plan on anticipating busy times in the Cutler River Drainage and being close-by when possible. Additionally, there are full-time caretakers at Hermit Lake and Harvard Cabin that can initiate a search-and-rescue response. The snow rangers will still be in charge of coordinating the response and activating other search-and-rescue teams as the situation dictates. Winter travelers should be prepared to provide immediate first aid and transport for their own party and carry enough warm gear to wait hours for a rescue party to respond. The best tool to help people survive and thrive in avalanche terrain is to provide information and encourage safe travel. An earlier advisory, covering more areas that are seeing more use and more incidents will assist in better decision making.

During the annual spring pilgrimage to Tuckerman Ravine, the MWAC will shift focus back to the Cutler River Drainage. Starting at the end of March or beginning of April, the snow rangers will circle the wagons at Hermit Lake and do what it takes to provide for a safe experience for that crowd. This will likely mean using the slat boards to communicate the simplest message to largest number of people in the form of gully-by-gully ratings.

Expanding the scope and scale of the avalanche center’s responsibility will put a strain on already tight resources. The Friends of Tuckerman Ravine (FOTR) is stepping up to expand their support for MWAC and will be reaching out to the backcountry ski community for help. To make the full vision a reality requires additional resources and infrastructure. Every dollar that FOTR contributes towards infrastructure and operational costs frees up federal government dollars to pay for snow ranger salaries. Some of the short-term goals of FOTR include purchasing and installing snow telemetry (SNOTEL) infrastructure around the range. These sites will provide real-time snowpack data for forecasters, mountain guides, skiers, riders, and climbers to asses conditions and inform travel choices. Another goal is to expand operational funding of the MWAC to enable hiring an additional seasonal snow ranger.

Over the next year, FOTR will be hosting outreach events and ramping up fundraising campaigns to support the expansion to range-wide forecasting. The 19th annual Tuckerman Inferno pentathlon, the organization’s largest fundraiser, will be held April 13, 2019. Plans are in the works for a summer trail-running event on Mount Washington, and crowdfunding campaigns to fund additional SNOTEL sites around the range. For more information and to donate to support expanded forecasting in the presidential range, visit www.friendsoftuckermanravine.org.

Avalanche forecasters don’t visit every area they forecast! It just isn’t practical to visit every location in any range in the country that has avalanche forecasts. Workloads and daylight won’t allow it, and low-use areas are probably that way for good reasons. The MWAC field days will likely follow hot spots of use. Though some places will rarely be visited by a forecaster, the forecast will be helpful to identify and avoid avalanche problems. Identifying patterns is part of process and keeping up with snow and weather history and the day’s forecast helps folks stay out of trouble, and hopefully, find the goods.