Tuesday, January 12, 2021

 

Mother Nature’s Snow Crystal Workshop


Snowflakes have to be one of the most interesting gifts of nature.  Whether you watch them fall from the sky from inside your home or get out to enjoy all of the activites that fresh snowfall has to offer, snow is one of those "other-wordly" parts of our daily lives for those who live in "snow country".  When you take the time to look closely, I mean really close to a snowflake, or more accurartely a snow crystal, what you will uncover is a whole new world of wonder.  I want to share some of the photographs I have taken of snow crystals over the past few years because they are just so beautiful.

Snowflakes have been around of course long before the dawn of man. I can imagine our early ancestors getting a close look at those flakes and wondering how in the world they were formed.   According to Kenneth Libbrecht's Snow Crystal Web Site  snowflakes first appeared in recorded history when individual snow crystals were identified and described as having that unique 6-sided symmetry.  Way back in 135 B.C., the Chinese scholar Han Yin wrote “Flowers of plants and trees are generally five-pointed, but those of snow, which are called ying, are always six-pointed.” Much later, in the 17th century, Renee Decartes gave detailed, naked-eye accounts of snow crystals but it was Johannes Kepler who provided the first scientific theories on snow crystal formation. 


Johannes Kepler gave this gift, The Six-Cornered Snowflake, to the Holy Roman Emperor Rudolf II for New Years' back in 1611.  

As you will see below, in the 1930s Uchikiro Nakaya, a brilliant researcher, developed a classification method for snow cyrstals based on the temperature and humidity profile in the atmosphere. By the way, my snow crystal "hero" is Wilson Bentley, who lived in Jericho Vermont in the 19th century and as an amateur scientist compilied one of the most thorough snow crystal photo catalogues out there. I will write about him and my experience working with his original photo plates and logbooks in a later blog entry, but I digress.  




Stellar dendrite snow crystal, photographed on a piece of black fleece with an Olympus TG-6 camera. This is a great camera for macro-photography, with "stacking" software built in.  Focus stacking is a digital image processing technique which combines multiple images taken at different focus distances to give a resulting image with a greater depth of field than any of the individual source images.

That stellar dendrite crystal above is one of my favorite specimens I photographed in the Tennessee Appalachians in February, 2020.  The term snow “crystal” is a more accurate way to describe individual snowflakes. The snow crystals may not be any larger than 2 to 3 millimeters in size.  In fact, those big fluffy snow flakes that you may be familiar with are often made up of hundreds of individual branched snow crystals that lock together to make flakes like this quarter-sized beheamoth that crashed onto my deck one winter day.
 

Take a close look at the snow crystals below and see how they are that specific geometric shape, 6-sided, or hexagonal.  That's not a coincidence.  All snow crystals are based on the hexagonal shape. This isn’t magic either, although I would say that the way in which nature makes these beautiful, natural sculptures is in some ways so much better than plain old magic. 


Hexagonal plate (left) and embryo (right) photographed under a microscope, backlit by a LED flashlights with color filters (pieces of plastic page protectors) attached. Notice the 6-sided theme in every single crystal. 

How Do They Form

It all starts with water, a really neat substance of nature.  As you know, water is a molecule made up of 2 hydrogen and 1 oxygen atoms (H2O).  In its solid state, these water molecules lock together into the 6-sided shape we all know and love as shown in this beautiful animation below.  In this blog I am not going to get into all of the physics and chemistry associated with the complete processes that produce a snow crystal, but I will touch on some of the basic concepts.  

(courtesy Kenneth Liebreccht, snowcrystals.com)

You may all be familiar with the traditional snow crystal, that 6-armed Christmas ornament or piece of jewelry like the image below.  In reality however there are many, many different types of snow crystals and it wasn't until I started photographing them that I really began to unlock the true miracle of this atmospheric factory that produces so many varieties. There are dendrites, plates, columns, capped-columns, prisms, needles, and other even more exotic designs.  


Traditional 6-sided spatial dendrite that most people are familiar with when you mention the term snowflake. Note the amazing hexagonal symmetry that is maintained in so many designs as you move out from the center, or nucleus, of the crystal.

Snow crystals begin with a simple hexagonal prism having two basal facets, or sides, and six prism facets.  Depending on a host of conditions withint the cloud, the crystal will either grow from the basil facet or the prism facet. If the ice nuclei grow outward in the hexagonal prism, you end up with a flat plate or dendrite crystal. Evetually, legs of  the crystal then grow outward from one of the six points in the hexagonal plate, which “stick out” into the moist air just a bit more than the sides. If the crystal grows upward from the prism face, you get a hexagonal column as the crystal grows in a vertical manner as shown below.



Ukichiro Nakaya was one of the first scientists to develop a system for snow crystal formation. As a result of his research work back in the 1930s, he developed the Nakaya Diagram, which described the relationships between the humidity and temperature in the clouds and the type of snow crystal that forms. Although the physics behind snow crystal formation is exceptionally complicated, the basic ideas are shown in his chart below.  What is so fascinating about the snow crystal is that its shape and design are a direct result of the atmospheric temperature and humidity profile it falls through on its way to earth. Nakaya so eloquently described the snow crystal as "A Letter From The Sky" because you could "read" the meteorological information "written" on the snow crystal.  


Observing These Sculptures of Nature


Living in Buffalo, NY I didn't have to look far for snow.  Even as a kid catching snow crystals on my tongue, they intrigued me.  I really discovered their intricate beauty with the help of my Black Labrador Retriever, Smoky.  I remember looking at snow crystals falling onto his fur one snowy day. His fur was fully insulated from his body warmth so the snow crystals did not melt.  That black fur served as the perfect background to look closely at the snow crystals and what I saw opened a whole new world for me. 


Snow crystals on a fleece jacket. This photo was taken with a plain old iPhone 5, in a future bolg I will show you how to get started photographing your own snow crystals.

Through my research work, I eventually obtained an old microscope, and with my little Canon G6 Point&Shoot camera and a couple dollars of plumbing parts to attach the camera to the eyepiece on the scope, I began to see what so many other scientists have discovered. With lots of experimentation I started finding success in documenting these amazing shapes.  In anticipation of a snow event, I couldn't contain my excitement when I started capturing the specimens and putting the glass slides under the microscope. More recently, with the improvement in macro-photography cameras like the Olympus TG-6, I was able to capture my photographs without the use of the microscope. In this section of my snow crystal blog, I will share some of those images below. Just click on each one to get an enlarged view and take the time to look at the details, its hard to believe they come naturally form the sky!

 
These crystal photographs are taken with the old microscope and Canon G-6 camera. They are post-processed to put them on nice backgrounds.  The details that you can see in each crystal are truly amazing!



Spatial dendrite photos taken directly with my Olympus TG-6 camera. With this camera, you can get a much better look at the crystals in 3-D.  The crystal on the left is attached to the hairs of an artist's paint brush. The threads in the background of the other images are the black fleece that I use to collect my specimens. 


These snow crystals all have a few things in common. Each one of them is covered with all of those little frozen droplets. In one of my next blog entries I talk about how this process works. Stay tuned... 

I plan to author a few more blog entries on snow crystals soon. They will include all of my instructions on how to get started photographing snow crystals, a nod to my snow crystal hero, Wilson Bentley, whom I consider the "Father of Snow Crystal Photography", and finally and extensive gallery of some of the hundreds of snow crystals I have photographed, and there are a few that are really "other-worldly.  Stay tuned for that and much more!!

 


Wednesday, December 30, 2020

 

Temperature Sinks - Antero Reservoir, Colorado Hits -50°

 

On the evening of December 29- 30, 2020, Antero Reservoir, deep in the Colorado Rockies, recorded a low temperature of -50°F, the lowest temperature in the U.S. so far this winter.  In fact, it was the coldest temperature in the U.S. since February of 2019!  How in the world can the temperature get so cold?  In this blog entry I hope to share the conditions that led up to this frigid night, and also highlight some other locations across he U.S. and worldwide where specific topography and weather conditions can produce wild temperature extremes like this one.  

I love to look around the US each day and see where the coldest weather occurred.  I regularly check the  National Weather Service link for the National Daily High and Low Temperaturereported across the US.  What I have found so interesting is that the same locations tend to show up from time to time and the minimum temperatures amaze me!  By the way, they are not always International Falls MN, the reputed “icebox” of the nation.  So, here’s a question for you.  What do Antero Reservoir, Canaan Valley WV, “The Barrens” outside State College PA and Peter Sinks, UT have in common?  Well, they all are what are referred to as “temperature sinks” and they get darn cold compared to locations in close proximity. 


What Is A Temperature Sink

A temperature sink, as the name implies, is a location in a natural sink, sinkhole or bowl, typically found in the mountains, surrounded by higher ridges.  Without an outlet down a mountain valley, cold air does not drain from these “sinks” and they can continue to get colder and colder as the night progresses.

Antero Reservoir is a classic temperature sink.  Its topography, along with some fascinating properties of cold air, and select meteorological conditions, led up to this frigid temperature.  As you may know, cold air is more dense than warm air.  As the sun begins to set on a clear, calm, dry night, the ground begins to radiate its heat into the atmosphere and the temperature right near the surface cools. As the air temperature drops, the cold, dense air acts like molasses, sliding down mountain sides and pooling in the low-lying areas between slopes as shown below. You can even feel this effect locally if you live in an area where there are dips in a road or depression along a trail you might be walking along.  As the sun sets, that colder air will pool in those areas and as you walk down the slope you will feel like you may have even walked into a fridge or freezer. 

Simple schematic showing what happens around sunset on a clear, calm night.  As the ground begins to radiate heat into the atmosphere, the air temperature cools and the colder, more dense air slides down the mountain slopes into the valley below.

From a meteorological standpoint, the downslope movement of air that occurs in an otherwise calm evening with no breeze is known as a katabatic wind, or drainage wind and it leads to cold air pooling within mountain valleys.  As the cold air pools in the valleys, the local atmosphere develops a temperature inversion, where the coldest temperatures are at the surface and there are warmer temperatures aloft.


 Antero Reservoir and Perfect Frigid Weather Conditions


Cross-section of Antero Reservoir in the Colorado Rockies shows the bowl that it is located in with mountain ridges surrounding it in all directions. 


That’s exactly what happened at Antero Reservoir on the night of December 29th-30th, 2020.  The entire region was under a fair-weather High Pressure system accompanied by clear skies and calm winds.  In addition, this region had a deep, fresh snowpack in place. On a calm, clear night, fresh snow-covered surfaces cool much more quickly than a bare surface at the same temperature. Snow “radiates” heat very efficiently, and that increases the rate of heat loss at the surface. Snow is also a great insulator and that prevents heat from rising through the snowpack, allowing the surface to cool quickly. In contrast, bare soil conducts much more heat upward from below, which helps slow down cooling at the surface.


High Pressure was strecthed across the Colorado Rockies and wind conditions were calm in the area around Antero Reservoir.



This satellite animation taken during the following daytime on December 30, 2020 shows the fresh snowcover across Colorado and the clear skies.  Along with the calm winds, the atmopshere set up for a perfect night to chill down to extremes. 


As a result of all of these factors coming together, cold air then pooled down at the base of the bowl in which Antero Reservoir is located and the temperature plummeted to the reading of -50°F.


Other Locations That Are Temperature Sinks

As I noted above, this is not the only location in the U.S. where there are weather instruments available to monitor these extremes.  One of the most famous is Peter Sinks, Utah. According to the Utah Climate Center “On Feb. 1, 1985, the temperature at Peter Sinks location plummeted to -69.3°F, the second coldest ever recorded in the lower 48 states. The lowest was -69.7°F at Roger's Pass, Montana in January 1954.” Peter Sinks has been studied a lot by the meteorological community. In fact, there is weather equipment set up on the rim of this sink as well as the base of the bowl, only about a 300 ft. difference in elevation but wow can the temperature differences be extreme. This is the essence of micro-meteorology. 

Comparison of daily minimum temperature at the base and rim of Peter Sinks, Utah on several consecutive nights from December 25th through 30th, 2020.  The rim of this 1km. wide sinkhole in the Wasatch Mts of northeastern Utah is less than 300 ft. above the base, but temperature differences at night can be 50°F or more.

The conditions that were so favorable for Antero Reservoir on the evening of December 29-30 were similar the night before in Utah. Check out the temperature profile I plotted from December 25 through December 30.  Notice on the might of December 29, the temperature at the base of the bowl, or sink, dropped to -38°F, while less than 300 ft. higher on the rim of this 1km. wide bowl the temperature was 50 °F higher at 12°F!  No, this did not take place on the planet Mars, rather a remote site in the Wasatch Mountains of northeast Utah.

What’s fascinating about some of these locations where temperatures get so cold at night is that they share other characteristics of the micro-climate including the soil type as well as the vegetation or lack thereof.  Why are those factors important?  Well, to amswer that question, let's visit a place called “The Barrens”, located in Central Pennsylvania, about 4 miles west of the Penn State campus.  According to The Pennsylvania State Climatologist this location has similar daytime maximum temperatures each day to the Penn State Campus, but at night, under conditions described above there can be as much as a 30°F difference in the minimum temperature at the 2 locations!  The table below shows the distinct differences between daytime high temperature and overnight lows at The Barrens vs. its neighbor at State College.  Note, that during this study State College only experienced 1 night with a temperature below 0°F while The Barrens saw temperatures below 0°F 31 times!

 

A Frequency Distribution of Temperatures at the Barrens and State College (1200Z to 1200Z from December 1977 to November 1978).  (courtesy: The Pennsylvania State Climatologist)

Once again, topography plays a major role in the micro-climate of The Barrens, but there are also other characteristics of the site, shared by the other locations around the U.S. mentioned above, that allow it to cool so rapidly at night.  The Barrens has a surface of sandy soil which allows water to be absorbed deep into the ground, keeping the surface layer dry.  That results in a rapid loss of heat from the ground after the sun drops below the ridges. The other feature of the Barrens that contributes to rapid temperature loss is very little vegetation other than some scrub trees.  In fact, in many of these “sinks” or depressions, there may even be a “vegetation inversion”, with only s few scrub trees and grasses where the temperatures undergo drastic daily changes, while up on the slopes of the mountain there are more mature trees and more lush vegetation. 

Next, let’s stay in the East, and visit a beautiful location in The Appalachian Mountains at Canaan Valley, WV.   It’s another great place to study micro-meteorology, because at this site, maintained by Virginia Tech, there are two weather sensors that measure temperature, one at the base and one at the  ridge of the bowl.  Below is a cross-section I derived off Google Earth to show Canaan Valley.  As you can see, the location sits in a depression or bowl surrounded by higher ridges.  The elevation difference between the weather sensor at Canaan Valley (elevation 3150 ft.) and the Cabin 2 site on the right-hand ridge (elevation 4035ft.) is just under 1,000 ft.  and a distance of a little over a mile.   The sensor itself is located on a barren piece of ground, with a sandy soil and not much vegetation.

 

Cross-section of Canaan Valley WV, showing the location of the sensor in relation to the elevation changes from one side of the bowl to the other.

Back on Christmas Day of 2019, under clear skies and calm winds, Canaan Valley dropped to 10°F while the ridge sensor was reporting a temperature of 43°F.  That equates to a 33°F difference in temperature over a distance of a little over a mile! In fact, under a fair-weather High Pressure system, with a very dry atmosphere, clear skies and calm winds, this area saw 3 straight days of extreme temperature differences.

Temperature trace for Canaan Valley WV and Cabin Mtn2 on 3 consecutive days from December 24th through December 26, 2019 showing the extreme difference in readings at night, while daytime highs showed very little difference.


There are many, many other locations across the U.S. and of course worldwide, where the phenomenon of “cold air sinks” occurs.  In fact, in Central Europe, one of the most well-known is Gruenloch Sinkhole in Austria, where conditions that created the sinkhole, including a collapsed limestone rock base, are perfect for the development of extremely cold temperatures.  I believe the site still holds the record for the coldest minimum temperature in Central Europe, at -62.7°F (-52.6°C).   There has been much research in other parts of the world including Scandinavia and Japan on these features as well. 


Summary

In closing, there are several factors that combine to produce such cold temperatures. In addition to clear skies and calm winds they include:

-        Topography - A valley setting with slopes on all sides that form a bowl, allowing for cold air drainage and with no valleys in the bowl, the cold air becomes trapped to continue to chill throughout the night.

-        Soil type – Sandy soils or limestone lose heat to the atmosphere more quickly than other soils, namely because they allow water to permeate through them and dry soils lose heat more quickly.  If there isn’t much ground cover in the form of trees or other vegetation, that adds to heat loss more quickly.

-        Snow cover – These mountain valleys will stay colder, and hold snow longer in winter, and snow cover is a great emitter of long wave radiation, or heat loss to the atmosphere.

-        The development of a temperature inversion over the valley will prevent turbulent mixing and it effectively “cuts off” the bubble of cold air from the atmosphere above it, allowing these areas to continue to cool through the night.

As someone who hikes quite often, I remind myself how important it is to remember that when you decide to make camp for the night on a clear, calm evening, especially during the colder times of the year, a decision to pitch your tent in a little depression or valley could not only result in a really cold night, it could be life-threatening.  Setting up a tent or hammock in a valley bottom under cold, clear conditions, will expose you to the coldest temperatures in the area as that cold, dense air slides down the slopes and envelopes your campsite. In these cases, if at all possible, it’s often better to set your camp up a little way up the mountainside.

Keep an eye on the “National Daily High and Low Temperature” each day if you get a chance.  Check out the locations and see if they share some of the factors that I have discussed in this article. Don’t get caught with that “sinking” feeling.    









Wednesday, December 23, 2020

 

Blizzards - Notorious Winter Storms
 


With the impending blizzard that is part of a complicated storm system crossing the U.S. this Christmas Week, I thought it would be a good time to talk a little bit more about them. The image above was valid at 9:00AM Wednesday, December 23, 2020 and shows the states outlined in orange that were under Blizzard Warnings.

The animation below is from the U.S. GFS model showing the forecast track of the storm that is responsible for the blizzard conditions across the Northern Tier of the U.S.  


What Are They

BLIZZARD, that term evokes thoughts of whiteouts, extreme cold, getting stranded and lost outside. For anyone who has ever experienced one, it can be scary and certainly dangerous.  Most of you have an idea of what a blizzard is, but there is an actual definition for what it takes for conditions to be considered a blizzard. In the Glossary of Meteorology, a bible of sorts for weather terms, a blizzard is defined as:

-        sustained wind or frequent gusts of 16 m per second (30 kt or 35 mi per hour) or greater,
-        accompanied by falling and/or blowing snow,
-        frequently reducing visibility to less than 400 m (0.25 mi) for 3 hours or longer.

In a nutshell, they produce strong winds, very reduced visibility and lasts for at least 3 hours.  The timeframe is an important factor in the definition of a blizzard because often in snowstorms you can get a short period of those conditions but if they last long enough, they can strand people, livestock and anything else outside to make conditions life-threatening. Note, it doesn’t have to be snowing either.  The Northern Plains are notorious for “ground blizzards”, storms that whip up loose snow cover into the air to create those same conditions. I have been in ground blizzards before where at times you could look skyward and see clear conditions above the shallow storm.


Where Do They Occur

There are favored locations across the U.S. for blizzards. In fact, I have often referred to an area I call “Blizzard Alley”, a roughly 5 to 8 state region, from the Northern Plains and parts of the Central Plains and Upper Midwest.  The two most notorious states are North and South Dakota. Take a look again at the map below and compare that to the region where Blizzard Warnings are in effect for this week’s storm. That is why I consider this storm to be a textbook blizzard for location.


The total number of blizzards recorded by county during 41 winters 1959-60 to 1999-2000.



Blizzard Alley has specific features that are conducive to blizzards. The area is pretty flat, allowing for strong winds to blow unimpeded through the Alley. It is wide open to Canada, where some of the coldest air in the continent regularly spills down to the States.  The cold air assures that the snow, falling or on the ground is fluffy enough to be blown around to reduce visibility.  Finally, it is in a perfect location for two particular types of weather systems know to produce blizzards, Colorado Lows and Clippers.

Colorado Lows are storms that typically develop off the Rocky Mountains in the vicinity of Colorado. They intensify rapidly and move northeast toward the Great Lakes. They often will pull Gulf of Mexico moisture up with them.  To the north and west of their track they produce very strong winds and very heavy snowfall. Clippers are fast moving storms that typically form off the Canadian Rockies in places like the province of Alberta, and head east along the northern latitudes of the U.S.  These storms normally move faster than Colorado Lows, so they are of shorter duration. They also do not produce as much snow, they are considered moisture starved.  However, because they move so fast, they can catch people unprepared.  Below is a breakdown of the occurrence by state of these two types of storms in the vicinity of Blizzard Alley.  The storm this week is a hybrid of a Clipper System. It began off the Rockies in British Columbia and moved very rapidly eastward through the Northern Plains. After that, it’s Clipper characteristics change as it gets to the Great Lakes Region and morphs into a major winter system for the East.

 


Although blizzards are most common across Blizzard Alley, they occur across a large portion of the U.S. in any given winter. A study of the number of blizzards that have occurred in a 41-year timeframe from 1951-200 is shown below. As you can see, they have hit most of CONUS, with the exception of 5 states, mainly in the Southeast.


The total number of blizzards recorded by county during 41 winters 1959-60 to 1999-2000.


How Bad Can They Get


The dangers of being caught in a blizzard unprepared cannot be overstated.  With visibilities reduced to just a few yards at times, “whiteouts” on open roads can bring traffic to a standstill, you literally lose the road in front of your eyes. Often, the only way to proceed ahead is to watch the brake lights on the vehicle in front of you. Guess what, if the guy in front of you goes off the road, you will likely follow him. Once you are stuck, it is often difficult to get help because even emergency vehicles won’t risk going out in a storm like this to get stuck as well.  Below is a video of someone driving through a blizzard. Notice that the winds will also drift snow across roadways making them even more difficult to negotiate.  It’s gets pretty scary.



Historically there have been some terrible tragedies associated with these winter storms. Back in the 1888, long before there were accurate daily weather forecasts, the “Schoolhouse Blizzard”,  also known as “The Children’s Blizzard” hit very quickly after a warm and sunny day in mid-January across Blizzard Alley.  Many were caught outside completely unprepared for the extreme, and very rapid, change in the weather. As a result, over 200 people died in this storm, many of them children on the way to and from their schoolhouses, which were often several miles from their farms. 

More recently a massive blizzard back in October 2013 resulted in catastrophic consequences for ranchers and livestock.  The storm impacted thousands of ranches in western South Dakota.  Over 5 ft. of snow fell, winds gusted over 70 mph. As a result, livestock herds caught out in the open ranch land, were scattered for miles and resulted in the deaths of thousands of cattle due to exhaustion and hypothermia.




How To Prepare

The life-treatening conditions that accompany blizzards are why it is so important to have you and your car prepared for these conditions. Make certain you have a fully charged battery, always keep you gas tank filled, I like to say don’t let it get down below ½ a tank at any time.  Carry extra winter clothes including a hat, boots, gloves, a blanket, a cell phone charging block, and extra high energy food like protein bars. I also like to carry some extra water, although you need to make sure bottles do not crack if they freeze in your vehicle.

Finally, listen to the local forecasts for your area. It’s important to adjust any travel plans well ahead of time. The good thing about surviving a blizzard, if you prepare and hunker down until it has passed, you can escape most of its impacts. Understand that power outages often accompany them, so make sure your home is prepared as well, with flashlights, charged cell phones, and check with other family members to make sure you know where they will be.  Last but not least, in the event of a power outage, I always caution anyone who has a back-up generator to know the proper safety for using them. They MUST be put outdoors with adequate ventilation, away from a building, not under porches, nor in open garages, so that the deadly and odorless exhaust gas, carbon monoxide, does not overtake unsuspecting people.  There are many deaths every year from improper use of these systems.  

Being prepared and knowing the forecast will go a long way in living with these notorious winter storms.  In fact, once you and your family are safe at home, getting through the worst winter weather becomes much more manageable. Stay safe.  

 

 

 

 

 



Monday, December 21, 2020

Japan's Epic Snows - December 14-17, 2020

  

1,000 Stranded Vehicles in Japan SNowstorm

Above, Reuters reported 1,000 vehicles stuck on snowbound highways in Japan after a major winter storm dumped as much as 85 inches of snow in some locations.

While the northeastern U.S. was getting pummeled by a major Nor’easter last week, halfway around the world, at about the same latitude, residents in parts of Japan were getting their own epic snowstorm.  Over the course of 3 days Fujiwara set an all-time snowfall record with 219 cm. or 86 inches of snow.  BBC News wrote that 1,000 drivers were stranded in their vehicles during and immediately after the storm.  

For some, this news may come as a surprise, but snow-savvy weather geeks as well as skiers know Japan as one of the snowiest places on earth.  The reason as the old business adage goes is “location, location, location”.  Japan is made up of many islands, its two largest are Honshu and Hokkaido.  The nation is situated in the western Pacific Ocean, separated from the Asian continent by 300-500 miles across the Sea of Japan.  There are several mountain ranges that stretch down the spine of these main  islands, with several peaks exceeding 10,000 ft.


So, what does this location have to do with heavy snow? Below is an image from the NASA polar orbiter satellite showing hundreds of cloud streamers forming on northwest winds, a little downwind of the Asian continent, moving across the Sea of Japan and impacting the western Coast and well inland across Japan.  As is often the case with weather extremes, several ingredients usually come together in the right place at the right time to maximize their effects.  In Japan’s case those ingredients are very cold air over Siberia, transiting the relatively warm Sea of Japan where they pick up heat and moisture, then those winds hit the mountains of Japan perpendicularly, maximizing lift to “squeeze” out moisture in the form of snow. This type of snow event is often referred to as “ocean-effect” or “sea-effect” snow. 


To illustarte just how much the arctic air is wamred as it crosses the Sea of Japan,  I have added the prevailing wind direction along with the temperature upwind of the Sea of Japan at Vladivostok, and the temperature downwind at Wajima for December 16th.  Look at how much the air has heated as it crossed the warm waters of the Sea of Japan, 19.8 degrees Celsius or 35.8 degrees Fahrenheit!


In fact, not only does the surface temperature warm, but the entire column of air warms and moistens considerably through the mid-levels of the atmosphere, where clouds and snow develop, as it crosses the sea. Below are the atmospheric soundings taken at both Vladivostok and Wajima on December 16th at 00z.  The soundings show two lines, temperature on the right and dewpoint on the left. The x-axis denotes temperature and the y-axis shows altitude in millibars (mb.) of pressure.  For those not familiar with millibars, the 700mb level is approximately 10,000 ft. in altitude and 500m is about 18,000 ft.





Notice at Vladivostok the air is very cold, quite dry and there is a very strong temperature inversion that “caps” the shallow layer of arctic air at a low 1382 m.  (~4500 ft.).  You can't make clouds that produce snow with such a dry and shallow layer of cold air.  Hence the clear skies on the satellite image along the Russian Coast. However, by the time the air has crossed the 400-500 mile distance over the Sea of Japan, at Wajima, the column of air has undergone extensive modification through the mid-levels of the atmosphere as there is a flux, or flow, of heat and moisture that rises from those warm waters into the overlying column of cold air.  As a result, there is a significant decrease in temperature with height, referred to as the lapse rate, and that allows air parcels to stay buoyant and rise rapidly until they get to the temperature inversion.  In fact, the “capping” temperature inversion at Wajima had risen to nearly 4,500 m. (~15,000 ft) and the amount of precipitable water in the column of air has risen from 1.8 mm. at Vladivostok to a whopping 8.4 mm. at Wajima (Precipitable water is the depth of water in a column of the atmosphere, if all the water in that column were precipitated as rain).  Put this all together and by the time those air parcels get across the Sea of Japan, they have produced clouds that grow up through 15,000 ft. and higher, dumping very heavy snowfall. The little cumulonimbus cloud on the Wajima sounding reflects that deep layer of cold, moist air with a steep lape rate, perfect for growing snow clouds. 


The snowfall across the western shore and into the mountains of Japan continued unabated for a 4-day stretch as the large-scale weather pattern persisted.  Below is a 2-hour radar animation from December 16, 2020 along the northern portion of the island of Honshu in the Tohoku Region.  Notice the parallel bands of snow, aligned with, or longitudinally along, west to northwest winds.  As long as the winds stay out of the same direction, the bands of snow will not move, and one area will get huge amounts of snowfall.  I liken this to stick one end of a firehose into the water and pointing the other end downwind over a particular spot.  As long as I do not move the nozzle (change the wind direction) that area I am pointing at gets "pasted" with snow. 


If this sounds familiar to residents of the Great Lakes Region who experience “lake-effect” snow, it should because the concept is the same. However, everything occurs on a much larger scale in Japan. To begin with, the Sea of Japan covers about 12 times the surface area of the Great Lakes.  The average water temperature of the Great Lakes chills to near the freezing point with significant ice accumulation on most of the lakes during mid-winter.  In contrast, the water temperature of the massive Sea of Japan in February is much warmer, averaging some 8 to 12 degrees Celsius (46 to 54 degrees Fahrenheit) even in February.  That equates toi a tremendous amount of energy to fuel these snowstorms. Finally, the various mountain ranges that stretch along the spine of Honshu and Hokkaido exceed 3,000 m. in some locations.  Downwind of the Great Lakes, the Allegany Plateau and Tug Hill Plateau rise less than 1,000 m. MSL.  The Japanese mountain ranges add significant lift to the already buoyant air, maximizing the production of snowfall.

As a result of those characteristics, some locations in Japan, even at low elevations closer to the west coast, see huge annual snowfall on average. Saporro of Winter Olympics Fame, averages about 250 inches of snow each season. Higher up in elevation, some of the mountain locations exceed 500 inches of snow each year (Japan Meteorological Agency, 1981-2010 Normals).  That amount of snow can lead to some amazing snow depths and one of the most famous snowcover images I have ever seen comes from one of these areas a few years back. Visitors from around the world flock to the Tateyama Kurobe Alpine Route (Source: Uryah, Wikipedia Commons, CC BY-SA 3.0) to see the snow corridor that builds each winter season as a result of a few ingredients coming together at the right time and right place in Japan. 


This phenomenon of Mother Nature is just another amazing example of how interesting the atmosphere can be. I often refer to the term “other-worldly” when I see events like this occur. That is why I am so happy to share my curiosity about the weather with you. Enjoy !

BTW, the latest long-range forecast for Eastern Asia the last week in December shows a massive push of Arctic air coming across Eastern Asia/Siberia and right over those warm waters of the Sea of Japan. Methinks there will be even more snow to add to those already amazing totals.  Here is an animation of the 850 mb. level (about 4500 ft. altitude) temperature departures (blue is colder) from Christmas Eve through New Years Eve.  



Sunday, December 20, 2020

The Weather and Nature Blog
Fun Facts, Interesting Photos, Great Stories

I am dedicating this blog to share some of the geeky things I have observed and learned about all kinds of weather. I do NOT profess to be an expert on any of these topics. However, with a 40-year career in meteorology, much of it working at the National Weather Service office in Buffalo, NY I do enjoy winter.  In addition, working for The Weather Channel as the National Winter Weather Expert for several years, I became very familiar with covering some of the wildest winter weather across the United States. I want to share some of the amazing information about the workings of our atmosphere and answer questions you might have on "things you see in the sky".  I will probably get a little too geeky at times sharing my enthusiasm about “all things weather” from around the world, so be pateint with me.  I will also touch on other things I see in my daily hikes and saunters through the Appalachian Mountains here in far Eastern Tennessee. 

Please sign in on the "Follow By Email" tab so you can get notices for my latest blogs.  You will receive an email and you need to click on the link to activate it so when I post another article, you will get notified.  This is also my first attempt at creating a blog, so there will likely be errors in navigating this site. Send me comments and suggestions to make it better.  Stay tuned for the next blog, I will give you a hint, it has to do with A LOT of snow !!

Looking down at the "undercast" from high atop Round Bald on Roan Mountain. elevation 5826 ft. We are looking down at the top of the cloud mass, rather than the normal way you might see it, from below the clouds. We will discuss how and why this cloud pattern develops in future blogs. 

As a meteorologist I have always loved to watch the sky and try to figure out what is going on up there in the clouds.  I also have always had an unquenchable curiosity about nature in general, whether its bugs and insects, flowers and trees, rivers and streams or mountains and lakes. For the past decade or so I have been photographing everything I see and I plan to share a lot of those photos with you.


Rime Ice atop Roan Mountain, what is it and how does it form?  We will check that out too.

My first article will come right after this introductory blog. I hope that you will spend some time reading through my posts. Please share them with as many people as you like. I look forward to your comments as well as any suggestions you have to make the blog better and I entertain any topics you would like to hear more about.

Ahhh snow crystals, my favorite winter hobby is to photograph them. We will learn how to photograph snow crystals and why they are 6-sided.