March 7th-8th Snowstorm Part 3
March 7-8 Snowstorm - Part 3
The numbers are in and Toronto East York, as I have predicted received more snowfall than in most regions in the city. I went outside this morning and took measurements in the park and total average snowfall is 27 cm. Environment Canada measurements throughout the city ranged from 15 cm at Toronto Pearson International Airport (west side) to around 25 cm everywhere else. The hardest hit area in the province is the Niagara Escarpment region (51 cm) and Ottawa (up to 52 cm).
Nevertheless, the snowstorm we’ve had is another testament that weather is local. If you live more than 20 km away from an airport and/or your topography has its own unique features, you’ll might experience different weather conditions. For example, we often get a bit more snow here in East York than at Pearson Airport in the west side. During summer afternoons, downtown Toronto readings are slightly cooler than further inland. It is also for this reason that Marquette, MI becomes the second snowiest major U.S. city because the official weather station moved from the city to the airport located just 12 km west and about 500 feet higher. The average snowfall for Marquette shifted from 300 cm (old location) to 457 cm. Therefore, I’m always fascinated how weather conditions vary even within a large city like Toronto. Since I live here at Sunnybrook Park, I rely on my weather station’s reading rather than at Toronto Pearson airport which is about 40 km away.
Although winter is winding down, I want to share a very important document from the National Weather Service on how to measure snow properly. I was participating in the Accuweather forum yesterday and people were sharing snowfall measurements from their backyard. However, most of them were not doing it properly such as measuring too close to the roof of their house, only taking one measurement or just reporting the drift as the absolute measurement. For this reason, I would like to share some of the guidelines from the NWS Snow Spotter Guideline booklet.
Before the First Snow
Place your snowboard outside. A snowboard can be any lightly colored board that is about 2 feet by 2 feet. A piece of plywood painted white works very well. Choose a location that is away from trees, buildings, and shadows. Try to avoid areas that are known to be prone to drifting. Mark the location of the snowboard with a stake so you can find it after a fresh snowfall.
Measuring Snowfall
Snowfall is measured to the nearest tenth of an inch (or cm in Canada). Measure the greatest amount of snowfall that has accumulated on your snowboard since the last observation. You can measure on a wooden deck or ground if a snowboard is not available. Snowfall should not be measured more than 4 times in 24 hours. If you remember back in January 11-12, 1997, Montague Township, NY reported an astonishing 24-hour snowfall of 195.6 cm of snow. Later analysis revealed, however, that measurements were conducted more than four times within 24 hours and therefore, their snowfall measurement was not considered official.
You can measure the hourly snowfall rate, but do not clean off your board each hour. Only clean off the board when you take one of the four daily measurements. Once the snow ends, add up the measurements from each time the snowboard was cleaned to reach a storm total.
Special cases:
- Snow falls and accumulates on the snowboard, but then melts. In this case, the snowfall is the greatest depth of snow observed on the board before it begins to melt. If this occurs several times, measure the snowfall after each snow shower and add each measurement for the total snowfall.
- Snow falls and melts continuously on the board. In this case, if the snow never reaches a depth of a tenth of an inch, then a trace of snowfall is recorded.
- Snow has blown or drifted onto the snowboard. In this case, take several measurements from around the yard where the snow has not drifted, being careful only to measure new snow. Take an average of the various measurements to arrive at a total.
- Sleet counts towards total snowfall, freezing rain accumulation does not.
Measuring Snow Depth
The depth of snow on the ground includes both new snow and old snow which was in place. Measure the total snow depth at several locations in your yard which have not drifted or blown. Take an average of these measurements to arrive at the snow depth. Sometimes old snow can be very hard and crusty underneath the new snow. Be sure that the ruler gets all the way down to the underlying ground. Snow depth is measured to the nearest inch (or cm in Canada).
