Geography: I make weather observations and measure snowfall from storms in my back yard in the town of Waterbury in the state of Vermont. The map above on the left gives the approximate location of our house. Some of the surrounding states in the Northeastern U.S. are labeled for reference, with the thicker green border lines indicating the state boundaries. Also shown on the map are counties, indicated by the thinner green lines. Our house is located very close to the border between Vermont's Chittenden and Washington counties, and as with many other borders in the state, there is at least a partially geographical basis for the county line. The division between the counties of Chittenden and Washington is very much in line with the spine of Vermont's Green Mountains, which run generally through the center of the state from north to south. We are located at an elevation of 495 feet along and a bit up from the Winooski River, which runs through the area at an elevation of roughly 380 feet, and eventually flows down to an elevation of 95 feet where it dumps into Lake Champlain in the Burlington area about 20 miles to our west. The Winooski Valley is a major route of east-west travel through the area, as the river has cut a deep swath through the Green Mountains. Our location is sandwiched between some of the highest peaks in the range, with Mount Mansfield, the highest in the Green Mountains at 4,395 feet about 10 miles to our north, and Camel's Hump, the third highest peak at 4,083 feet about 4 miles to our south. Another important local peak is Bolton Mountain, which is about 6 miles to the north of us and 20th in height among the Green Mountains, rising to 3,680 feet. Bolton Mountain sits at the head of a long box-canyon type valley (Bolton Valley) that also contains the local ski area of the same name. The Green Mountains form an impressive wall with roughly 4,000 feet of vertical relief above the lower valleys in the area, a setup that is well known throughout the region for producing notable orographic enhancement of snowfall. Indeed, the Green Mountains, especially those north of the Winooski Valley, are famous for having some of the highest annual snowfall totals in eastern North America and average more than 300 inches of snowfall each year. Our location, although relatively low in elevation, is in line with the Green Mountain spine and appears to get in on some of the orographic precipitation enhancement caused by the mountains as storms are squeezed through the Winooski Valley. The image below is taken above the dam on the Winooski down below our house, and gives an idea of some of the local topography as you look up from the bottom of the valley. Since there are no major mountains directly to our west, we also appear to avoid most precipitation shadowing. Although at our elevation we do not get as much snow as is seen higher in the mountains, we generally get much more snow than locations to our west in the Champlain Valley that are at similar elevations. For example, the National Weather Service office in Burlington is located at the Burlington International Airport at an elevation of roughly 330 feet, and the annual snowfall average is 81.0 inches. The snowfall at our location in Waterbury appears to run at around 150-200% of what Burlington receives, with our highest season total being 203.2 inches recorded during the winter of 2007-2008.

Snowfall Collection: I have an elevated snowboard (pictured below) in the back yard, which is just a white board made of plastic building material affixed to a pole. The snowboard platform is about 34 inches above ground level, a somewhat arbitary height that came about simply because that was the point at which my pole had sunk in the ground enough to be stable, and it seemed like a convenient level for reading snowfall measurements with a ruler. Although I didn't know it when I set it up, the board height of approximately three feet seems to be appropriate for our location. The deepest snowpack I've recorded at the house since I started taking measurements in the winter of 2006-2007 is 37 inches, which was reached after the February 2007 St. Valentine's Day Snowstorm and again after the March 2007 St. Patrick's Day snowstorm. Since the point at which we moved to this location in October of 2006, that Valentine's Day Storm still stands as our greatest individual snowfall event, delivering 29.2 inches of snow. So, the snowpack in the yard has occassionally reached a level slightly above the board, but it hasn't been so far above it that the board has ever been buried. With regard to snowpack depth and board height, there are a couple of things to note about this type of stationary snowboard setup. Throughout a long winter of snowfall, the snow that has been collected on the board and pushed onto the ground will actually create quite a mound, so one may find themselves having to push that pile of snow back or knock it down so that it doesn't impinge on the board. The other thing to be aware of is that constantly waking to and from the board and working around it all winter, will heavily compact the snow on the ground around the board. I have found that even this compacted snow can reach a considerable height, such that one will eventually have to crouch down quite low if they would like to look at their ruler from a height level with the board. I recommend keeping up on the shoveling around the board as much as possible throughout the winter to avoid this buildup, because it doesn't take long for the snow to reach a density akin to glacier ice, and then it can only be removed with the help of something like a pickaxe (which I've actually had to use on occasion). Along with my elevated snowboard, I will often use the more traditional method of collecting snowfall on a snowboard that is simply placed on top of the existing snowpack (or the ground if no snowpack has been established). The ground-based snowboard technique is a bit more of a hassle because it can be frustrating to try to get down level with the height of the board and get a nice look at your ruler, especially if you like to record the snowfall down to the tenths of inches. Also, ground-based snowboards have to be picked up, cleaned off, and then replaced on top of the snowpack in a nice level spot (which can sometimes be hard to find if your snowpack is disturbed by foot traffic etc.). Ground-based snowboards will also become buried after each snowfall, so one may need to flag them to find them. Finally, due to the very dry, fluffy upslope snow that we can sometimes recieve, replacing the ground-based snowboard cleanly can be a bit of a challenge because it can be hard to get the snowboard to sit on top of the snowpack without sinking in. If the snowboard sinks into the fluffy snow, the snow often sloughs in from the sides and fills the snowboard and you don't have a clean snowboard for snow collection. However, a ground-based snowboard does have a couple of advantages over an elevated one. In snowfall events at temperatures above freezing, a snowboard sitting on the snowpack will help to prevent the snow on the board from melting, since the board is cooled by the snow beneath it. The snow on an elevated board is exposed to the warm air on all sides, and will melt and compact more, resulting in a lower snowfall totals. Another advantage of a ground-based snowboard is that it may be more protected from the wind, which is something that can be quite a hassle with regard to snow collection. Fortunately, our location is down in a fairly narrow valley surrounded by lots of trees, so we don't get much wind even in the biggest storms, and that makes monitoring snowfall much easier. If wind is an issue in a location, the more accurate technique for snowfall measurement is to collect snowfall on snowboards at five separate locations and then average the results. In our case with our whole yard being very sheltered from the wind, I haven't seen the need to put out different snowboards because the accumulations of snow are very consistent throughout the property. So, my accumulations are based on my one snowboard in a fixed location.


Snowfall Measurement: I determine the depth of the new snowfall on the snowboard using similar methods to what the National Weather Service uses. I believe there are official measurement sticks for snowfall measurement, but I measure snowfall with a navigator's ruler that is incremented in tenths of an inch (instead of the more typical sixteenths), wipe the board clear, and let the snowfall accumulate again until the next measurement. There is a picture of the ruler below for those that want to see what it looks like. I guess reporting in tenths of an inch is sort of the "standard" from the guidelines I saw, but people do report in other increments (nearest inch, nearest quarter inch), and there are also tables out there on the web that list the conversion of sixteenths into tenths if you want to measure snowfall with a standard ruler. I just found it less of a hassle to buy a tenths of an inch ruler for a few bucks and use that for my measurements. The NWS snow measurement guidelines I've seen indicate that the minimum interval between measurements should be six hours, so that is the protocol I have followed. In many cases, the interval for my readings is in the 12-hour range (such as work days) or even the 24-hour range or longer (such as being away on trips). So, the snowfall I've recorded might be a bit low relative to the numbers I might have obtained if I could be at the board every six hours, but that's life unless you can always be at the board or have an automated system.

The Snowfall Data: With regard to snowfall comparisons, there are a couple of different comparisons to think about: If you want to compare the snowfall from different years at one location, just being consistent in your measurement approach will probably suffice. However, if you want to compare data that you obtain at your location to other locations, you will want to be very careful with the method you use and match the technique (especially snow measurement interval) used by the other locations or the comparison may not be very valid. Some places will take snowfall measurements only twice a day, and some will even take them only once a day. The longer the time is between measurement intervals, the more chance there is for the snow to compact or "settle", so depending on the type of snow that fell, this may make a difference. So, my data might be useful to compare snowfall in my location to what falls at the NWS office in Burlington, where they take six-hour measurements (or places like ski areas that may do the same), but it could be elevated if compared to places like the Mt. Mansfield stake or some of the stations that report the hydrological observations, where they may measure only 24-hour collections. With that said, I've done comparisons of some of my six-hour measurements to accumulations in the driveway after 12 or 24 hours, and they have been very close on the occasions I checked. But, there are probably some storms where settling will be more of an issue than others because of the snow density.

Snow Depth: I also record the depth of snow on the ground at our location using a Snow Gauge measurement device (see the first picture below). I've placed this gauge in a representative location that is open to the sky, although partially sheltered on the sides by some trees. The spot seems to be very representative of the snowpack in the yard, and is neither the first place nor the last place to melt out in the spring. This gauge stops at 30 inches, so when our snowpack gets deeper than that, I use a 4-foot metal ruler (pictured in the second image below). I also use this ruler to check the depth of the snow throughout our yard, as it is sharp and stiff enough to cut all the way down to the ground through layers of dense snow.