Historical Posts Archives - Page 2 of 378 - Mount Washington Observatory

May 2022

Mt Washington Summer Season 2022 Information

2022-05-23 19:25:29.000 – Ryan Knapp, Weather Observer/Staff Meteorologist

With summer quickly approaching, you might be looking for information to plan a visit to the summit of Mount Washington. There are various entities that make up a visitor’s experience in the summer. It’s important to plan according to the different schedules of these organizations. So, below are some references you can utilize to help your visit go smoothly.

Mount Washington Observatory:

Weather Station Tours – Our tours return this summer and will be available to Observatory members when the Mt. Washington State Park Sherman Adams Visitor Center is open to the public (see below). These tours now require a reservation prior to your visit. For information about how to reserve a spot and other policies, please click HERE.

Observatory Tours are a member benefit offered to Mount Washington Observatory members who make a donation of at least $60 a year or $5 a month per household. If you are not a member and would like to join our unique community of donors, you can make a donation online HERE and enter your Transaction ID number when you register.

Our Extreme Mount Washington museum is located inside the Mt. Washington State Park Sherman Adams Visitor Center; it is open whenever the NH State Park Visitor Center is open to the public (see below). Additional information is available HERE.

If you are planning a hike, you should always check out a forecast in order to dress and pack accordingly. Mount Washington Observatory produces a 48-hour Higher Summits Forecast twice a day and post it by 5 am and 5pm available HERE.

Mount Washington State Park:

Mt. Washington State Park, Sherman Adams Summit Building, Concession, Tip Top Historic Site operating hours are available halfway down their website HERE. Note that the Historic Tip Top House is closed for the start of the season as interior renovations are finished. Hours are subject to change, so please check their webpage and/or contact them directly (information at the top of their page) for the most current information.

Mt Washington Auto Road:

Information for the Mt Washington Auto Road can be found on their website HERE and their schedule of operation is available HERE and their various rates are available HERE. Hours of operation are subject to change, so please check their page, their social media pages, and/or contact them directly for the most current information.

The Mount Washington Cog Railway:

Information for the Mount Washington Cog Railway can be found on their website HERE and their schedule and ticket information is available HERE. Hours of operation are subject to change, so please check their page, their social media pages, and/or contact them directly for the most current information.

White Mountain Huts of New Hampshire:

Information about the AMC network of lodges, cabins, bunkhouses, campsites, and high mountain huts is available HERE. Information about the RMC high mountain huts is available HERE. Information about the HMC cabin and tent sites is available HERE. Information about the USFS White Mountains camping and cabins is available HERE. Camping is forbidden within NH State Park property as well as above treeline (except on 2+ feet of snow) within the White Mountain National Forest and there are other various rules and restrictions to be aware, all of which are available HERE.

Trail and Tuckerman Ravine conditions:

Trail conditions can be found HERE or by reading from various forums or Facebook Groups available. Tuckerman Ravine conditions, when available, can be found on the Mount Washington Avalanche Center page HERE.

Sunrise from the summit of Mt Washington, NH at Mount Washington Observatory on 19 May 2022

Sunrise from the summit on 19 May 2022

Ryan Knapp, Weather Observer/Staff Meteorologist

Research to Look at Near-Surface Lapse Rates: the Amount of Temperature Change with Elevation

2022-05-17 18:55:34.000 – Jay Broccolo, Weather Observer & Meteorologist

The MWOBS automated weather station at elevation 4,300 feet, part of the Mount Washington Regional Mesonet.

We recently completed a technical overview of the Mount Washington Regional Mesonet (MWRM) for submission to a scientific journal. The paper coalesces the history, metadata, instrumentation, functions, and uses of the MRWM, our network of remote weather stations at varying elevations. The overview also explains the value of a mesonet in the White Mountains along with the unique challenges presented by the terrain and harsh weather.

The overview is beneficial not only for our work but also other organizations that operate a series of automated weather stations in close enough proximity to measure, record, track, and communicate mesoscale meteorological phenomena. By mesoscale, I am referring to an area larger than microscale, like a town or city’s environment, but smaller than synoptic scale, a large country or continent. Mesoscale, typically between tens of kilometers to several hundreds of kilometers, essentially refers to an area large enough to encapsulate storm-scale systems, like cyclones, extra-tropical cyclones, frontal systems, and squall lines.

Organizing all of this information will make it much easier for MWOBS observers and the scientific community to access this information as well as assist other mesonet system administrators to overcome some of their own unique challenges, establish a new mesonet, add further stations to one in existence, or maybe spark some new ideas and technology solutions.

We look forward to making our overview available to the public in the near future.

As we move into the summer, our intern program is back in full force and focused on research and weather operations. One of the research projects that will occur throughout 2022 and bring us into 2023 is the establishment of near-surface lapse rates on the windward and leeward flanks of Mount Washington.

One of our new summer interns, Henry Moskovitz, will be starting this project with a literature review, initial collection of data, and establishment of methods of analysis. Henry will be fortunate to get a first look at the summer seasonal lapse rates and see how they compare to what is generally known.

The project will make use of our MWRM, provide undergraduate research experience, and produce research that will add to the scientific community, improve our forecasting toolkit to better prepare the recreational and business community, and improve our understanding of climate change and its effects on the alpine zone.

As we dive into the research project this summer, let’s welcome Henry and get to know him a little bit better…

————————————————————————-

Hi Everyone,

Wednesday, May 11 was my first day as the new intern on the summit of Mount Washington, and only a week prior I was finishing my last final exam at school all the way down in Daytona Beach, Florida.

After exams, I drove back to my home in Massachusetts, where I relaxed for a few days before heading up here. Apparently, I must have packed the warm weather with me before departing Florida because the ridge, currently sitting over us and producing record-high temperatures, looks like it was dragged up Interstate 95.

While on the subject, temperatures will comprise much of my work here this summer. My mentor, Weather Observer and Meteorologist Jay Broccolo, has begun providing me with a rough overview of the research that I’ll be helping him complete.

Jay has been developing a study to establish near-surface lapse rates on Mount Washington. In more simple terms, this means we are looking to determine how the air temperature changes up and down the mountain under different conditions. Establishing more accurate baselines for these lapse rates will help with forecasting precipitation and predicting the effect(s) that changing temperatures will have on the local alpine climate and the surrounding environment.

I am very excited to participate in this important work and I am already finding the observatory to be a dynamic, engaging workplace. I look forward to all I will get to learn this summer!

–Henry

Henry Moskovitz

Jay Broccolo, Weather Observer & Meteorologist

Spring Weather Means it’s Time to Fly (or Hike)!

2022-05-10 08:24:31.000 – Sam Robinson, Weather Observer/Engineer

As winter starts to lose its tight grip on the higher summits this spring, the Home of the World’s Worst Weather has begun to show a bit of forgiveness. Overall, winds have relaxed a bit, temperatures have become less bone-chilling, and the snow and ice is beginning to disappear.

This seasonal improvement in weather tends to lead to increased recreational activity around the mountains but also more favorable conditions for aviation activities. Over the past few weeks, we have witnessed multiple training exercises from both American and Canadian search and rescue helicopters due to the unique terrain of the White Mountains, and the availability of the helicopter landing pad located just off the summit cone.

Our summit weather observing station submits hourly weather observations or METAR’s (METeorological Aerodrome Reports) to the National Weather Service as part of a network of nationwide stations to help keep the aviation community safe. However, we are unique and differ from most METAR weather observing stations since most stations are located at airports. While we are not an airport and we are not helping planes land, nor do we have any runways, we do have the heli pad!

Royal Canadian Airforce 413th Transport and Rescue Squadron coming in for a landing.

One of the more notable helicopter landings I’ve experienced so far this year has been the Royal Canadian Airforce, specifically the 413 Transport and Rescue Squadron from Nova Scotia. This is the first time I have seen them in our area, as they normally stay in…well, Canada! The unique mountainous terrain of the White Mountains is a great place for the squadron to train because it is similar to the terrain that they service in Canada but is also relatively close to airports (and heli-pads). This helps make the training exercises easier to coordinate, easier for the helicopter to stay fueled up, and also provides rest time for the crew when needed.

Speaking of the helicopter itself (as I am a gearhead), it is an AgustaWestland Cormorant CH-149. I believe it is the largest helicopter to routinely land up here on the summit, and appears to be one of the largest single rotor choppers I have seen and photographed here.

Crew members of the RCAF 413th Transport and Rescue Squadron taking some pictures of their own.

The large, bright yellow “Cormorant” was down in our region this past week for training, and according to an article in the Conway Daily Sun, it was the first time down here since 2019 due to the pandemic. The crew based themselves out of the Eastern Slopes Airport in nearby Fryeburg Maine.

Along with our Canadian friends from the R.C.A.F., the United States Coast Guard and Air National Guard have been doing some flights around our area this spring as well. The U.S.C.G. based out of Cape Cod, MA operates a Sikorsky MH-60T Jayhawk dressed in the very distinguishable orange and white paint scheme while the U.S.A.N.G. out of Vermont operates a Sikorsky HH-60 Blackhawk, which is used for search and rescue in our region, dressed in standard army green with a white and red cross on the side.

United States Coast Guard Sikorsky MH-60T Jayhawk on the helicopter landing pad.

United States Air National Guard Sikorsky HH-60 Blackhawk flying over the Great Gulf.

Another notable landing earlier this year included the US Army Chinook CH-47 twin rotor transport helicopters. These may actually take the cake for the largest helicopters to land here, they are pretty massive! It was the first time I had ever seen them fly and land up here and also the first time I had ever seen them in person. They flew in after a recent fresh snowfall, and the landing definitely kicked up an impressive snow dust cloud. Definitely was a sight and sound that I will never forget!

United States Army Chinook twin-rotor transport helicopter landing with its twin flying in the background.

Although most of you probably are not trying to fly and land helicopters up here on the higher summits, you may be looking to recreate in the mountains this spring. Before heading out on your next adventure, be sure to check out our 48-hour Higher Summits Forecast in order to know what to expect up in the alpine zone. It is important to remember that while conditions in the valley and at trailheads may feel almost summer like at times, winter weather is still very possible above treeline.

If you are not looking to hike but still looking to visit the summit, be sure to check out the websites of our partners on the mountain for updated opening dates and other information, like Mount Washington State Park, the Mount Washington Auto Road, and the Cog Railway.

USANG Blackhawk heading back towards Vermont.

Enjoy the spring weather because summer will be here before we know it! Happy trails (or road / rails )!

Sam Robinson, Weather Observer/Engineer

A Look Back at Measuring the Extreme Winds on Mount Washington

2022-04-12 12:03:50.000 – Adam Muhith, Summit Intern

A range of the anemometers designed and used during the Observatory’s history, shown above clockwise from top left, include the Heated No. 2, Grandfather Pitot, Pitot 92, Pitot 94, Pitot 97, Pitot 11, and Pitot 19.

Today is Big Wind Day, commemorating the 231 mph wind gust recorded by Mount Washington Observatory staff on April 12, 1934.

Since the earliest days of observing weather on the summit, measuring wind speeds has been a challenge. Heavy icing conditions and extreme winds are enough to damage common measurement devices, rendering them inadequate for maintaining our 90 years of continuous weather and climate data. In the early years of the Observatory, the necessity arose to have an instrument that could accurately measure high winds and maintain accuracy during severe icing.

To this day, there are no commercially available instruments that could survive a Mount Washington winter, let alone accurately measure wind speeds throughout the cold season. To combat this, MWOBS has accomplished numerous innovations in measuring wind speeds through the development of heated anemometers. Adding a heater allowed for these instruments to survive the summit’s icing conditions, and the Observatory has spent the decades since improving and perfecting a custom designed heated pitot anemometer.

Beginning back in the late 1800s, the Blue Hill Observatory originally loaned some cup anemometers to the Observatory, beginning a record of wind speeds. However, these anemometers were non-heated, preventing a continuous record in the wintertime icing conditions. The cup anemometers remained in use as primary instruments through 1946. From then until 2005, the Observatory used them occasionally as backup anemometers in light wind and light icing conditions.

Attempts to overcome icing conditions led to the development of a heated anemometer, aptly named the Heated No. 1. With a new heating element, this anemometer could counter winter ice accumulation. Implemented on Nov. 9, 1932, Heated No. 1 was able to take measurements when winds were between 11-120 mph in icing conditions.

After it went up, efforts to improve Heated No. 1 resulted in the Heated No. 2 becoming an operational instrument. Heated No. 2’s improvements over No. 1 included a sheltered heater with a vent around the shaft, a 700-watt double-circuit heating device, and vacuum contacts for electrical recording.

Heated No. 2 became the main instrument on the summit in 1933, replacing Heated No. 1. Heated No. 2 is most famous for recording The Big Wind of 231 mph on April 12, 1934, which still stands as the fastest surface wind speed ever observed by a human. Measured in extremely challenging icing conditions, the measurement was extensively verified, setting the standard of data quality for MWOBS weather observers throughout our history. The Heated No. 2 is currently on display in the Extreme Mount Washington™ museum on the summit.

Shown above are Mount Washington Observatory staff Alex McKenzie, left, John Dick, and Aubrey Hustead, holding the Heated No. 2 Anemometer.

Later on into the Heated No. 2’s lifespan, questions emerged surrounding its performance in periods of high winds and heavy icing. Beginning in the winter of 1944-45, testing for using an operational pitot tube anemometer began. The idea for using a pitot tube was borrowed from the aviation industry, since pitot tubes were proven to be able to measure wind speeds much faster than those experienced on the summit. The tubes were attached to the nose and wings of an airplane, analyzing the free-air pressure and the measured pressure at the plane, and then calculating the relative airspeed from the difference.

The tubes themselves were commercially available, so once determined that a pitot tube could properly measure wind speeds on the summit, all that was necessary was to build the housing. Observatory staff got creative and constructed a mast and skirt out of a repurposed tin vegetable can. With these, in 1946 the Grandfather Pitot became the Observatory’s main instrument for measuring and recording wind speeds. Its advantages over the Heated No. 2 included that it automatically corrected the barometer to free-air pressure, had no moving parts, and could accurately measure instantaneous gusts and average sustained wind speeds directly from the recorder. Previously, observers would calculate these two data points by hand.

The Grandfather worked well for speeds above 30 mph, but winds less than that often could not deliver the torque necessary to vane the tube into the right direction. In these instances of lighter winds, using the cup anemometers as backups came in handy. The Grandfather was then retired in 1992, and, through 2022, remains the summit’s longest-used primary anemometer.

In 1990, the “Pitot Project” began, looking to build a replacement for the aging Grandfather. Primary goals of the project were to simplify maintenance and implement newer technologies to upgrade performance. The Pitot Project developed four similar pitot tubes used through the 1990s and 2000s – Pitot 92, Pitot 94, Pitot 97, and Pitot 99. Respectively, these pitots were functional instruments on the summit during 1992-2000, 1994-97, 1997-2011, and 1999-2011.

Pitot 92’s design process focused on building the heated vaning assembly. It featured an improved heating system capable of fully automated and ice-free operation and custom-machined aluminum body parts alongside other commercially available components. These allowed for modular design and easier standardization of repair processes.

Pitot 94 then included a new and improved heater control system, as well as a custom chart recorder interface for the Observatory’s wind direction instrument. The design improvements built a linkage between the wind direction instrument and the Pitot 94, thereby eliminating the need for one of the wind vanes. MWOBS used Pitot 94 primarily as a backup for Pitot 92. In the summer, the Observatory used the Grandfather Pitot as a backup as well.

As the Pitot Project continued, the Observatory analyzed various retired pitots and identified instances of inconsistent performance and calibration. Observers found very slight variances in wind direction and speed from one pitot to the next, although each measurement was within reasonable margin of error. Observers looked to ensure that all measurement tools on the summit remained consistent to one another.

Measures to rebuild Pitot 94 birthed the Pitot 97, which had a new heater controller subsystem, weather room display and control subsystem, pressure transducer, and data subsystem. When implemented, Pitot 97 was the primary means of accurately measuring winds up to 250 mph in any conditions. The Observatory then later rebuilt the Grandfather Pitot as the Pitot 99, serving to supplement Pitots 92 and 97 as summer and light icing backups.

In the 2000s, new technologies and instruments arose. Beginning in summer 2005, the Observatory has used various RM Young propeller anemometers for wind speeds below 30 mph with light-to-no icing conditions. The RM Young models replaced the use of cup anemometers. RM Young wind monitors are now used in conjunction with the pitot system throughout the summer months.

An RM Young propeller-driven anemometer.

As time went on, Pitots 97 and 99 began to show their age. Work began to develop new pitots to replace the models. Pitot 97, the main instrument, had begun to experience recording issues before the Observatory was able to replace it. In this instance, Pitot 99 and an unnamed backup pitot served as the main recording devices.

Early in January 2011, work on the Pitot 11 concluded. Pitot 11 went up as Pitot 97 came down, and Observatory staff found that Pitot 97’s housing contained about a cup of water, the pressure line became disconnected, and there was significant corrosion on the wires. Pitot 11’s improvements over 97 included new heat tapes, a heated tube, and new insulation. Pitot 11 served as the Observatory’s main instrument through 2017, when Pitot 17 took its place.

Pitot 17, referred to as the “sister” to Pitot 11, is structurally identical to Pitot 11, with improved skirt heaters and bearings. In 2019, Pitot 17’s bearings needed replacement, so Pitot 19 took its place. Pitot 19 is again a sister pitot to Pitot 11, structurally identical to the prior two pitots. Pitot 19 included repaired bearings and features to enhance heating and to simplify data transmission. Pitot 19 is currently in use on the summit, functioning as the current primary pitot and air pressure measurement device.

In April 2013, a group of UMass Lowell students published a paper analyzing certain factors and their effect on the Observatory’s wind speed measurement system: tubing length between the transducer and pitot tube, system leaks, and the pitot tube’s angular orientation. They concluded and recommended to the Observatory to shorten the tubing length, implement methods to minimize leak zones, and to maintain the current pitot tube angle and mount. With these recommendations, work began to develop the Pitot 22.

Conceptualized as the next generation of pitot anemometers, Pitot 22 resulted from a multi-year collaboration between MWOBS, General Electric, and UMass Lowell. Its improvements include a more simplified design for easier removal and installation, shorter tube length, improved gust sensitivity, and an upgraded heating system. Construction began in 2015, and Pitot 22 was first installed on the summit in August of 2018, having been recently reinstalled in January 2022 after third-party testing from the University of New Hampshire. Currently, MWOBS is in the final stages of testing before designating Pitot 22 as the primary wind measurement instrument.

The Pitot 22 Anemometer.

Adam Muhith earned a B.S. in Environmental Engineering from the University of Texas at Austin in 2021. He joined our summit team as an intern in fall 2021.

Adam Muhith, Summit Intern

An Uncommon Commute to Study our Weather and Climate

2022-03-23 14:27:15.000 – Jackie Bellefontaine, Weather Observer and Education Specialist

One of the most common questions I’m asked as a Weather Observer is how my colleagues and I get to work. The logistics of getting up and down Mount Washington change depending on the season and conditions. We have several vehicles, including a van, truck, and Bombardier snowcat. The snowcat is definitely the standout vehicle that people are most curious about – understandably so!

The snowcat is similar to the groomers at ski resorts, with large tank-like treads and a plow on the front. But the Mount Washington Observatory snowcat is outfitted with a cab on the back that fits up to a dozen people and is used for getting observatory staff up to and down from the summit during the winter months.

Weather Observer and Meteorologist Jay Broccolo keeps an eye on blading from the snow cat cabin window during an early March trip to the summit for our weekly shift change.

A typical snowcat ride starts at the base, given that there’s enough snow to go straight from base to summit. If the road is only partially covered with snow/ice, our van or truck with chains is used to take our staff part way up the road to where the snowcat is staged for the rest of the journey. When starting with the snowcat at the base, we load up the cab and side saddles with gear and groceries for the week. Then we climb aboard and the snowcat operator starts our trek up to the summit. A typical snowcat ride from base to summit takes about an hour and a half, but that’s with ideal conditions such as minimal snow drifts and good visibility. And Mount Washington isn’t exactly known for ideal conditions.

Snow drifting along the lee side of Mount Washington along the auto road.

Due to large amounts of snow blowing over the summit and down the lee side of Mount Washington (think of all the snow that lands in Tuckerman Ravine), there are often large snow drifts on sections of the auto road that require blading, sometimes LOTS of blading. This blading (plowing) means continuous back and forth travel as drifts are cleared from the road, which isn’t great for those with a queasy stomach. Occasionally, a section of the road may require so much blading that the operator will stop to let the passengers out for fresh air and a break – if conditions are safe to do so – from the back and forth.

Observatory staff and guests from WBZ CBS Boston walk along the along the Mount Washington Auto Road as the snowcat clears the way

Large snow drifts, especially combined with other undesirable conditions such as low visibility, can make for a much longer trip up to the top (several hours!). There have also been occasions when visibility was so poor from fog and blowing snow that the snowcat had to turn around and return to the base to try again another day.

On long snowcat journeys, we spend our time catching up with colleagues on projects and what we did during our week off the mountain before silence settles in and everyone, or mostly everyone, falls asleep in the heated cab. Depending on the conditions, stops are occasionally made at an Mount Washington Regional Mesonet site or two to perform maintenance such as digging out solar panels from the snow.

The snowcat traveling up the auto road on a bluebird day.

Upon arrival at the summit, the current crew of observers and interns meet the snowcat at the door to start shift change by unloading gear. The crew in the snowcat begins to gather gear, or shoot out of the back of the snowcat as soon as the door opens, racing to the restroom (which is a situation I find myself in often). The now downbound crew loads up their gear, trash and laundry before joining the crew that just arrived in the weather room for shift change. Once information and maybe a few jokes are exchanged between shifts, it’s time for the downbound crew to say goodbye to Nimbus for the week and climb aboard the snowcat for a similar ride down. At the base, observers once again unload the snowcat before heading home for the week and coming back for another adventure up the road!

The snowcat loaded up with gear outside of the NH State Parks’ Sherman Adams Summit Building.

Jackie Bellefontaine, Weather Observer and Education Specialist

Brrrrr, It’s Cold Outside, but the Rime Ice is Beautiful!

2022-03-15 14:34:34.000 – Matthew Addison, Weather Observer/Meteorologist

It’s been four months since I arrived at Mount Washington and wow, has it been chilly! In my 26+ years as a meteorologist, I can say this has indeed been the coldest weather I’ve ever experienced.

Of 147 days on the summit, only 28 have seen the temperature rise above freezing, which means it’s been below freezing 81% of my time here. While that may not seem too bad for most New Englanders, as a native Texan, this is a bit chilly.

While I do love the cold, it’s the wind that makes the temperature almost unbearable at times. During the same 147 days, the winds were blowing at or greater than hurricane strength (74 mph or higher) on 76 days, or 52% of the time. This has made wind chill temperatures dip to the lowest I’ve ever experienced in my lifetime.

As you may already know, the wind chill is how cold temperatures actually feel on your skin when wind is factored in. The wind chill temperature, as defined by the National Weather Service, is based on “the rate of heat loss from exposed skin caused by wind and cold. As the wind increases, it draws heat from the body, driving down skin temperature and eventually the internal body temperature.”

Even when properly dressed for very cold temperatures, when the wind is at or above hurricane strength, wind chill temperatures can dip to extremely dangerous levels and cut right through whatever it is you’re wearing. This past Valentine’s Day on the summit was the coldest day so far for me. We bottomed out at -24 °F with winds of 70 mph, providing a wind chill of -70 °F. I’ve experienced colder ambient temperatures before, but never a wind chill this low.

Winter days can create such beautiful landscapes across the White Mountains, whether it’s a new coating of snow that fell overnight or the aftermath of a night of freezing fog. With cold temperatures as common as they are on the summit, when you combine the subfreezing temperatures with foggy conditions you can get some amazing icing formations (in 2021, we had 321 days with at least some amount of fog recorded during a 24-hour period).

Rime ice and hoar frost are by far the most spectacular things I’ve witnessed on the summit. While hoar frost is not typically a hazard, rime ice can be extremely dangerous for aircraft. But as an observer, it’s just absolutely stunning to watch ice form throughout the night.

Rime ice forming on rocks.

According to the National Weather Service, rime ice is an “opaque, or milky white, deposit of ice that forms when small supercooled water droplets accumulate on the leading edges of objects that are at or below freezing.”

“Supercooled water droplets will freeze completely and quickly without spreading from the point of impact. Thus, the droplets retain their spherical shape as they freeze, creating air packets between the frozen particles. This process creates an irregular shape of the ice.”

Hoar frost is “a deposit of interlocking crystals formed by direct sublimation on objects, usually those of small diameter freely exposed to the air, such as tree branches, plants, wires, poles, etc. The deposition of hoar frost is similar to the process by which dew is formed, except that the temperature of the frosted object must be below freezing. It forms when air with a dew point below freezing is brought to saturation by cooling.”

Hoar frost and rime ice typically occur when fog from low-lying regions, accompanied by high winds, is blown uphill into the mountains. As fog rises and cools, its airborne water droplets cool to sub-zero temperatures without freezing. As the windborne drops make impact with objects, they immediately freeze and accumulate on each other, building towards the direction of the wind.

Here on the summit, rime icing and hoar frost formation happen almost daily during the winter months. Most days, the icing can grow up to three inches per hour. However, I’ve witnessed it growing over five inches per hour during our most intense weather events.

Below are some of my favorite photos I’ve taken of rime ice forming on different objects at and near the summit.

Rime ice forming on a grade stake along the Mount Washington Auto Road.

Rime ice on the observation deck railing.

Rime ice on the RM Young anemometer.

Rime ice is visible looking out our weather room window.

Hoar frost on a temperature sensor.

I’m sure you can agree with me, rime ice can be a beautiful weather phenomenon to view up close. Knowing and reporting icing is an important part of being a weather observer. It’s crucial to keeping the aviation community safe. Additionally, icing can be very destructive to meteorological instruments. It can encapsulate anemometers and other meteorological instruments and if enough icing forms, this, in combination with high winds, can destroy the equipment.

Since icing forms frequently here at the observatory, we must remove it from our weather equipment hourly to ensure not only our weather observations are as accurate as possible, but to prevent any damage to the very costly sensors.

If interested in learning more about all different type of icing, I recommend visiting this link from the National Weather Service.

Thanks for reading!

Matthew Addison, Weather Observer/Meteorologist

February 2022 by the Numbers

2022-03-07 11:42:52.000 – Ryan Knapp, Weather Observer/Staff Meteorologist

March has arrived, so it’s a perfect time to look back and summarize February. A few words I would use to summarize February’s weather conditions on the summit are warm, foggy, and windy. Let’s look back at some of the stats for the month.

Our average temperature for the month was 8.1°F (-13.3°C), which is 2.2°F above the 1991-2020 30-year climate normal for our station. Our warmest temperature recorded in February was 38°F (3°C), occurring on Feb. 18. Our coldest temperature recorded during the month was -24°F (-31°C) on Feb. 14.

In terms of total liquid equivalent precipitation (the liquid collected from rain and by melting the freezing and frozen precipitation types collected after measuring their depth) during February, the summit of Mount Washington received 4.65 inches, which was 0.80 inches below the 30-year normal for our location. The summit received 32.7 inches of snow/sleet, which was 10.6 inches below the 30-year normal.

We’ve received several questions recently about how our snowfall has been doing at the summit. For Mount Washington, our snowfall season goes from July 1 to June 30 (all year!), so our season is far from over. Looking at the numbers from July 1, 2021 to Feb. 28, 2022, the summit has received 167.8 inches of snow/sleet, which is 20.5 inches below the 30-year normal for our location.

That deficit might seem like a lot, but it can still easily be made back up. Statistically speaking, March is our second “snowiest” month, and we will also typically see snowfall in April, May, and even early June. According to the 30-year normal from March 1 to June 30, we can still receive upwards of 93.5 inches of snowfall. So, yes, we are down but far from out.

In terms of winds during February, our average was 45.4 mph, which was 0.8 mph above the 30-year normal for our location. Our highest gust recorded during the month was 125 mph, occurring on Feb. 19. February had 19 days with gusts of 73 mph or greater, and of those days, nine had gusts that were 100 mph or greater.

As for our weather during the month, we averaged 36% of the possible sunshine. The summit had one day that was noted as clear or mostly clear, and there were three partly sunny days, with the remaining 24 days being filed under mostly cloudy, cloudy, or obscured (fog). We had 26 days with at least some amount of fog recorded during a 24-hour period. We had four days with rain/freezing rain and 20 days with snow/sleet.

If interested in additional weather data, please check out our F-6 page (updated nightly), our Normals, Means, and Extremes page, our Current Conditions page, and our 48-Hour Higher Summits Forecast. If you need data for research purposes, you can submit a request here.

If you value our high-quality data set spanning almost 90 years, consider a donation to Mount Washington Observatory, a private, nonprofit institution. Donations from members and corporations are an important source of funding that directly support the continuation of forecasting, climate data, and educational work at the summit of Mount Washington.

Sunrise with undercast conditions on 22 February

Ryan Knapp, Weather Observer/Staff Meteorologist

Observatory Staff and Interns Present Projects at AMS Annual Meeting

2022-03-02 05:56:17.000 – Brian Fitzgerald, Director of Science & Education

Mount Washington Observatory staff and interns presented two research posters and an overview of our WeatherX curriculum development project during the 102nd American Meteorological Society’s (AMS) Annual Meeting, held virtually in January.

After planning an in-person meeting in Houston, the AMS made the tough call to change course and host an all-virtual meeting due to the Covid-19 surge earlier this year. Many across the AMS community expressed support of this decision for the cause of health and safety.

Our staff attended a variety of the virtual presentations throughout the week of Jan. 23-27 as part of professional development. In addition, thanks to our successful topic proposals last year, the AMS invited MWOBS to present the following two research projects and one education project.

Project Title: A Data Exploration of Visibility at Mount Washington Observatory (1943-2020)

Presented by Weather Observer and Meteorologist Jay Broccolo. Download poster.

The main goals of this project were to 1) explore the availability and quality of visibility data on Mount Washington and 2) conduct an initial analysis to determine what, if any, trends were apparent since 1943.

All available visibility data were extracted from our summit database to determine what might be available for analysis. The data were compiled into groupings such as seasonal averages and counts of 100 miles or greater observations and then plotted over time.

Overall, a general increase in visibility has been reported since continuous visibility records started at MWOBS, using a proxy recorded visibility called lowest visibility, which is derived from prevailing visibility.

To continue this research, prevailing visibility should be digitized for analysis, and statistical decadal comparisons should be made. Findings should also be assessed against changes in prevailing wind direction and air quality data. Additional information is available on our current projects page.

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Project Title: A Comparison of Climate Normals across the Mount Washington Valley, New Hampshire (1981-2010 and 1991-2020)

Presented by Jay Broccolo and Summit Interns Michael Brown and A.J. Mastrangelo. Download poster.

Our 2021 summer interns completed a project examining climate data for the Mount Washington region. The group examined monthly temperature, precipitation, and snowfall data released from the National Centers for Environmental Information (NCEI) for three local weather stations over the two latest 30-year observation periods, 1981-2010 and 1991-2020.

The recorded differences between the two datasets were used to create several visuals to best describe the changes at the three locations since 1981.

Across the three stations, located at the summit of Mount Washington, the Pinkham Notch Visitor Center, and in North Conway Village, a general warming trend was observed between the two datasets. Additionally, while the summit station recorded less annual precipitation, the other locations observed increased rainfall. Finally, all three locations recorded higher annual snowfall values; in addition, a general increase in the snowpack duration was observed.

Of particular interest to the group was an increase in late winter snow at the North Conway and Pinkham Notch stations, possibly signaling a shifting snow season.

Future research endeavors to extend the findings of this project, as recommended by the interns, include investigations regarding the mountain’s rain shadow effect, North American snow seasonality, local urban heat islands, and changing storm tracks as four. More information is available in this article.

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Project Title: Understanding Weather Extremes with Big Data: Inspiring Rural Youth in Data Science

Presented by Director of Science & Education Brian Fitzgerald. View presentation.

Mount Washington Observatory, along with colleagues at the Education Development Center (EDC), Concord Consortium, and the universities of Maine and Washington, have teamed up to develop curriculum called “Understanding Weather Extremes with Big Data: Inspiring Rural Youth in Data Science,” or WeatherX for short.

Using extreme weather data from NOAA and MWOBS, rural middle school students gain skills in data analysis and computational thinking, while also learning about scientists who gather and use this data in their day-to-day professions. A significant focus of the WeatherX materials is on making career connections that help inspire students to pursue STEM careers.

As part of the 31st Conference on Education highlighting the career connections approach and results, Fitzgerald also spoke about the “Chat with a Scientist” part of WeatherX. Participating classrooms learn about the life and work of our weather observers through pre-recorded video and observer biographies, culminating in a live virtual connection. Students interview our scientists during these “chats” with prepared and off-the-cuff questions, resulting in students learning about who “scientists” are, what motivates them, and what pathways they’ve taken to a unique career in meteorology.

To learn more about this project, visit our WeatherX page.

We look forward to sharing our work and connecting with colleagues again at AMS’ next Annual Meeting, scheduled for Jan. 8-12, 2023 in Denver.

Brian Fitzgerald, Director of Science & Education

A Look Back at the Feb. 18 Rapid Temperature Drop

2022-02-22 16:21:30.000 – Jay Broccolo, Weather Observer and Meteorologist

It was like this. The temperature was holding steady at around 38°F on Friday, Feb. 18. The station had just tied the record high temperature for the day. Winds were out of the west/southwest with sustained winds in the 70 to 90 mph range, and it was raining out. The beautiful snowpack that took all winter to build… we watched a lot of it melt away. Jackie had to trudge through a foot or so of slush to get the precipitation can that morning. It was rather messy.

Then, the winds suddenly relaxed and the temperature started to drop. We knew there was going to be a steep decline, given the synoptic set-up. The White Mountains seemed to be at the bottom of the Low’s center as it crossed through the region, which aligned with the bottom of the trough aloft.

As the cold front crossed through, wind direction shifted 20 degrees to the north, making it westerly. It took one hour for the temperature to drop 18 degrees, as seen below in figures 1 and 2.

Figure 1: Six-hour temperature (°F) at KMWN. Note temperatures at 0630 EST of 38°F.

Figure 2: Six-hour temperature (°F) at KMWN. Note temperatures at 0730 EST of 19°F.

At 0630 EST, the temperature was 38°F (rounded). Over the next hour, the warm front abated, and the pressure bottomed out at roughly 780 hPa, signifying the passage of the trough and that the cold front would be quickly approaching. The night prior, we looked at the weather prediction models to see if our forecast had changed, which it had not really, but we did see that the models were trending towards a stronger cold front. In figure 3, you can see the 00Z model run for that day. The strong cold front and frontogenesis were projected to pass between 0600 and 0700 EST, along with the bottom of the trough as depicted by the wind barbs.

Figure 3: 2022 02 18-00Z NAM 3K 850-hPa Temperature advection (°K/hr), frontogenesis (°K/100km/3hr) and wind barbs (direction and speed in knots).

The cold front actually began to sweep through, at summit level, at 0631 EST. Around 25 minutes later, the temperature dropped 16°F, then another 2 or 3°F over the next half hour. Figure 4 also shows the intensity of the front. The dark blue color part of the cold front was likely just east of the summit by 0800 EST.

Behind the front, cold air advection was much less and presented as a more gradual slump in temperature rather than the plunge that occurred initially. The weather prediction center also puts out a synoptic surface analysis overlayed on an infrared satellite image. Figure 4 (below) shows the frontal boundaries and surface isobars (lines of equal pressure) from the associated event. Evaluating the isobars and position of the frontal boundary indicates two distinct air masses on either side of the front. Flow tends to follow the isobars and by the looks of this surface analysis, it seems as though the wind shift at the surface was more profound than it was at the summit.

Figure 4 also shows the satellite imagery. The cloud cover and temperature colder cloud top temperatures seen to the east of the front is another indicator of the different air masses.

Figure 4: 2022 02 18-1200Z Surface analysis and infrared satellite imagery.

We constantly watch satellite imagery and radar when precipitation is around to observe what occurs in the atmosphere. It is intriguing to then experience it and follow data from our mesonet, summit instruments, and real-time observations as systems pass through the White Mountains.

Figure 5: Weather Observer and Education Specialist Jackie Bellefontaine’s footprints frozen from refreeze of waterlogged snow.

Until next time…

Jay Broccolo, Weather Observer and Meteorologist

Love Is in the Air…and So Are Clouds!

2022-02-14 13:37:41.000 – Sam Robinson, Weather Observer/Engineer

Today is Valentine’s Day, so I thought it would be fitting to focus on what I love most about being a weather observer… clouds! Up here on the summit, we get to view clouds almost non-stop, and it is very rare when we can report “SKC,” or “sky clear.”

Due to our unique location and elevation, and the fact that clouds are up in the sky, sometimes we are able to view clouds over 200 miles away! So in order to report “SKC,” there cannot be any clouds over basically the entirety of the northeast, the northwestern Atlantic Ocean, or even southern Quebec. While our horizontal visibility is limited to about 130 miles due to the curvature and topography of the earth, our visibility out and up can be much greater. The only things that limit it then are airborne particulates and, of course, other clouds.

Described below are some of my favorite common clouds that we view up here, as it would take much longer to explain all cloud types, their characteristics, and how they form. However, if interested in learning more about all of them specifically, I recommend these links from the National Weather Service: https://www.weather.gov/lmk/cloud_classification

https://www.weather.gov/jetstream/clouds_intro

https://www.weather.gov/jetstream/basicten

My personal favorite are cirrus, part of the cirri-form cloud classification, or high cloud family. These form at the highest parts of the atmosphere (usually 20k to +40k feet above ground level) and are made up completely of ice crystals, rather than water vapor, even in the summer. Cirrus clouds are usually the first sign of incoming moisture ahead of approaching systems, and are also usually the first and last clouds to be viewed at dawn and dusk. Because they are so high up in the atmosphere, the rising/setting sun illuminates them before/after it crests the horizon and this is usually what leads to magnificent sunrises and sunsets.

During the day, cirrus clouds usually appear thin, fibrous, and mostly white in color except near the horizon line where they look slightly yellowed due to a greater distance and thickness of air between the clouds and viewer. They also tend to move slower across the sky than other cloud types due to their greater distance from the viewer.

Here are a few pictures I have taken, featuring cirrus/cirri-form clouds. You may be able to spot some cirrostratus or cirrocumulus clouds in these pictures as well. These are part of the same high cloud family but cirrostratus is a denser and usually thicker blanket of cloud high up in the atmosphere, while cirrocumulus can form slightly lower and tends to be puffier looking or speckled in appearance, with fibrous edges.

Cirrus clouds as seen over my backyard in north central Massachusetts.

Cirrus clouds over Pack Monadnock Mountain in southwestern New Hampshire.

Cirrus clouds over western MA, as viewed from the summit of Mount Wachusett in north central MA.

Sunset illuminating cirrus clouds to our west, as viewed from the summit of Mount Washington.

My next favorite cloud is the cumulonimbus, part of the cumulus cloud classification, or low cloud family. These clouds tend to be thunderstorms and are formed when very strong upward motion grows the clouds very high into the atmosphere. The uppermost reaches of cumulonimbus clouds can actually spread out to form cirrus clouds, and when the cloud reaches this high, lightning and hail tend to form as well (because remember, cirrus clouds are ice crystals, and lightning and hail come from ice crystals).

Cumulonimbus tend to form only during the summer in our region because atmospheric conditions need to be just right with very warm air at the surface and cold air aloft. The warm air wants to rise and the greater the gradient, the faster and higher these clouds and storms will form. Sometimes these clouds can have a base only a few thousand feet off the ground but the height reaches over 60k feet up into the atmosphere!

The signature anvil top is usually a telltale sign of a cumulonimbus cloud due to stronger winds aloft shearing off the top of the cloud quicker than at lower levels. Here are a few pictures of cumulonimbus clouds that I have taken.

A cumulonimbus cloud at sunset to our west over Vermont. Cirrus may be viewed at the very top.

A far distant cumulonimbus to our southwest over southern MA, as viewed from the summit.

A picture-perfect cumulonimbus with signature anvil top over central MA.

Another textbook cumulonimbus with anvil top over southwestern NH, as viewed from north central MA.

Rounding off my top three are regular old cumulus clouds. They appear puffy, usually friendly looking (compared to the ominous cumulonimbus), and are usually mostly white in color, only graying as they become thicker. They tend to look like cotton balls and can be all different shapes and sizes, which can also vary quickly depending on the conditions aloft. If you have ever laid down in the grass (or snow) and stared up at ever-changing cloud shapes trying to make them out to be real objects, chances are these were cumulus clouds.

Cumulus clouds are sometimes called diurnal cumulus because they form as the sun comes up, and starts to heat up the lower levels, and then dissipate as daytime heating is lost. These clouds can form during all seasons and tend to form anywhere from a few hundred feet off the ground up to around 6k feet. They are also sometimes referred to as fair weather cumulus because even on mostly sunny, fair weather days, if there is just enough low-level moisture and lift, they will form. I enjoy these clouds because they tend to have character and a lot of times look like the typical image of a cloud if one was to hear or read the word (stereotypical clouds in cartoons, clip art, and even emojis are cumulus).

Cumulus clouds can also form stratocumulus standing lenticular clouds, which are a very popular cloud type due to their unique, flying saucer-like shape. Lenticulars can actually form at all levels of the sky but tend to share the same general shape. These unique cloud formations are shaped when air moves over hills or mountain ranges, so we often view them up here at the summit. I have attached a few pictures that I have taken of fair weather cumulus clouds, as well as some lenticulars (although some of these lenticulars may be altocumulus standing lenticulars [mid-level] or cirrocumulus standing lenticulars [high level]).

Diurnal cumulus to the east, as viewed from the Mt. Washington Auto Road.

Fair-weather cumulus over the Great Gulf, to the north/northeast, as viewed from Clay Col.

A stacked stratocumulus standing lenticular (SCSL) over our observation deck.

Stacked lenticulars (altocumulus standing lenticulars [mid-level] spanning up to cirrocumulus standing lenticulars [high-level]) to our south over Lake Winnipesaukee.

Knowing about clouds is an important part of being a weather observer and crucial to observations in order to keep the aviation community safe, since pilots are flying among them in the sky. Clouds can also tell an important story of incoming or departing weather, which is especially helpful if in remote locations where forecast information is limited or unavailable. Observing and identifying clouds has been a favorite hobby of mine for a few years now. An interesting truth is this is one aspect of my job that I can practice even during my off weeks, no matter my location.

At any given time, and at any given location, there are usually some clouds up in the sky to look at. Like many weather-related phenomena, the sky condition over our heads is almost always changing and rarely ever looks identical from one point in time to the next (except clear or overcast skies, I suppose!).

That is all I have for this time, I hope you enjoyed reading this and I look forward to writing my next blog again soon!