SupplementFirst version

18 December 2015

Updated28 July 2016

Section 1. Areas and periods shown with unrealistically deep snow (1958-2016)1
This section summarizes typical snow distributions for areas where snow was shown
as being unrealistically deep due to snow depth analysis bugs. It also includes tabulationof periods during which a significant impact is seen for each of these areas.
For more detailed information regarding the grid points where snow was shown as
being unrealistically deep, please see JRA-55_snow_hist1_update_en.txt.
1.1. Europe

Fig. 1.1. Areas shown with unrealistically deep snow in Europe for March 1981
Shading shows monthly mean snow depth, red dots represent grid points in which theinterpolation error occurred, and red circles indicate areas where snow is shown as being
unrealistically deep due to an error in snow cover climatology interpolation.
Table 1.1. Periods during which a significant impact is seen in Europe
Area
Period of significant impact (boreal winter only)1
1980/1981 to 1985/1986
2
1979/1980 to 1986/1987, 2012/2013, 2014/2015
3
1958 to 1986/1987
1 Red text indicates changes from the first version.

11.2. Western Siberia

Fig. 1.2. Areas shown with unrealistically deep snow in Western Siberia for March 1972
Shading, red dots and red circles are as per Fig. 1.1.
Table 1.2. Periods during which a significant impact is seen in Western Siberia.
Area
Period of significant impact (boreal winter only)1
1958 to 1985/1986
2
1958, 1966/1967 to 1979/1980, 1987/1988

2

1.3. East Asia

Fig. 1.3. Areas shown with unrealistically deep snow in East Asia for March 1970.
Shading, red dots and red circles are as per Fig. 1.1.
Table 1.3. Periods during which a significant impact is seen in East Asia.
Area
Period of significant impact (boreal winter only)1
1959/1960 to 1986/1987
1966/1967, 1968/1969 to 1970/1971, 1973/1974 to 1980/1981, 1985/1986,
2
1987/1988 to 1989/1990, 1991/1992 to 1999/2000, 2001/2002, 2002/2003,2005/2006, 2012/2013 to 2014/2015

3

1.4. Eastern Siberia

Fig. 1.4. Areas shown with unrealistically deep snow in Eastern Siberia for March 1985
Shading, red dots and red circles are as per Fig. 1.1. Dotted red circles indicate areas
where snow is shown as being unrealistically deep due to an error in the handling ofcoastal-area snow depth observation data.
Table 1.4. Periods during which a significant impact is seen in Eastern Siberia.
Area
Period of significant impact (boreal winter only)
1962/1963, 1965/1966, 1966/1967, 1970/1971 to 1973/1974, 1980/1981 to1
1982/1983, 1984/1985 to 1987/1988, 2013/2014
1958/1959 to 1962/1963, 1965/1966, 1980/1981, 1984/1985, 1985/1986,
2
1987/1988, 1988/1989, 1993/1994, 1995/1996, 1996/1997, 1998/1999, 2004/2005,2006/2007 to 2013/2014
3
2009/2010, 2010/2011, 2012/2013, 2013/2014, 2015/2016

41.5. Northwestern North America

Fig. 1.5. Areas shown with unrealistically deep snow in northwestern North America for
March 1965.
Shading, red dots and red circles are as per Fig. 1.1.
Table 1.5. Periods during which a significant impact is seen in northwestern North
America.
Area
Period of significant impact (boreal winter only)
1958/1959, 1964/1965 to 1966/1967, 1972/1973, 1973/1974, 1976/1977,1
1980/1981, 1983/1984 to 1990/1991, 1992/1993 to 1994/1995, 2008/2009,2011/2012, 2012/2013
1958/1959 to 1961/1962, 1964/1965 to 1966/1967, 1971/1972 to 1989/1990,2
1994/1995 to 1996/1997, 1998/1999, 2008/2009, 2009/2010
3
1958/1959, 1964/1965 to 1985/1986, 2011/2012
1958/1959 to 1961/1962, 1964/1965 to 1966/1967, 1968/1969, 1970/1971 to41975/1976, 1977/1978, 1978/1979, 1981/1982 to 1984/1985, 2006/2007 to2008/2009

5

1.6. Northern Canada

Fig. 1.6. Areas shown with unrealistically deep snow in northern Canada for March
1978.
Shading, red dots and red circles are as per Fig. 1.1.
Table 1.6. Periods during which a significant impact is seen in northern Canada.
Area
Period of significant impact (boreal winter only)1
1977/19782
1977/1978, 1980/1981 to 1982/1983, 1984/1985 to 1987/1988

6

1.7. Northeastern Canada

Fig. 1.7. Areas shown with unrealistically deep snow in northeastern Canada for March
1978.
Shading, red dots and red circles are as per Fig. 1.1.
Table 1.7. Periods during which a significant impact is seen in northeastern Canada.
Area
Period of significant impact (boreal winter only)1
1977/1978, 1978/1979, 1980/1981 to 1990/1991, 1992/1993, 1993/1994
2
1977/1978, 1978/1979, 1987/1988
31977/1978, 1985/1986, 1987/1988 to 1990/1991, 1993/1994
4
1977/1978, 1978/1979, 1980/1981 to 1983/1984, 1985/1986 to 1990/1991

7

1.8. Northeastern North America

Fig. 1.8. Areas shown with unrealistically deep snow in northeastern North America forMarch 1986.
Shading, red dots and red circles are as per Fig. 1.1. Dotted red circles indicate areas
where snow is shown as being unrealistically deep due to an error in the handing ofcoastal-area snow depth observation data.
Table 1.8. Periods during which a significant impact is seen in northeastern North
America.
Area
Period of significant impact (boreal winter only)1
1958 to 1990/1991, 1995/1996 to 1998/1999, 2003/2004 to 2005/2006, 2013/2014
2
1977/1978, 1980/1981, 1982/1983 to 1986/1987, 1992/1993, 1993/1994
3
1977/1978, 2002/2003 to 2005/2006, 2013/2014, 2014/2015
1977/1978, 1979/1980 to 1990/1991, 1992/1993 to 1994/1995, 2005/2006,4
2006/2007, 2012/2013, 2013/2014, 2015/2016
1977/1978, 1981/1982 to 1983/1984, 1998/1999, 2001/2002, 2002/2003,
5
2004/2005

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