Extreme Snowfall Events - Climatology

[Adam Adkins]

The climatology of severe weather events, including large hail and tornadoes, is somewhat easily researched and diagnosed. Just about the most prone area for violent tornadoes in the CONUS is area near Moore, Oklahoma, and we know that. There are many reasons that could be, but to summarize them, the surface features of the surrounding area such as land-use, ground cover, topography, elevation, proximity to large features in the CONUS like the Gulf, the Rockies, and desert southwest, to even proximities to more small-scale, local features like valleys and rivers, forests, as well as what typical features are upstream vs downstream in the greater context of the storm itself. Even the large-scale system tends to behave in similar ways due to the landscape it is impacting. For all those general reasons added together, Moore (and the surrounding area) has a higher probability of receiving a violent tornado, climatology speaking, than anywhere else in the US.

Similarly, these millions of factors surround other weather events and play a role in causing certain areas to be more prone to extremes. Of course, extreme events can happen elsewhere, but climatologically speaking there should be somewhere that is most likely to get them. I'm interested in snowfall.

It's difficult to find records of exactly where the heaviest snow falls in the shortest amount of time most frequently. Summertime extreme events are much more sought-out and reported; everyone is interested in the biggest tornado or the largest hailstone. But what about the heaviest snowfalls? For most snowfall records, we are relying on the location of the station or reporter to begin with, rather than receiving information from those who have sought-out the worst of the storm.

With the data we have though, we can make assumptions, like the obvious ones (certain mountainous areas most likely receive extreme blizzards most frequently), but that's a given. I'm curious to know where, an inhabited place in the CONUS, is most likely to get extreme snowfall/blizzard events, and where has the "makings" necessary to provide the most extreme snowfall accumulations of anywhere, if all things came together perfectly. Lake-effect areas certainly are prone to big snows, but there are other areas that are most likely just as prone. And as to the second part of my question, I'm not so sure lake-effect areas have the "makings" for the absolute largest snowfall events in a say, 100-year event. I think those areas are going to be terrain-influenced.

So I'm doing research on this personally, but I would love having thoughts and opinions from the forum. Maybe some of you have some information on this that would be useful. Apart from uninhabited America (many mountain areas), or mountain areas that are accessible and traveled but not really inhabited, where do people live in this country that can produce the most extreme snowfall/blizzard events, and is most likely to get big winter storms in general? The Moore, OK area gets tornadoes. Where is the winter powder-keg?

 

[Alex Elmore]

The climatology of severe weather events, including large hail and tornadoes, is somewhat easily researched and diagnosed. Just about the most prone area for violent tornadoes in the CONUS is area near Moore, Oklahoma, and we know that. There are many reasons that could be, but to summarize them, the surface features of the surrounding area such as land-use, ground cover, topography, elevation, proximity to large features in the CONUS like the Gulf, the Rockies, and desert southwest, to even proximities to more small-scale, local features like valleys and rivers, forests, as well as what typical features are upstream vs downstream in the greater context of the storm itself. Even the large-scale system tends to behave in similar ways due to the landscape it is impacting. For all those general reasons added together, Moore (and the surrounding area) has a higher probability of receiving a violent tornado, climatology speaking, than anywhere else in the US.

1) Moore has had some very bad luck with violent tornadoes tracking over the same areas in the last few decades, but so have other Great Plains and Midwest cities and towns. Just off the top of my head, the St. Louis and Chicago areas have had their fair share of violent tornadoes throughout history; though, violent tornado climatology favors the Southeast as per the SPC WCM page (scroll down to the "30-year Severe Weather Climatology"): Storm Prediction Center WCM Page

2) Researchers are just now beginning to be able to look into how land use and small-scale topography impacts weather, including tornadoes, due to the better availability of spatially and temporally high-res satellite imagery. I'm not aware of any studies that have any firm conclusions on how these impact tornadoes, but if there are any, I'd love to know about them. Larger topographical characteristics, like the Gulf, Rockies, and desert Southwest impact larger scale features, like dry line development and placement or the ability of the Southeast to produce violent tornadoes just as the Great Lakes impact lake effect snow. Mountainous areas will have similar impacts, but I'm not aware of anything of spatial scale features on the order of land usage that would cause regularly cause heavy snow.

It's difficult to find records of exactly where the heaviest snow falls in the shortest amount of time most frequently. Summertime extreme events are much more sought-out and reported; everyone is interested in the biggest tornado or the largest hailstone. But what about the heaviest snowfalls? For most snowfall records, we are relying on the location of the station or reporter to begin with, rather than receiving information from those who have sought-out the worst of the storm.

With the data we have though, we can make assumptions, like the obvious ones (certain mountainous areas most likely receive extreme blizzards most frequently), but that's a given. I'm curious to know where, an inhabited place in the CONUS, is most likely to get extreme snowfall/blizzard events, and where has the "makings" necessary to provide the most extreme snowfall accumulations of anywhere, if all things came together perfectly. Lake-effect areas certainly are prone to big snows, but there are other areas that are most likely just as prone. And as to the second part of my question, I'm not so sure lake-effect areas have the "makings" for the absolute largest snowfall events in a say, 100-year event. I think those areas are going to be terrain-influenced.

1) Any weather phenomenon can be impacted by sparse population or no one to record it. Severe weather regularly occurs in areas where there is nothing it hit (e.g., lack of visible wind or tornado damage) or no one to see it (e.g. hail stones). Heavy snowfall would be even harder, as if there is a lot of snow on the ground, traveling to areas that may have the highest totals would be difficult and dangerous.

2) I apologize if this comes off as picky, but lake-effect snow is terrain induced, just not in the same way that mountain snow is.

3) If you're willing to comb through research articles and journals, you could try various searches in google scholar for what you're looking for. An easier way to find information for event-specific or area-specific snow fall rates would be the various NWS office pages. Offices are usually pretty good at having their local climatology and write ups for significant events on their pages.

 

[MClarkson]

At least for the US, If the definition is snowiest location that is lived in with plowed road access, year-round, I think its gotta be timberline lodge on Mt Hood. ~550 inches of pretty high-density snow a year. This tops the small settlements at stevens pass(450 inches) and Snoqualmie/Donner(400 inches each). It dwarfs the ~500 inches or so of very low density snow recorded at many interior ski towns further from water.

Of course these are all tiny settlements... but they are inhabited year round.