07:11 Tue Jul 17, 2018
One Cloud to Cover Them All
Every meteorologist has a favorite cloud type, for most people this has something to do with severe weather. I get it, supercells are really cool and exciting and give conditions where you can see really unique clouds like pileus or mammatus. These clouds are too rare and energetic for me. Give me a nice stratus deck any day and I’ll be happy, better yet, layered decks. There’s just something so comforting and peaceful about a smooth ocean of white. A stratus day is a good day. If I’m on the mountain I can watch the deck slowly drift over and around the peaks and change shape as it flows. Off the mountain I can sit at home and read a book or watch the rain fall on the windows and leaves. Either way, I can easily clear my mind and unwind.
I took the picture above back in June after the summit cleared out of the clouds from rain overnight. This stratocumulus deck was so detailed and had beautiful smooth streaks imbedded in the deck.
This sunset was one of the prettiest I’ve seen up here on the summit. The sky wasn’t terribly red, but there was such a pretty deck off to the east and the haze made the mountains various shades of indigo. It was framed to beautifully.
I took the two images above this week on Saturday morning before the summit went into the clouds. The first one shows the eastern expanse of a stratus deck to the south spilling over Wildcat. The second image was taken to the west showing the same deck looking out over the southern Presidentials.
Sarah Thunberg, Summit Intern
18:09 Sun Jul 15, 2018
Where is the Wind this Week?
The Mount Washington Observatory’s claim to fame has long centered on wind, with the observatory seeing the highest wind gust ever (recorded by man) at 231 mph on April 12th, 1934. And at an average annual wind speed of 35 mph, the observatory has the highest average wind of any station in North America. And it’s personally given me by far the strongest wind’s I’ve experience in my life, with gust’s over 90 miles an hour on previous shifts. But so far this shift, the mountain has not lived up to its reputation as the home of the world’s worst weather.
Average daily wind speed for the shift so far according to the RMYoung Wind Speed and Vane Instrument
Although these winds may not be the ‘extreme’ that people expect from Mount Washington, in truth, it's not unprecedented at all. On Mount Washington, the northeast, and the northern hemisphere more broadly, winds tend to drop off in summer as compared to winter.
Mount Washington’s average monthly wind speeds in mph (mountwashington.org)
The summer the wind speed average, in miles per hour, hovers in the twenties, which is well below the average of 40s in the winter months. This substantial difference is largely due to a changing temperature gradient.
Image from the North Carolina Climate Office showing seasonal movement of the polar jet
The temperature gradient between the equator and the poles decreases significantly from winter to summer. This in turn causes the polar jet, which is located far to our south in the winter (Generally around 40° N) to weaken substantially and retreat far up into Canada.
Jet Stream separates cold and warm air masses (nasa.gov)
The polar jet stream normally acts to separate the cold air mass from the warm air mass. But as it weakens and moves north, the division between cold and warm, as well as between high and low pressures, decrease. Wind is simply the flow of air away from a high pressure or towards a low pressure. When the gradient of the pressure decreases, the speed air flows also decreases. So although our summers are still windy compared to other locations in the region, the weakening summer hemispheric temperature gradient makes them more mild, especially compared to the mountains winter’s, when the wind frequently gusts over 100 mph. These calmer conditions make summer an ideal time to come up to the summit for a hike or visit.
This is not to say that extreme winds never happen on Mount Washington in the summer. All visitors should always be prepared for harsh weather, even in summer. An example of strong summer winds was July 20, 1996, when the wind gusted up to 154 mph. However, these powerful winds normally need a powerful external trigger in the summer, such as a tropical system moving north into New England, or a line of powerful thunderstorms passing through the White Mountains.
Griffin Mooers, Summit Intern
18:19 Sat Jul 14, 2018
Mount Washington Sunsets
When I woke up 5am Wednesday morning for shift change, my first thought was that I couldn’t wait until my next off week so I could finally sleep in. Once I got back to the top, however, I quickly forgot why I would ever want to leave. The cool air is an amazing reprieve from the summer heat in the valleys and the views of the surrounding towns, forests and mountains are unmatched. Whenever I’m up here, my favorite part of the day is without a doubt sunset. As day progresses into night, the mountain is transformed from a bustling tourist destination to a quiet, serene mountaintop. Additionally, I was able to witness a few amazing sunsets so far this week too.
On Wednesday a perfect amount of altocumulus clouds were illuminated by the sun setting on the horizon. Looking toward the southeast, I also saw some anticrepuscular rays caused by the shadows of the altocumulus. The rays are actually parallel, despite appearing to converge because of an optical illusion created by the increasing distance.
Wednesday’s sunset and anticrepuscular rays
Thursday’s sunset was slightly subdued by distant clouds. However, some remnant smoke from wildfires in Siberia caused the sun appear as a faded red ball, even somewhat resembling the appearance of Jupiter.
Clouds approaching the summit from the West cut the sunset short Friday evening, but the view was still amazing with the sun illuminating some fog passing near the summit.
The summit has returned to the clouds today, so it looks like there won’t be much to photograph tonight, although I’ll have my camera ready for whenever we do clear out of the clouds again.
Simon Wachholz, Summit Intern
07:34 Wed Jul 11, 2018
'Tis but a Patch!
Living on a mountain has its ups and downs (literally), and Mt. Washington is no exception to that. Acclimated to our unique and isolated workplace, we often find ourselves captivated by things that other people would think odd.
For instance, when we aren’t in the clouds, we have our fair share of spectacular sunrises and sunsets. So many in fact, that after a while they also become commonplace. While we still go out to the observation deck to watch them, we have begun to judge their magnificence more critically.
In contrast, there are some objectively insignificant things that have our captured our full attention. One of these things in particular, the one I intend to write about, is a patch of snow on one of our neighboring summits.
This snow patch, better known as the Jefferson snowfield, is well known by summit staff, hikers, and skiers. Most snow on the summit of Mt. Washington and the Northern Presidentials tends to melt away by mid-May, but the snowfields hold on a bit longer. Initially covering the eastern slopes of Mt. Jefferson, during summer the snowfields begin to dwindle until only a single snow patch remains.
The remaining patch of snow on Jefferson during the month of June
A few weeks ago, as an annual tradition, summit staff started making guesses as to when the patch would melt away completely. As the day drew near, and the snow patch nearly disappeared from view, I took it upon myself to confirm its condition. I left as soon as possible, getting up before sunrise so that I might be able to reach the snow patch before it had received too much sunlight.
Sunrise at the Clay Col intersection
By the time I had summited Jefferson, temperatures had risen and the sun was already high in the sky. The snow patch is located in a rocky area alongside Six Husbands Trail. Scouring the rocks, I couldn’t find any snow and I was worried that I was too late. I was about to give up and turn around when I found it. A ten foot long strip of snow was all that was left, and melting fast. I couldn’t help but smile due to my good timing, and the fact that I’d be the last person to visit it.
My emotional reaction during the snow patch’s final hours
I spent a few minutes enjoying the last of the snow on Jefferson, took some pictures, and built a snowman to commemorate the occasion. Unfortunately, there wasn’t enough for a snow angel.
I only had time to build a small snowman (sunglasses for size reference)
Jefferson snow patch has been an undying reminder of winter fun and allowed us to pretend that summer hadn’t really arrived yet. Just before I dumped my water bottle and stuffed it with the last of the snow, I reached the final stage of grief: acceptance. The summer months tend to be calmer and less fun for our observers than winter months, but they deserve acknowledgement too. The snow fields will be missed, but it won’t be long until they return!
If you’re in drastic need of some snow, don’t worry! There is a bit left in Tuckerman’s Ravine. You might want to hurry though, because it’s melting away fast!
Ben Seleb, Summit Intern
15:42 Mon Jul 09, 2018
Special Relativity and Mount Washington
Freshman year, second semester, I took a course called “Introduction to Relativity and Quantum Mechanics” in which we discussed an experiment performed by David Frisch and James Smith in 1963. Frisch and Smith were looking to measure the effect of time dilation on mu-meson particles. Time dilation, an effect of special relativity, basically describes what happens if you throw a clock fast enough: It will start to run slow. The factor of this time change is generally pretty small because it relates the object’s velocity to the speed of light (3*108 m/s). The only way to have a significant time difference is for the object to be moving incredibly fast -- generally around 0.9 times the speed of light.
A mu-meson, also called a muon, is a type of elementary particle that is created by protons from the sun getting broken apart by the atmosphere. These muons have a very short half-life – only two microseconds. If we imagine these muons coming down from the atmosphere, half of them would die in two microseconds, another half in another two microseconds, and so on.
Frisch and Smith wanted to see how fast the muons were travelling, so they set up two stations; one at sea level in Cambridge, Massachusetts, and one at 6,288 feet on top of Mount Washington.
From their experiment, which took about one hour, they found that the muons decayed at only about 0.7 microseconds – if we imagine that the muons were clocks, they would be running slow by a factor of nine. The muons were moving at a speed of 0.995 times the speed of light, which changed how long Frisch and Smith observed their half-life!
This is a very brief overview, and I recommend for more information you take a look at their original paper “Measurement of the Relativistic Time Dilation Using mu-Mesons” (1963) or the short movie Time Dilation: An Experiment with Mu Mesons published by MIT.
The Cosmo Shack, a small wooden cabin on the observation deck of MWO, measures the number of muons that are rained down from the atmosphere and compares it to ones measured at the University Of New Hampshire. This project has been on-going for nearly 60 (!!) years and can be used to monitor ejections of mass from the Sun’s corona as well as solar flares. While the Cosmo Shack is not the same one that Frisch and Smith used, the experiments are similar in their detection parameters.
Emily Tunkel, Summer Intern
06:38 Mon Jul 09, 2018
Back In The Swing Of Things
Hi there! My name is Christopher Hohman, and I am the new Night Observer here on the summit of Mount Washington. Some of you may remember me a few years ago as in intern. I thought I’d spend this blog talking about what I’ve done over the past two years, and what it’s been like coming back to the best place on Earth.
My internship at the Mount Washington Observatory was one of the best experiences I ever had in my life. I had left the mountain on August of 2016 with the fondest of memories, and friendships that would last an incredibly long time. I left with the summit with a heavy heart, but I was ready to get into Meteorology at Plymouth State. The skills I had picked up from various observers, and from all the higher summit forecasts I had done, would end up proving highly valuable to me in the following two years of college.
Thermodynamics, Synoptic Meteorology, Atmospheric Physics, Dynamics, it was all I could ever wish to learn about in life. Sure it felt insurmountable at times with how much work was thrown at me. In the end though, I was able to learn topics that took people thousands of years to understand. I am beyond thankful for the education I have, and that’s why I was ecstatic to graduate this May:
Christopher Hohman, Night Observer
(I’m the dorky looking guy 2nd from the right)
So what’s it been like coming back to the summit? Just as amazing of a feeling as I thought it would be. Reconnecting with the observers, experiencing the hurricane force winds again, and eating the delicious meals the volunteers make for us everyday. I just can’t describe how happy it makes me to finally be back. The weather up here really is as unique as it gets. To have the honor to experience that again on a daily basis, it’s truly a dream come true.
Being the night observer has been a different experience than working during the day. The observatory is a little quieter, there isn’t the constant buzz of noise from the rotonda. It’s a bit darker outside on average, and the fog can make things a little spooky at times. It’s still incredibly fun though, especially when there’s a clear night. The stars up here are phenomenal, you can see the Milky Way end to end:
I really hope to see some unique, and record breaking weather on the rockpile during my time here. My dream is to see the wind record be broken up here again (Perhaps a direct hit from a Cat 5…..). Or even a temperature record or two, I’m not picky! I’m also extremely excited for the winter time to roll around. Summer is great and all, but I’m already ready for some Nor’easters to dump tons of snow on the summit.
No matter how long I stay up here, I know it’ll feel too short at the end of my time. I’m going to enjoy every minute of this, and hopefully my journal entries will be able to entertain some of my kids in the future. I’m beyond thankful for where I am today. I wouldn’t be typing this right now if it wasn’t for my family and friends who given me colossal amounts of support throughout my life.
So here’s to the dawn of my career on Mount Washington. May it be the best experience of my life. Above all though, may it be fun!
07:58 Thu Jul 05, 2018
A Spectacular 4th from the Summit
Being atop Mt. Washington for the 4th of July with clear conditions was an incredible sight. As the sun set, we began to see the first fireworks light off. Small towns and houses began this small show. As the sky became darker, North Conway and Brenton Woods took over the show. Trying to see both sights was quite difficult actually. Running from the observation deck to the south east side of the mountain soon became a workout as I tried to get the best pictures of the light show. Watching the North Conway show soon allowed me to realize the larger scale of the event.
To the south and south east, Maine was lighting up. While the scale was not very impressive, the whole horizon was lighting up with different fireworks. It was truly an unbelievable sight with thousands of fireworks going off, looking like small puffs of flames, as seen above.
Now for the main event. We ran back to the observation deck to watch Brenton Woods. This ski resort with the Mt. Washington hotel gave us our closest show of fireworks. Less than 15 miles away, we were able to see the detail of the beautiful fireworks. We could even hear the loud booms because of the calm winds we had atop the summit. This show got better as it went on with a slight orange glow of the horizon from the sunset’s afterglow. The “oooos” and “ahhhhs” came out of us as the grand finale popped off. As it ended we continued to hear the loud booms because of the sound delay which was very cool to hear!
Wait, now for the main event. The Milky Way soon began to form over us and to the east. This incredible sight really capped off the night. The stars and the galaxy above us were truly the firework and celebration we need for the fourth of July. It made me realize how small we are on Earth. With all the fireworks looking like small campfires from the summit, the Milky Way ran supreme and mighty over the land and sky. Again realizing how lucky I am to work and live up here.
Zach Butler, Summit Intern
18:18 Mon Jul 02, 2018
A Crash Course in Cyclogenesis and Conveyor Belt Theory
Standing at the base of the mountain Wednesday morning, I was jumping with energy and excitement to get back on the summit this week. It doesn’t take much to get me excited in the first place, but this week was looking promising for storms. The storm that passed Thursday and Friday followed the classic mid-latitude cyclone lifecycle. This particular cyclone was already weakening as it hit New England so we only received a lot of rain and small cells scattered across New Hampshire. Later in the week we got some much nicer thunderstorms that were beautiful to watch as a meteorologist. Friday afternoon I was watching thunderstorms pop up all around me while I was doing little happy dances in my chair. After a weaker thunderstorm cleared the summit, I went outside to take a look at the large cell I had been watching on the radar just southwest of Mount Washington. Of course as I was admiring the storm to our west, I heard people talking about a rainbow to the east. It was gone by the time I turned around.
While all the storms were popping up Friday, I was asked a lot of questions about thunderstorms and ‘bad’ weather up here. So without further ado, here is my attempt at explaining some of this.
Most storms people think of are actually mid-latitude cyclones, and they generally produce lines of thunderstorm cells, or widespread rain. A mid-latitude cyclone is really just an area of low pressure that forms east of a dip in the jet stream in the Northern Hemisphere. We call these dips troughs because they generally are where large cold masses of air can be found. The jet stream weaves in between these pools of cold air and warm air. The air in the jet stream behaves a lot like cars on a highway, just before a tight turn the cars (air) pile up and create a traffic jam. Coming out of the turn, cars speed back up again and there’s a lot of space between cars. Thinking of air behaving like this, when the air piles up (converges) before a trough it creates high pressure before the trough, and low pressure after the trough where it spreads out (diverges).
The area of low pressure east of the trough starts out as a slight drop in pressure along a temperature gradient between the cold air and warm air. The warm and cold air behave like two separate masses of air, one of them is cold and dry, the other is warm and moist, and they don’t mix together. The low sitting in between the two air masses makes the wind turn slightly towards the low, and eventually the wind is making a full counter-clockwise circle around the low. This makes the warm and cold air masses start rotating around the low creating the warm and cold fronts. The type of the front is determined by which air mass is pushing the front forward. The cold front has the cold air mass blowing into the warm air mass and the warm front has the warm air mass blowing into the cold air mass. The warm air will rise up and over the cold air with both fronts because warm air has a lower density and cold air. At the surface this means the cold air gets wrapped completely around the low. When the cold air catches up to its back side the front turns into an occluded front because the cold air is blowing into itself. This is what eventually kills the cyclone because it needs that temperature gradient to sustain itself. I drew out the whole cyclone lifecycle below for reference.
The picture above shows the cyclone from the NOAA satellite GOES-16 on Thursday as it was entering New England. I’ve drawn the fronts on the image, but the cyclone was getting more disorganized at this time so it’s hard to picture the structure. Looking at the cyclone a day earlier shows a much more defined structure. The image below shows the cyclone from the same satellite Thursday through the moisture of the air; yellow indicates dry air and blue/white/green indicates moist air with green being the wettest.
The warm air blows north around the west side of the low and rises up and over the cold air at the warm front following the path shown by the red arrows. The cold air follows the black arrows and moves west on the north side of the low and wraps around to the western side of the low forcing the warm air up and over it along the cold front. The circulation of these air masses actually pulls in dry air from higher in the atmosphere just behind the cold front, contributing to the clearing and drying behind the cold front. The flow pattern of these air masses is drawn out in the diagram below.
The drying of the cold air and the fact that the cold air wraps around itself are the main processes that limit the strength and lifetime of the cyclone.
Sarah Thunberg, Summit Intern
16:35 Sun Jul 01, 2018
A Year's Worth of Snow In Review
At Mount Washington (and other weather sites) the conclusion of June marks the end of our yearly weather season. This is to encompass a complete winter, instead of splitting the winter up at the end of the calendar year. This means that yesterday was the end of the 2017-2018 snow season, and that starting today any snow (or sleet or hail) will count towards the 2018-19 winter season.
Rapidly changing weather is something you should expect at the summit of Mount Washington, and this past year was no exception. The year’s highest temperature of 67 happened in September. September 2017 ended up being 5 degrees above average and was even warmer than August, the first time this occurred since 1999. Winter 2018 was especially volatile for the summit. While over 80 inches of snow fell in December less than 30 inches fell in January. Daily temperature swings greater than 40 degrees occurred on 4 occasions, with two days where highs rose above freezing and lows dropped below 0. Additionally, February 2018 saw some record wintertime heat. Temperatures climbed to 48°F on the 21st, tying the all-time record high for meteorological winter (defined as the months of December, January, and February).
Winter made a comeback in March and ended up being colder and snowier than February. 68.6 inches of snow fell in March with a peak depth of 23”. Snowy conditions continued well into April with another 68.9” of snow falling – most of which fell in the second half of the month. While April ended up being the summit’s 7th snowiest April on record, things turned around quickly in May with no accumulating snowfall after the 0.1” on May 1st, making it the summit’s 3rd least snowy May on record. Conditions once again flipped in June; 0.8” of snow fell on June 5th, making it the first time since 1998 that more snow fell in June than in May. I suppose it’s not surprising that the weather pattern is once again changing as we head into July with record warmth in the upper 60s and lower 70s possible throughout the upcoming week!
Some quick 2017-18 stats:
Average annual temperature: 28.5 degrees (1.2 degrees above average)
Total Liquid Equivalent Precipitation: 88.56” (8.31 inches below average)
Total Snowfall: 345.1” (63.9” above average)
Average Wind speed: 36.2 mph (1.2 mph above average)
Quite an interesting combination if you think about it – while the 2017-18 season was drier and warmer than average, it was also snowier than average. Unfortunately as a summer intern, I missed out on 99.768% of the season’s snow (yes, that’s the actual percentage; I did the math). However, I did still get a chance to build a June snowman, and at least was able to see snow in July (today) thanks to the Jefferson snowfield that is just barely hanging on!
Snowman I built after our June snowfall.
Webcam image from this morning of the last remaining snow in Tuckerman’s Ravine
Simon Wachholz, Summit Intern