By Brian Fitzgerald, Director of Science & Education | November 15, 2021

Chances are, you’ve heard a meteorologist refer to weather conditions as near, above, or below “normal.”

But just what is normal for where you live? Who gets to say? How is it even determined?

Every 10 years, the National Centers for Environmental Information [(NCEI) formerly known as the National Climatic Data Center] are charged with generating climate statistics known as U.S. Climate Normals, based on requirements from the World Meteorological Organization (WMO) and National Weather Service (NWS).

These statistics are calculated for thousands of locations throughout the country, across a uniform 30-year period, and serve as a baseline to compare against weather forecasts just like the one you might have seen today. Statistics such as daily, monthly, seasonal, and annual averages of temperature, precipitation and other climate variables are computed for roughly 15,000 stations nationwide, including the summit of Mount Washington based on weather data transmitted from Mount Washington Observatory (MWO) staff. With the anticipated release of the new normals in late spring 2021, MWO staff naturally wondered: what has changed?

As countless investigations such as the US National Climate and IPCC assessment reports have shown, a warming planet has led to climate changes throughout the entire globe, with regionally specific trends. Changes unique to Mount Washington, as shown by Murray et al. (2021, “Climate Trends on the Highest Peak of the Northeast: Mount Washington, NH”) include elevation-dependent warming rates over many decades. With this in mind, many were curious: What if any evidence of climate change could be seen by comparing the 1981-2010 and 1991-2020 climate normals, even though these two datasets have 20 over-lapping years between them.

To help us answer some of these questions, our summit interns, with guidance from NH State Climatologist Mary Stampone (a MWO trustee) and myself, took on the investigation this past summer to help us understand not only what may have changed on the summit (KMWN, 6,288 ft.), but also up and down the Mount Washington Valley at sites including Pinkham Notch Visitor Center (GHMN3, 2,025 ft.) and North Conway Village (NCON3, 522 ft.). As the interns began to compare each station’s 1991-2020 climate normals set versus the older 1981-2010 set, three broader stories began to appear:

An increase in annual average temperature, with variation among the three sites.

As shown in the data table below, all three sites saw annual average temperatures increase in the new normals, with North Conway showing evidence of warming every single month of the year. All told, the annual average temperature at North Conway is +1.6F degrees warmer than the previous set of normals. Mount Washington’s annual average temperature warmed +0.7F degrees, while Pinkham Notch saw a nearly even split between months that warmed or cooled in comparison, making an annual average temperature that warmed just +0.2F degrees.

Table 1. Mean average monthly and annual temperatures for KMWN, GHMN3, and NCON3, New Hampshire, for 1991-2020 (with comparison to the prior 1981-2010 normals).

An increase in annual average snowfall, particularly later in the season.

When comparing the three sites and their relative changes in annual snowfall, Pinkham Notch surprisingly saw the largest increase for total snowfall. Among the sites, Mount Washington now averages 281.8 inches annually, with Pinkham averaging 135.8 inches, and North Conway 84.0 inches. Pinkham’s increase to 135.8 inches annually is now 9.7 inches higher than in the previous normals, versus 4.0 inches more in North Conway and just 0.6 inches more on the summit of Mount Washington.

In addition to the variations among the three sites, it was notable that within the snow season, all three stations saw an overall increase in snowfall in February (see Figure 1.). This increase across the board slightly later in the snow season is worthy of a closer look to understand how the nature of our winters are changing, and what the impacts may be to the region’s snow packs.

Figure 1. Change in liquid equivalent snowfall at KMWN, GHMN3, and NCON3 between the 1981-2010 and 1991-2020 climate normals.

Changes in precipitation varied drastically among the three stations.

Finally, when comparing the three stations’ new precipitation normals versus the prior set, fairly noticeable variation throughout the year, and from station to station, seems to appear. Overall, precipitation dipped more than five inches annually on average at Mount Washington, while Pinkham Notch gained almost five inches, and North Conway saw a marginal annual increase of 0.5 inches (see Figure 2.).

Figure 2. Change in precipitation at KMWN, GHMN3, and NCON3 between the 1981-2010 and 1991-2020 climate normals.

One area of consistency among the three stations appeared in October, where a general increase in average precipitation totals was observed. From a meteorological perspective, the team was unable to complete a forensic investigation of particular storms or weather patterns in the 2011-2020 timespan that may have accounted for this increase; however, best guesses at this stage may point to an increase in the intensity or perhaps even frequency of extreme precipitation events from coastal, bomb-cyclone type nor’easters.

All together, the investigation comparing the new climate normals versus the prior set across the Mount Washington Valley has uncovered some broad-based differences and a number of lingering questions. Future investigations into these datasets could shed light on precisely what, if any, shifts in the snow season may be occurring, and how such changes may differ across a variety of mountainous terrain and elevation.

Although this investigation was a comparison of two largely overlapping datasets, versus an analysis of longer-term climatological data, the research conducted by our summit interns has given MWO a clearer understanding of what our “new normal” on the summit of Mount Washington is. If you’re curious to learn what your “normal” weather is in your backyard, we encourage you to visit ncei.noaa.gov to search for climate normals near your town. Additionally, to learn more about MWO’s recent climate normals project and read the summary report, visit mountwashington.org/research.

MWO Observers Jay Broccolo and Sam Robinson, and MWO summer interns Alexandra Branton, Michael Brown, Madeline DeGroot, and AJ Mastrangelo contributed to this story.

By Nicole Tallman, Past Weather Observer & Education Specialist | November 15, 2021

An example of a hurricane’s eye and surrounding eye wall, where the most ferocious winds of the storm occur. NOAA photo. 

Come late summer and early fall, we begin to hear more about activity in the tropics. The threat of hurricanes becomes more prominent and you may find yourself thinking about how and why these storms are forming.

One of the strongest storms known to people, a hurricane begins its life cycle as a cluster of thunderstorms in the tropical or sub-tropical waters. These waters tend to be their warmest in the late summer after intense summer sunlight has been beating down for several months. The air surrounding the surface of the water begins to heat up, evaporating some of the moisture from the ocean. This is the initial ingredient needed to begin building a thunderstorm.

Once the air is warm and moist, it begins to rise through the cooler atmosphere. The ideal set up for developing strong storms is when the atmosphere is cool, yet the ocean waters are still warm. Moving into early fall, the oceans hold on to their warmth and the air begins to cool, creating “instability” for the warm moist air at the surface of the ocean. The air continues to rise in the atmosphere, creating a thunderstorm.

The ocean continues to warm the air closest to the water’s surface and in turn, feeds the rising pocket of air. This allows for low-pressure to form because the air is rising up higher into the atmosphere. Low-pressure centers in the Northern Hemisphere rotate counterclockwise, and in the development of a hurricane, you will start to see the cluster of thunderstorms become more organized and even begin to rotate.

Once the system has its own cut-off low-pressure system, winds will begin to increase, creating a stronger storm. Once winds reach 39 mph the storm gets the label of a tropical storm, and they become a hurricane at 74 mph.

The categories of a hurricane on the Saffir Simpson scale are wind-dependent, and as the storm produces higher and higher winds, it can increase itself to a category 5 hurricane, the strongest storm known. A very indicative physical feature of a strong hurricane is its eye. This is the calm center of the low-pressure system where winds die down and rain ceases. However, surrounding the eye is the eye wall, which has the most ferocious winds of the storm. Very strong hurricanes will develop this eye, which can clearly be visible from satellite, like in the example below.

A few hazards of hurricanes include the devastating wind speeds, storms surge, very strong thunderstorms and even tornadoes imbedded in the rain bands of the hurricane.

Most of these hazards dwindle once a hurricane makes landfall and is no longer over its main energy source, the warm ocean waters. However, hurricanes that have weakened or died out can continue to impact the weather of surrounding areas and areas “downstream” from the storm.

The immense amount of moisture and energy from hurricanes have been known to make their way from areas such as the gulf or southern east coast of the U.S. all the way to the Northeast. While it is less common for areas in New England to receive a direct impact of a hurricane, we quite frequently will get saturating rains, elevated winds, or a round of very inclement weather due to the remnants of tropical storms and hurricanes.

One recent example is Hurricane Isaias, which occurred in August 2020. Isaias made landfall on the coast of North Carolina with wind speeds sustained near 85 mph. It caused significant storm surge, and multiple tornadoes at landfall. Once on land, the storm weakened to a tropical storm and continued to impact cities such as New York and Philadelphia.

Remnants eventually made their way all the way north to the summit of Mount Washington, where the crew experienced heavy downpours and a max gust wind speed of 147 mph, a new record wind speed for the month of August.

In his blog dated August 5, 2020, Weather Observer Sam Robinson wrote, “Suddenly at 8PM sharp, the chart spiked showing a gust of 147 mph! The wind database was cross referenced and sure enough, it showed a peak gust of 146.7 mph from the southeast! Our crew celebrated the feat as it set all of our personal records and we then shared the news with the state park crew who also had a few new personal records set. We soon discovered that besides personal records, it also set a new all-time wind record for the month of August! The previous record was 142 mph set back in August of 1954.”

Massive and intense, tropical storms can impact areas all the way from their development to far past their site of landfall.

By Peter Crane, Curator, Gladys Brooks Memorial Library | June 15, 2021

Mount Washington and Ammonoosuc Ravine (looking from the west). The large dot marks the approximate site of the Forgays tragedy. Bradford Washburn photo.

On Monday February 1, 2021, an avalanche in Ammonoosuc Ravine took the life of Ian Forgays, 54, of Lincoln, Vermont.

Forgays, a very experienced backcountry skier, was skiing alone in this ravine on the western side of Mount Washington. Weather conditions were favorable with the temperature in the single numbers and teens and winds averaging 33 miles per hour that day. The Mount Washington Avalanche Center had issued a “low” rating for avalanche danger, but it is important to under-stand that low hazard does not mean no hazard, and even when such hazard is minimal, it is not unusual for areas of unstable snow to exist in some locations. As the Center’s forecast for the day stated, “the potential for small avalanches of wind drifted snow remains in isolated areas at mid and upper elevations.”

Presumably Forgays skied onto such an unstable pocket, which released and carried him downward. To compound his predicament, the spot lay in a “terrain trap” — an area where a broader slope of snow could slide downward into a tighter, funnel-like constriction, resulting in relatively shallow snow piling up into a deep mass over the skier. This was a mass from which he could not escape; new snowfall the next day, with a subsequent avalanche, buried him only deeper.

Friends of Forgays alerted authorities to his absence late Tuesday. On Wednesday, a full field search commenced, focused on Ammonoosuc Ravine. Forgays had been using an avalanche transceiver, or beacon—a small device that sends out an electronic homing signal which can be received by another such device—which was essential in locating him. His signal was acquired at about 4:30 p.m.; it would take more than an hour and a half to dig through almost 13 feet of avalanche debris to reach him. By then Ian Forgays had succumbed to asphyxiation.

The search and recovery effort included personnel from the New Hampshire Fish and Game Department, the White Mountain National Forest/Mount Washington Avalanche Center, and the all-volunteer Mountain Rescue Service.

The Mount Washington Avalanche Center issued a detailed incident report, assessing the snow conditions and considering the decisions made by Forgays. The Center noted that Forgays was a very capable and accomplished skier, and such skiers, honed by experience, sometimes accept calculated risks. Unusual circumstances can cause those calculations to go awry, to the adventurer’s peril. In this case, the Center stated, “skiing technical lines, in a thin snowpack above a notorious terrain trap, with no partners, even on a Low danger day, raises the stakes tremendously.” We send our condolences to Forgays’ family and friends.

According to available records, 17 people have died in avalanche incidents on Mount Washington; this number does not include others who have been caught, buried, or injured by such snow slides on the mountain and who have lived to tell the tale.

The first two people who died in an avalanche-related incident on Mount Washington were Philip Longnecker, 25, and Jacques Parysko, 23, who died in January of 1954 while camping in an igloo-like snow shelter built imprudently just beneath the Tuckerman headwall. Their shelter was hit by a small snow slide, burying Longnecker and leading Parysko to attempt an escape by hiking ill-prepared down the Sherburne Ski Trail, where he succumbed to hypothermia.

Another early avalanche victim was Aaron Leve, 28, who was hiking in Tuckerman Ravine in February of 1956. He was with four others who were struck by the snow slide—indeed one probably triggered it—but he alone was fully buried, and it took an extensive effort to locate his by-then-lifeless body.

Following those incidents, it seems that all such tragedies involved either skiers or climbers—the latter including technical ice climbers as well as non-technical winter climbers on Lion Head.

As noted earlier, Ian Forgays, 54, died in an avalanche in Ammonoosuc Ravine in February of this year. His was the first such incident on that side of the mountain. Perhaps surprisingly, no skier has yet died in an avalanche in Tuckerman Ravine. Three skiers have died in such incidents in the aptly-named Gulf of Slides— John Wald, 35, and his companion Todd Crumbaker, 29, in one avalanche in March of 1996, and David McPhedran, 42, in January 2000. More recently, Nicholas Benedix, 32, died in an avalanche in April 2019 while skiing down the Ravine of Raymond Cataract, a not-so-often skied route lying on the east side of the mountain, between Tuckerman Ravine and Huntington Ravine.

Mount Washington from the east (from atop Wildcat “D” peak). The summit of Mount Washington is in the clouds, as is so often the case. From left to right can be seen the Gulf of Slides, Tuckerman Ravine, the Ravine of Raymond Cataract, and Huntington Ravine, each of which has been the scene of one or more avalanche fatalities.

Mountaineers venturing onto the steep slopes of Huntington Ravine, favored by technical ice climbers, have come to grief when unstable snow perched precariously in that precipitous terrain has overcome them. In February 1964, Hugo Stadtmüeller, 28, and John Griffin, 39, lost their lives as a result of such a snow slide. Thomas Smith, 41, succumbed to an avalanche in Huntington in February 1991; his climbing companion was injured but survived. Peter Roux in January 2018, and Jimmy Watts, 24, in March 2013, were solo climbers who died as a result of avalanches in this ravine.

In early winter it is not unusual for ice climbers to ply their craft on the headwall of Tuckerman Ravine, and two such climbers, Scott Sandberg, 32, and Thomas Burke, 46, in separate parties, were lost to an avalanche in November of 2002, in an incident that involved seven individuals.

The slopes of Lion Head, one of the standard not-so-technical routes for winter ascent of Mount Washington, have been the scene of avalanche tragedies as well. In January 1982, Albert Dow, 28, a volunteer from the Mountain Rescue Service, lost his life while serving in the search for two missing climbers. In January 1996, Alexandre Cassan, 19, died while attempting an ascent of the mountain via Lion Head.

Of Mount Washington’s avalanche toll, five were skiers, seven were technical climbers, and five were non-technical climbers or hikers. All were male. The average age of the victims was 33, with a range from 19 to 54. Two deaths occurred in November, none in December, six in January, three in February, three in March and three in April. All of these people were on the mountain for a day of enjoyment, to indulge their passion for recreating in the outdoors and rising to mountain challenges, but it was a day from which they never returned.

For those with an interest in exploring Mount Washington, or other such mountains, in winter and spring, avalanche knowledge can be a prerequisite for safe adventures. Especially if you have an enthusiasm for skiing the steeps, or climbing challenging slopes, taking an avalanche safety course should be on your to-do list. Many climbing schools or guide services offer such instruction, from basic awareness sessions to detailed technical courses in snow science and rescue coordination. Even with such training under your belt, sometimes “a little knowledge can be a dangerous thing,” and humility and acknowledgement of what you don’t know about the complicated subject of avalanches should remain a guiding principle. (Renowned Swiss guide André Roch once reminded a group of his colleagues, “It is good you are all experts. But the avalanche, it does not know that you are experts!”) Check, and strive to understand and abide by, the avalanche forecasts issued by the Mount Washington Avalanche Center. Don’t just take a look at those forecasts once in a while—read them daily through the winter, to further enhance your understanding of the evolution of the snowpack and its potential hazards throughout the snow season. Pack along “the holy trinity” of avalanche safety tools —beacon, probe, and shovel —and practice their use, realizing that speed in use of a beacon can literally mean the difference between life and death. And always remember that alluring as the powder or ice or summit may be, the mountain will be there for another day.

The waves of avalanche snow have been compared to ocean waves, in their power, but also in their tragic impact. Indeed, it should never be forgotten that, “The snowy torrents are like the deep sea: they seldom return their victims alive.”