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Found 10 records similar to Median End Date of Continuous Snow Cover
This map shows the median date of snow-cover onset (defined as the first date with 14 consecutive days of snow cover greater than 2 centimetres in depth) computed over 18 winter seasons (1979 to 1997). In areas with permanent or semipermanent snow cover (for example, Arctic ice caps) or in areas with irregular or ephemeral snow cover (coastal British Columbia), researchers were unable to compute the median values. The main feature of the map is the rapid southward extension of snow cover over Canada during the September to December period. The moderating influence of Hudson Bay can be seen over northern Quebec, where snow cover starts later than in the equivalent latitudes west of Hudson Bay.
The map shows isolines on four different dates: 1) the day of the year when there are less than or equal to 2.5 centimetres of snow that occurs and remain absent for 7 or more days; 2) the standard deviation of the mean date of snow cover loss; 3) the day of year when greater than or equal to 2.5 centimetres of snow occur and remain for more than 7 days; and 4) the standard deviation of the mean date of snow cover formation. The beginning and end of the winter season in Canada is usually identified with the formation and disappearance of snow cover in autumn and spring respectively. The duration of snow cover varies considerably from year to year in the southern fringes of the country and adjacent to the east and west coasts. However, even in northern continental areas early and late snowfalls which leave an ephemeral snow cover are common.
Contained within the 3rd Edition (1957) of the Atlas of Canada is a map that shows the snow cover data, referring primarily to the presence and total depth of a snow cover on the surface of the earth, across Canada. This is in contrast to data characteristics of snow cover depth, which increases by the occurrence of freshly fallen snow, but decreases by melting, wind action and settling. Two maps of these maps show the mean dates of the occurrence of first and last snow covers by one inch (2.54 cm) or greater. These are not necessarily the average dates to the beginning and ending of a continuous snow cover, since the snow cover may form and later disappear once or several times during a winter season.
Contained within the 4th Edition (1974) of the Atlas of Canada is a collection of five maps. Two maps show, for fertile regions, the average date of the last frost in spring and the average date of the first frost in autumn. The three remaining maps show the median depth of snow cover at a scale of 1:35 000 000 for all of Canada in inches for the dates September 30th, October 31st and November 30th.
The map shows the mean maximum depth of snow in centimetres, the standard deviation of the mean maximum depth of snow, and the mean date of mean maximum depth of snow. The information shown on the map is compiled from 1961 – 1970 snow course data in conjunction with 1955 – 1972 snow depth data. An appreciation of the quantity of snow in storage within a drainage basin during late winter is critical to spring flood forecasting. As well, decisions regarding overland transport and wildlife control can be rationally taken.
Used within the Travellers Road Information Portal Interactive Map to convey transportation related information in both official languages. Contains current winter road conditions on provincially maintained highways. For example, snow covered, snow packed, etc. This data is best viewed using Google Earth or similar Keyhole Markup Language (KML) compatible software.
Contained within the 5th Edition (1978 to 1995) of the National Atlas of Canada is a plate with seven maps. The first map shows mean annual snowfall in Canada. Four additional maps show median snow depth for four separate months. The final two maps show snow cover and maximum snow depth.
This map shows the average maximum snow depth in centimetres computed over 18 winter seasons (1979 to 1997). Over southern Canada this usually occurs in January or February, while the time of maximum accumulation occurs much later in mountain areas and in the Arctic. The main features of the map are the pronounced maximum in snow accumulation over the western Cordillera, where snow depths can exceed several metres, with a secondary maximum over Quebec and Labrador. These maxima are related to their proximity to oceans, which act as sources of moisture and winter storms, and to the orographic effect of the mountains in the case of western Canada.
Nunavut lies in the Arctic, where cold temperatures mean that snow can fall at anytime in the year. Typically the ground is snow covered from September until June. Most of Nunavut has a dry Arctic climate receiving less than 200 centimetres of snow annually.
Manual snow survey sampling from snow courses consisting of 10 measurement points. Measurements of snow water equivalent (SWE), and snow density are expressed as an average across the snow course. Measurements are taken three times a year at the start of March, April , and May.