How unusual is the current low PNW snowpack?

How unusual is the current low snowpack in the Pacific Northwest? Does it mean that this whole season is likely to be a bust?

There's seems to be some rising belief among many people that the currently well-below-normal snowpack in the Pacific Northwest is very unusual, something not seen in many years. Perhaps even more people seem to believe that the current low snowpack may portend below-normal snowfall and snowpack throughout the winter, even that the whole season may be a bust. The 11pm TV newscasts were rife with just such speculation, including major segments filmed at Snoqualmie Pass showing the thin brushy snowpack.

I suspected that these beliefs have little basis in fact, nor would they have much support in the actual snowpack data. But as a scientist, I always prefer to scrutinize the data before jumping to conclusions. So I decided to look through the NWAC's twice-monthly climatological snowdepth information (www.nwac.us/data/CLISNO) for the last 17 years, to find out how many of those seasons had significantly below-normal snowpack as of December 1 and 15, and then to see whether those seasons remained below normal overall by season's end. (Archived CLISNO data are not available on the NWAC website, but files back to 1997 have been archived on my website at www.skimountaineer.com/CascadeSki/CascadeSnowNWAC.html .)

The following list shows the years which have had a December 15 snowpack below about 70% of normal throughout these sites in Washington and northern Oregon. Although the current snowpack is well below normal, it is nevertheless well above the minimum values recorded for December 15 at most of these sites (many of the record lows are from 1976, as the 1976-77 season was a severe drought year throughout the West Coast, and the worst overall snow year over that entire region in the last 70+ years). However, new record lows for December 15 were set yesterday at Crystal Mountain base (barely) and Hurricane Ridge (by a significant margin, about half the previous minimum of 19" in 1980 -- although the actual record low appears to be 5" in 2004 as seen in that data farther below, revised values from the historical CLISNO data file I acquired several years ago courtesy of NWAC indicate that the correct depth at Hurricane Ridge on 15Dec2004 was 21").

2013-2014[size=small]
CLIMATOLOGICAL SNOWDEPTH INFORMATION                                   CLIMATOLOGICAL SNOWDEPTH INFORMATION
NORTHWEST WEATHER AND AVALANCHE CENTER SEATTLE WASHINGTON              NORTHWEST WEATHER AND AVALANCHE CENTER SEATTLE WASHINGTON
DAY  1  MONTH  12  YEAR  2013                                          DAY  15  MONTH  12  YEAR  2013
                                                                       
DATA IN INCHES, -99 DENOTES MISSING DATA                               DATA IN INCHES, -99 DENOTES MISSING DATA
                                                                       
            CURRENT  CLIMATE  PER CENT   LAST  THRU 2012  THRU 2012                CURRENT  CLIMATE  PER CENT   LAST  THRU 2012  THRU 2012
            DEPTH    AVERAGE  OF NORMAL  YEAR  MAX/YEAR   MIN/YEAR                 DEPTH    AVERAGE  OF NORMAL  YEAR  MAX/YEAR   MIN/YEAR
                                                                       
HURRICANE     5       32       16         38    70/2006     0/2002     HURRICANE    10       50       20         56    83/2006    19/1980
MT BAKER     32       49       65         51   140/1948     1/1939     MT BAKER     43       68       63         94   168/1948    16/1976
STEVENS      18       31       58         25    67/1942     0/2002     STEVENS      26       44       59         65    80/1973     5/1976
SNOQUALMIE    5       25       20         12    84/1955     0/2008     SNOQUALMIE    9       36       25         41   116/1948     0/1976
STAMPEDE      5       30       17          8    93/1945     0/2008     STAMPEDE     10       42       24         35   119/1948     9/1976
MISSION       8       17       47         16    36/1983     0/2008     MISSION      14       24       58         26    49/2006     4/1975
CRYSTAL       4       25       16         12    59/2001     0/2008     CRYSTAL       9       35       26         35    72/1996    10/1979
PARADISE     31       48       65         37   125/1994     1/2008     PARADISE     42       68       62         85   170/1948     4/1976
WHITE PASS    0       19        0          3    53/1984     0/2008     WHITE PASS    4       29       14         23    73/1996     2/1989
TIMBERLINE   21       46       46         35   137/1984     0/2002     TIMBERLINE   27       64       42         63   145/1984     0/1976
MEADOWS      18       40       45         26   113/1984     5/2008     MEADOWS      24       55       44         49   118/1984     8/1989
                                                                       
AVERAGES, MAXIMUMS AND MINIMUMS EARLY AND LATE IN THE SEASON MAY BE    AVERAGES, MAXIMUMS AND MINIMUMS EARLY AND LATE IN THE SEASON MAY BE
INACCURATE DUE TO LIMITED DATA.                                        INACCURATE DUE TO LIMITED DATA.
                                                                       
IF THERE IS TIE FOR THE MAXIMUM OR MINIMUM SNOW DEPTH THEN THE         IF THERE IS TIE FOR THE MAXIMUM OR MINIMUM SNOW DEPTH THEN THE
LATEST YEAR IS INDICATED.                                              LATEST YEAR IS INDICATED.
                                                                       
RECORDS BEGIN: HURRICANE 1979, MT BAKER 1926, STEVENS 1939,            RECORDS BEGIN: HURRICANE 1979, MT BAKER 1926, STEVENS 1939,
SNOQUALMIE 1929, STAMPEDE 1943, MISSION RIDGE 1970,                    SNOQUALMIE 1929, STAMPEDE 1943, MISSION RIDGE 1970,
CRYSTAL 1967, PARADISE 1926, WHITE PASS 1976,                          CRYSTAL 1967, PARADISE 1926, WHITE PASS 1976,
TIMBERLINE 1973, MT HOOD MEADOWS 1974.                                 TIMBERLINE 1973, MT HOOD MEADOWS 1974.
                                                                       
NOTE: NRCS DATA USED AT STAMPEDE STARTING 2006-2007 SEASON.            NOTE: NRCS DATA USED AT STAMPEDE STARTING 2006-2007 SEASON.
[/size]

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2008-2009[size=small]
CLIMATOLOGICAL SNOWDEPTH INFORMATION                                   CLIMATOLOGICAL SNOWDEPTH INFORMATION
NORTHWEST WEATHER AND AVALANCHE CENTER SEATTLE WASHINGTON              NORTHWEST WEATHER AND AVALANCHE CENTER SEATTLE WASHINGTON
DAY  1  MONTH  12  YEAR  2008                                          DAY  15  MONTH  12  YEAR  2008
                                                                       
DATA IN INCHES, -99 DENOTES MISSING DATA                               DATA IN INCHES, -99 DENOTES MISSING DATA
                                                                       
            CURRENT  CLIMATE  PER CENT   LAST  THRU 2007  THRU 2007                CURRENT  CLIMATE  PER CENT   LAST  THRU 2007  THRU 2007
            DEPTH    AVERAGE  OF NORMAL  YEAR  MAX/YEAR   MIN/YEAR                 DEPTH    AVERAGE  OF NORMAL  YEAR  MAX/YEAR   MIN/YEAR
                                                                       
HURRICANE     2       32        6         13    70/2006     0/2002     HURRICANE    20       52       38         28    83/2006    19/1980
MT BAKER      7       50       14         34   140/1948     1/1939     MT BAKER     36       68       53         52   168/1948    16/1976
STEVENS       4       32       12         21    67/1942     0/2002     STEVENS      23       44       52         39    80/1973     5/1976
SNOQUALMIE    0       25        0         17    84/1955     0/2002     SNOQUALMIE   17       36       47         33   116/1948     0/1976
STAMPEDE      0       30        0          9    93/1945     0/2002     STAMPEDE     15       44       34         22   119/1948     9/1976
MISSION       0       18        0         11    36/1983     0/2002     MISSION       6       25       24         14    49/2006     4/1975
CRYSTAL       0       25        0         20    59/2001     0/2002     CRYSTAL      22       35       63         23    72/1996    10/1979
PARADISE      1       48        2         33   125/1994     1/1976     PARADISE     45       68       66         48   170/1948     4/1976
WHITE PASS    0       20        0         19    53/1984     0/2002     WHITE PASS   20       29       69          8    73/1996     2/1989
TIMBERLINE    5       46       11         38   137/1984     0/2002     TIMBERLINE   35       65       54         38   145/1984     0/1976
MEADOWS       5       40       12         41   113/1984     7/2004     MEADOWS      29       56       52         38   118/1984     8/1989
[/size]

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2007-2008[size=small]
CLIMATOLOGICAL SNOWDEPTH INFORMATION                                   CLIMATOLOGICAL SNOWDEPTH INFORMATION
NORTHWEST WEATHER AND AVALANCHE CENTER SEATTLE WASHINGTON              NORTHWEST WEATHER AND AVALANCHE CENTER SEATTLE WASHINGTON
DAY  1  MONTH  12  YEAR  2007                                          DAY  15  MONTH  12  YEAR  2007
                                                                       
DATA IN INCHES, -99 DENOTES MISSING DATA                               DATA IN INCHES, -99 DENOTES MISSING DATA
                                                                       
            CURRENT  CLIMATE  PER CENT   LAST  THRU 2006  THRU 2006                CURRENT  CLIMATE  PER CENT   LAST  THRU 2006  THRU 2006
            DEPTH    AVERAGE  OF NORMAL  YEAR  MAX/YEAR   MIN/YEAR                 DEPTH    AVERAGE  OF NORMAL  YEAR  MAX/YEAR   MIN/YEAR
                                                                       
HURRICANE    13       33       39         70    70/2006     0/2002     HURRICANE    28       53       53         83    83/2006    19/1980
MT BAKER     34       50       68        117   140/1948     1/1939     MT BAKER     52       68       76        113   168/1948    16/1976
STEVENS      21       32       66         55    67/1942     0/2002     STEVENS      39       44       89         77    80/1973     5/1976
SNOQUALMIE   17       25       68         51    84/1955     0/2002     SNOQUALMIE   33       36       92         60   116/1948     0/1976
STAMPEDE      9       31       29        -99    93/1945     0/2002     STAMPEDE     22       44       50        -99   119/1948     9/1976
MISSION      11       18       61         19    36/1983     0/2002     MISSION      14       25       56         49    49/2006     4/1975
CRYSTAL      20       25       80         55    59/2001     0/2002     CRYSTAL      23       35       66         56    72/1996    10/1979
PARADISE     33       48       69        -99   125/1994     1/1976     PARADISE     48       68       71         90   170/1948     4/1976
WHITE PASS   19       20       95         40    53/1984     0/2002     WHITE PASS    8       30       27        -99    73/1996     2/1989
TIMBERLINE   38       46       83         83   137/1984     0/2002     TIMBERLINE   38       65       58         73   145/1984     0/1976
MEADOWS      41       40      102         69   113/1984     7/2004     MEADOWS      38       56       68         66   118/1984     8/1989
[/size]

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2004-2005[size=small]
CLIMATOLOGICAL SNOWDEPTH INFORMATION                                   CLIMATOLOGICAL SNOWDEPTH INFORMATION
NORTHWEST WEATHER AND AVALANCHE CENTER                                 NORTHWEST WEATHER AND AVALANCHE CENTER
ISSUED THROUGH NATIONAL WEATHER SERVICE SEATTLE                        ISSUED THROUGH NATIONAL WEATHER SERVICE SEATTLE
                                                                       
FOR : DAY  1  MONTH  12  YEAR  2004                                    FOR : DAY  15  MONTH  12  YEAR  2004
                                                                       
DATA IN INCHES, -99 DENOTES MISSING DATA                               DATA IN INCHES, -99 DENOTES MISSING DATA
                                                                       
            CURRENT  CLIMATE  PER CENT   LAST  THRU 2003  THRU 2003                CURRENT  CLIMATE  PER CENT   LAST  THRU 2003  THRU 2003
            DEPTH    AVERAGE  OF NORMAL  YEAR  MAX/YEAR   MIN/YEAR                 DEPTH    AVERAGE  OF NORMAL  YEAR  MAX/YEAR   MIN/YEAR
                                                                       
HURRICANE     5       32       16         33    64/1994     0/2002     HURRICANE     5       55        9         62    80/1996    19/1980
MT BAKER     25       49       51         72   140/1948     1/1939     MT BAKER     40       68       59        106   168/1948    16/1976
STEVENS      13       31       42         41    67/1942     0/2002     STEVENS      22       44       50         72    80/1973     5/1976
SNOQUALMIE   10       25       40         30    84/1955     0/2002     SNOQUALMIE   11       36       31         68   116/1948     0/1976
STAMPEDE    -99       31      -99         33    93/1945     0/2002     STAMPEDE     12       45       27         66   119/1948     9/1976
MISSION       1       19        5         16    36/1983     0/2002     MISSION       6       25       24         29    47/1983     4/1975
CRYSTAL       6       25       24         29    59/2001     0/2002     CRYSTAL      13       35       37         51    72/1996    10/1979
PARADISE     25       48       52         59   125/1994     1/1976     PARADISE     36       69       52        103   170/1948     4/1976
WHITE PASS    5       19       26         17    53/1984     0/2002     WHITE PASS    4       31       13         47    73/1996     2/1989
TIMBERLINE   28       46       61         50   137/1984     0/2002     TIMBERLINE   44       66       67         89   145/1984     0/1976
MEADOWS       7       41       17         36   113/1984     8/2002     MEADOWS      19       57       33         61   118/1984     8/1989
[/size]

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2002-2003[size=small]
CLIMATOLOGICAL SNOWDEPTH INFORMATION                                   CLIMATOLOGICAL SNOWDEPTH INFORMATION
NORTHWEST WEATHER AND AVALANCHE CENTER                                 NORTHWEST WEATHER AND AVALANCHE CENTER
ISSUED THROUGH NATIONAL WEATHER SERVICE SEATTLE                        ISSUED THROUGH NATIONAL WEATHER SERVICE SEATTLE
                                                                       
FOR : DAY  1  MONTH  12  YEAR  2002                                    FOR : DAY  15  MONTH  12  YEAR  2002
                                                                       
DATA IN INCHES, -99 DENOTES MISSING DATA                               DATA IN INCHES, -99 DENOTES MISSING DATA
                                                                       
            CURRENT  CLIMATE  PER CENT   LAST  THRU 2001  THRU 2001                CURRENT  CLIMATE  PER CENT   LAST  THRU 2001  THRU 2001
            DEPTH    AVERAGE  OF NORMAL  YEAR  MAX/YEAR   MIN/YEAR                 DEPTH    AVERAGE  OF NORMAL  YEAR  MAX/YEAR   MIN/YEAR
                                                                       
MT BAKER     16       49       33         58   140/1948     1/1939     MT BAKER     31       68       46        104   168/1948    16/1976
STEVENS       0       32        0         37    67/1942     0/1941     STEVENS      19       44       43         66    80/1973     5/1976
SNOQUALMIE    0       25        0         44    84/1955     1/1969     SNOQUALMIE   12       36       33         61   116/1948     0/1976
STAMPEDE      0       31        0         41    93/1945     0/1976     STAMPEDE    -99       44      -99        -99   119/1948     9/1976
PARADISE      8       48       17         68   125/1994     1/1976     PARADISE     36       69       52        114   170/1948     4/1976
WHITE PASS    0       20        0         30    53/1984     1/1999     WHITE PASS   12       31       39         42    73/1996     2/1989
MT HOOD       8       43       19         60   113/1984    10/1995     MT HOOD      10       59       17        110   118/1984     8/1989
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1997-1998[size=small]
CLIMATOLOGICAL SNOWDEPTH INFORMATION                                   CLIMATOLOGICAL SNOWDEPTH INFORMATION
NORTHWEST WEATHER AND AVALANCHE CENTER                                 NORTHWEST WEATHER AND AVALANCHE CENTER
ISSUED THROUGH NATIONAL WEATHER SERVICE SEATTLE                        ISSUED THROUGH NATIONAL WEATHER SERVICE SEATTLE
                                                                       
DAY  1  MONTH  12  YEAR  1997                                          DAY  15  MONTH  12  YEAR  1997
                                                                       
DATA IN INCHES, -99 DENOTES MISSING DATA                               DATA IN INCHES, -99 DENOTES MISSING DATA
                                                                       
            CURRENT     CLIMATE     PER CENT      THIS DATE                        CURRENT     CLIMATE     PER CENT      THIS DATE
             DEPTH      AVERAGE     OF NORMAL     LAST YEAR                         DEPTH      AVERAGE     OF NORMAL     LAST YEAR
                                                                       
MT BAKER       21            49            43            50            MT BAKER       33            67            49            130
STEVENS        18            32            56            41            STEVENS        25            44            57            70
SNOQUALMIE     8             25            32            35            SNOQUALMIE     16            35            46            72
STAMPEDE       10            32            31            49            STAMPEDE       20            45            44            77
PARADISE       48            48            100           77            PARADISE       51            68            75            130
WHITE PASS     12            22            55            35            WHITE PASS     16            32            50            73
MT HOOD        19            45            42            46            MT HOOD        28            58            48            116
[/size]

So 6 years out of the past 17 (including this year) have had a December 15 snowpack below roughly 70% of normal throughout these sites, with 3 of those years below roughly 60% of normal (2013, 2004, 2002). This is a fairly small set of data, but it certainly appears that well-below-normal snowpacks as of December 15 occur approximately every 3-5 years, with snowpacks as low as the current one occurring 1-2 times per decade. Therefore the current low snowpack is not really that unusual.


[size=small](Note: these posts were split due to the 20,000 character limit per post)[/size]

So how strongly does a well-below-normal December 15 snowpack correlate with an overall low snowfall and low snowpack throughout the winter and spring?

The standard one-parameter measure of an entire season's snowpack is the April 1 snowdepth, which correlates well with total season snowfall at these type of high-snowfall mountain sites. Shown below are the April 1 and April 15 CLISNO data recorded 4 months later on in each of the seasons shown above (except the current season, obviously). Snowfall totals for the entire season are also shown, along with calculated percents of normal, for the only 3 of these sites where such data is readily available.

2008-2009 -- weak La Niña[size=small]
CLIMATOLOGICAL SNOWDEPTH INFORMATION                                   CLIMATOLOGICAL SNOWDEPTH INFORMATION
NORTHWEST WEATHER AND AVALANCHE CENTER SEATTLE WASHINGTON              NORTHWEST WEATHER AND AVALANCHE CENTER SEATTLE WASHINGTON
DAY  1  MONTH  4  YEAR  2009                                           DAY  15  MONTH  4  YEAR  2009
                                                                       
DATA IN INCHES, -99 DENOTES MISSING DATA                               DATA IN INCHES, -99 DENOTES MISSING DATA
                                                                       
            CURRENT  CLIMATE  PER CENT   LAST  THRU 2008  THRU 2008                CURRENT  CLIMATE  PER CENT   LAST  THRU 2008  THRU 2008
            DEPTH    AVERAGE  OF NORMAL  YEAR  MAX/YEAR   MIN/YEAR                 DEPTH    AVERAGE  OF NORMAL  YEAR  MAX/YEAR   MIN/YEAR
                                                                       
HURRICANE    93      106       88        137   252/1999    42/2005     HURRICANE    92      110       84        122   252/1999    51/2005
MT BAKER    143      174       82        197   311/1999    72/1934     MT BAKER    145      167       87        185   290/1999    56/1934
STEVENS     115      101      114        131   192/1956    24/1941     STEVENS     102       93      110        116   170/1956    17/1941
SNOQUALMIE  102       86      119        131   170/1956     2/1992     SNOQUALMIE   89       72      124        121   153/1974     0/1992
STAMPEDE    127      100      127        144   183/1956    17/1992     STAMPEDE    111       98      113        131   216/1964     9/1992
MISSION      49       46      107         55    86/1983    20/1973     MISSION      44       45       98         45    79/1983    21/1990
CRYSTAL      93       70      133        105   144/1999    16/1981     CRYSTAL      87       72      121         98   130/1999    30/1981
PARADISE    185      175      106        240   327/1956    66/1941     PARADISE    176      172      102        213   302/1972    68/1934
WHITE PASS   98       54      181         95   110/1997     0/1992     WHITE PASS   65       44      148         80    95/1997     0/1992
TIMBERLINE  199      163      122        225   300/1999    57/1981     TIMBERLINE  211      162      130        226   300/1999    71/1977
MEADOWS     166      128      130        199   199/2008    49/2005     MEADOWS     160      125      128        194   194/2008    54/2005

Snowfall:    Season    Climate     % of
              Total    Average    Normal
MT BAKER       548       620        88%
SNOQUALMIE     433       430       101%
PARADISE       734       650       113%
[/size]

---

2007-2008 -- strong La Niña[size=small]
CLIMATOLOGICAL SNOWDEPTH INFORMATION                                   CLIMATOLOGICAL SNOWDEPTH INFORMATION
NORTHWEST WEATHER AND AVALANCHE CENTER SEATTLE WASHINGTON              NORTHWEST WEATHER AND AVALANCHE CENTER SEATTLE WASHINGTON
DAY  1  MONTH  4  YEAR  2008                                           DAY  15  MONTH  4  YEAR  2008
                                                                       
DATA IN INCHES, -99 DENOTES MISSING DATA                               DATA IN INCHES, -99 DENOTES MISSING DATA
                                                                       
            CURRENT  CLIMATE  PER CENT   LAST  THRU 2007  THRU 2007                CURRENT  CLIMATE  PER CENT   LAST  THRU 2007  THRU 2007
            DEPTH    AVERAGE  OF NORMAL  YEAR  MAX/YEAR   MIN/YEAR                 DEPTH    AVERAGE  OF NORMAL  YEAR  MAX/YEAR   MIN/YEAR
                                                                       
HURRICANE   137      104      132        108   252/1999    42/2005     HURRICANE   122      109      112        104   252/1999    51/2005
MT BAKER    197      174      113        180   311/1999    72/1934     MT BAKER    185      166      111        168   290/1999    56/1934
STEVENS     131      100      131         95   192/1956    24/1941     STEVENS     116       93      125         90   170/1956    17/1941
SNOQUALMIE  131       85      154         79   170/1956     2/1992     SNOQUALMIE  121       71      170         65   153/1974     0/1992
STAMPEDE    144      100      144         88   183/1956    17/1992     STAMPEDE    131       98      134         88   216/1964     9/1992
MISSION      55       46      120         41    86/1983    20/1973     MISSION      45       45      100         36    79/1983    21/1990
CRYSTAL     105       69      152         80   144/1999    16/1981     CRYSTAL      98       71      138         75   130/1999    30/1981
PARADISE    240      174      138        141   327/1956    66/1941     PARADISE    213      172      124        147   302/1972    68/1934
WHITE PASS   95       53      179         51   110/1997     0/1992     WHITE PASS   80       42      190         35    95/1997     0/1992
TIMBERLINE  225      161      140        143   300/1999    57/1981     TIMBERLINE  226      160      141        147   300/1999    71/1977
MEADOWS     199      125      159        104   199/1999    49/2005     MEADOWS     194      123      158        100   190/1982    54/2005

Snowfall:    Season    Climate     % of
              Total    Average    Normal
MT BAKER       786       620       127%
SNOQUALMIE     591       430       137%
PARADISE       947       650       146%
[/size]

---

2004-2005 -- weak El Niño[size=small]
CLIMATOLOGICAL SNOWDEPTH INFORMATION                                   CLIMATOLOGICAL SNOWDEPTH INFORMATION
NORTHWEST WEATHER AND AVALANCHE CENTER SEATTLE WASHINGTON              NORTHWEST WEATHER AND AVALANCHE CENTER SEATTLE WASHINGTON
DAY  1  MONTH  4  YEAR  2005                                           DAY  15  MONTH  4  YEAR  2005
                                                                       
DATA IN INCHES, -99 DENOTES MISSING DATA                               DATA IN INCHES, -99 DENOTES MISSING DATA
                                                                       
            CURRENT  CLIMATE  PER CENT   LAST  THRU 2004  THRU 2004                CURRENT  CLIMATE  PER CENT   LAST  THRU 2004  THRU 2004
            DEPTH    AVERAGE  OF NORMAL  YEAR  MAX/YEAR   MIN/YEAR                 DEPTH    AVERAGE  OF NORMAL  YEAR  MAX/YEAR   MIN/YEAR
                                                                       
HURRICANE    42      106       40         95   252/1999    48/1981     HURRICANE    51      112       46         81   252/1999    65/2001
MT BAKER     78      175       45        159   311/1999    72/1934     MT BAKER     79      167       47        138   290/1999    56/1934
STEVENS      49      101       49         79   192/1956    24/1941     STEVENS      39       94       41         61   170/1956    17/1941
SNOQUALMIE   25       86       29         69   170/1956     2/1992     SNOQUALMIE   16       72       22         35   153/1974     0/1992
STAMPEDE     35      101       35         77   183/1956    17/1992     STAMPEDE     26       99       26         52   216/1964     9/1992
MISSION      21       47       45         44    86/1983    20/1973     MISSION      22       47       47         35    79/1983    21/1990
CRYSTAL      31       69       45         83   144/1999    16/1981     CRYSTAL      36       71       51         69   130/1999    30/1981
PARADISE     92      175       53        169   327/1956    66/1941     PARADISE     91      173       53        147   302/1972    68/1934
WHITE PASS   15       54       28         54   110/1997     0/1992     WHITE PASS    3       43        7         25    95/1997     0/1992
TIMBERLINE   74      164       45        182   300/1999    57/1981     TIMBERLINE   88      162       54        163   300/1999    71/1977
MEADOWS      49      127       39        126   199/1999    55/1992     MEADOWS      54      125       43        114   190/1982    54/1992

Snowfall:    Season    Climate     % of
              Total    Average    Normal
MT BAKER       465       620        75%
SNOQUALMIE     216       430        50%
PARADISE       409       650        63%
[/size]

---

2002-2003 -- moderate El Niño[size=small]
NOTE: The CLISNO expanded from 7 sites to 11 sites as of March 15, 2003

CLIMATOLOGICAL SNOWDEPTH INFORMATION                                   CLIMATOLOGICAL SNOWDEPTH INFORMATION
NORTHWEST WEATHER AND AVALANCHE CENTER                                 NORTHWEST WEATHER AND AVALANCHE CENTER
ISSUED THROUGH NATIONAL WEATHER SERVICE SEATTLE                        ISSUED THROUGH NATIONAL WEATHER SERVICE SEATTLE
                                                                       
FOR : DAY  1  MONTH  4  YEAR  2003                                     FOR : DAY  15  MONTH  4  YEAR  2003
                                                                       
DATA IN INCHES, -99 DENOTES MISSING DATA                               DATA IN INCHES, -99 DENOTES MISSING DATA
                                                                       
            CURRENT  CLIMATE  PER CENT   LAST  THRU 2002  THRU 2002                CURRENT  CLIMATE  PER CENT   LAST  THRU 2002  THRU 2002
            DEPTH    AVERAGE  OF NORMAL  YEAR  MAX/YEAR   MIN/YEAR                 DEPTH    AVERAGE  OF NORMAL  YEAR  MAX/YEAR   MIN/YEAR
                                                                       
HURRICANE    94      107       88        133   252/1999    48/1981     HURRICANE    95      115       83        123   252/1999    65/2001
MT BAKER    171      175       98        186   311/1999    72/1934     MT BAKER    148      168       88        168   290/1999    56/1934
STEVENS      84      102       82        132   192/1956    24/1941     STEVENS      78       95       82        117   170/1956    17/1941
SNOQUALMIE   50       86       58        112   170/1956     2/1992     SNOQUALMIE   42       73       58        100   153/1974     0/1992
STAMPEDE     72      102       71        134   183/1956    17/1992     STAMPEDE    -99      100      -99        -99   216/1964     9/1992
MISSION      49       47      104         54    86/1983    20/1973     MISSION      45       49       92         45    79/1983    21/1990
CRYSTAL      76       69      110         96   144/1999    16/1981     CRYSTAL      70       71       99         82   130/1999    30/1981
PARADISE    151      175       86        220   327/1956    66/1941     PARADISE    155      173       90        200   302/1972    68/1934
WHITE PASS   42       54       78         76   110/1997     0/1992     WHITE PASS   30       45       67         55    95/1997     0/1992
TIMBERLINE  168      163      103        253   300/1999    57/1981     TIMBERLINE  175      161      109        220   300/1999    71/1977
MEADOWS     100      124       81        167   199/1999    55/1992     MEADOWS      99      122       81        146   190/1982    54/1992

Snowfall:    Season    Climate     % of
              Total    Average    Normal
MT BAKER       586       620        95%
SNOQUALMIE     277       430        64%
PARADISE       603       650        93%
[/size]

---

1997-1998 -- very strong El Niño[size=small]
CLIMATOLOGICAL SNOWDEPTH INFORMATION                                   CLIMATOLOGICAL SNOWDEPTH INFORMATION
NORTHWEST WEATHER AND AVALANCHE CENTER                                 NORTHWEST WEATHER AND AVALANCHE CENTER
ISSUED THROUGH NATIONAL WEATHER SERVICE SEATTLE                        ISSUED THROUGH NATIONAL WEATHER SERVICE SEATTLE
                                                                       
DAY  1  MONTH  4  YEAR  1998                                           DAY  15  MONTH  4  YEAR  1998
                                                                       
DATA IN INCHES, -99 DENOTES MISSING DATA                               DATA IN INCHES, -99 DENOTES MISSING DATA
                                                                       
            CURRENT     CLIMATE     PER CENT      THIS DATE                        CURRENT     CLIMATE     PER CENT      THIS DATE
             DEPTH      AVERAGE     OF NORMAL     LAST YEAR                         DEPTH      AVERAGE     OF NORMAL     LAST YEAR
                                                                       
MT BAKER       163           174           94            205           MT BAKER       154           167           92            200
STEVENS        80            101           79            158           STEVENS        78            94            83            145
SNOQUALMIE     77            86            90            146           SNOQUALMIE     65            72            90            124
STAMPEDE       77            102           75            153           STAMPEDE       71            100           71            135
PARADISE       163           174           94            243           PARADISE       166           172           97            250
WHITE PASS     62            50            124           110           WHITE PASS    -99            42           -99            95
MT HOOD        120           120           100           177           MT HOOD        127           119           107           167

Snowfall:    Season    Climate     % of
              Total    Average    Normal
MT BAKER        -        620        -
SNOQUALMIE     361       430        84%
PARADISE       674       650       104%
[/size]

So out of these 5 previous seasons since 1997 with a December 15 snowpack below roughly 70% of normal at these sites, one season ended up being huge (2007-2008, a memorable strong La Niña year), one slightly above-normal (2008-2009, weak La Niña), 2 near-normal (2002-2003, moderate El Niño, and 1997-98, very strong El Niño), and one well-below-normal (2004-2005, weak El Niño, the worst snow year in the Northwest since 1976-77, even since 1940-41 at some sites). Of course, at Snoqualmie Pass (the lowest elevation among these sites) these seasons look more below normal than at higher-elevations sites like Paradise or Baker.

Therefore at most of these sites, there appears to be hardly any correlation between low December 15 snowpack and an overall low snowfall / snowpack throughout the entire season, although there is a definite correlation in that direction at Snoqualmie Pass (albeit weak). Statistically, it is unlikely that this season will end up having catastrophically low snowfall, although that is obviously a possibility in almost any year (except in strong La Niña years, which have near-zero chance of being below normal in the Northwest). The likelihood of a below-normal season at Snoqualmie Pass is clearly greater than at other higher-elevation sites, but that is often the case in many seasons, as Snoqualmie is a very risky basket in which to keep one's wintertime eggs.

The most likely outcome this season is near-normal or perhaps slightly below-normal (i.e. 80-90% of normal snowfall and April 1 snowpack, which is still huge and far beyond what any other regions in the lower 48 normally get). There also remains a significant chance that the season could even end up being above-normal overall, although the likelihood of ending up far-above-normal is quite small given the lack of La Niña conditions in the Pacific (currently ENSO neutral, although SST anomalies have remained slightly negative throughout 2013, see www.cpc.ncep.noaa.gov/products/precip/CW...nso.shtml#discussion).

Anyway, it's already been a great season so far, with the most late-September snowfall since at least 1972 providing excellent early-October ski conditions, followed by many periods of beautiful sunny weather to enjoy the powder and the corn throughout the autumn months -- and winter hasn't even arrived yet. 


[size=small]Skiing drifts of windblown powder above the sea of clouds, Mount Rainier, December 9, 2013.[/size]


[size=small](Edited to list the ENSO character for each of these 5 seasons.)[/size]

Thanks for doing the science! Beautiful pic too!

After all the statistics however it seems a bit disingenuous and overstated to be labeling Snoqualmie as a "a very risky basket." Even comparing it relatively as you do it still delivers quite nicely. It also remains the ski option with the lowest carbon footprint to the largest metropolitan area in the state of Washington. Given the accumulating science of emissions on weather patterns and the driving required* to access skiing, this to me would seem pertinent and anything but risky. Not to mention the character building aspect... it's not for nothing all the best skiers cut their teeth in snocrummy land.


*with the exception of course of the occasional entirely human powered ski excursion

Cliff mass had a great explanation post for the current situation

cliffmass.blogspot.com/2013/12/an-unusually-dry-fall.html

Thanks for pulling all that data!  Really interesting to see.

Thanks for confirming my hypotheses, Amar! While we're off to a slow start, that doesn't mean we won't still have a great season. It's all about perspective and making the best out of the hand we've been dealt.

As a recent transplant to the region (~7 years ago), it's easy to falsely generalize about the current state of the snowpack, weather patterns, etc. Climate operates on the scale of decades, what we're seeing is likely within the overall error range / uncertainty.

While I dodged the bullet in 2004-2005, the slow starts of 2007-2008 and 2008-2009 are still fresh in my memory. IMHO, the season starts when Mt. Baker opens and ends when the base of Alpental melts out. In 2008-2009, Mt. Baker didn't open until Dec. 14 and I recall Ski Patrol opening the 7th Heaven chairlift at Steven's Pass on Christmas Day. In 2007-2008, Mt. Baker barely made it open before December (Nov. 29th), but if you recall it snowed 13+ feet in March at Snoqualmie Pass and Alpental spun their lifts until early June!

So while we're certainly off to a slow start, just take a deep breath and put it into scientific perspective. There's still plenty of time for Old Man Winter to deliver...

There have been a lot of winters that have been saved by about three weeks of intensive snowfalls. That has been a situation for some time now. The one recent year where that didn't happen was 2004-2005 with very low snowpacks throughout. Even in bad winters, which this one currently looks like, the long wave pattern usually changes between about mid-February and early March when low pressure tends to form and persist over the Queen Charlottes.

The CPC www.cpc.ncep.noaa.gov/products/predictio.../seasonal.php?lead=5 still shows equal chances for precipitation each month through mid-late spring but also shows below normal temperatures for essentially the whole of that period over the Northwest. That implies a ridge west of the region with precipitation occurring when the ridge of high pressure either flattens or the axis moves sufficiently offshore to allow for toughing along the coast. Long term forecasts (you can read about the methodology on the CPC website) are based primarily on climatology, recent weather patterns and sea surface temperature forecasts.

That said I don't feel overly confident about snowpack and conditions until mid-late winter. But three weeks of snowfall could once again change much of that.

that is what i have been telling myself, amar.
b

All it would take is one good storm cycle in the next few weeks and everyone will start talking about a global ice age, the dawn of a new golden age of low elevation snow pack, skiing lines that "never form this early", etc, etc.

I kid, but seriously. One good damp maritime snowfall of 20-30" or so on the crest and I think any coverage issues we're having will be forgotten.

One other interesting weather anomaly. I live in Plain and work in Leavenworth. Sunday in Plain it warmed up to 55 degrees and melted basically all the snow in the Plain/Lake Wenatchee area. Save for some shaded areas where peoples roofs shed snow, it looks like spring. I was expecting the same in Leavenworth, but to my surprise Leavenworth still is white with snow on the trees and no loss of snow pack. For a frame of reference, Plain is nearly 1000 ft higher and gets nearly double the amount of snow.

Question is, what caused this? Inversion layer or protective Bavarian snow voodoo magic net cast by the Leavenworth Chamber of Commerce over Christmas Town??? Tin foil hat stuff here people.

We sure would benefit if the high pressure would move along and return a more typical pattern. I'm just watching the Aleutian chain area / north mid pacific and hoping to see some tight, developed lows form with a shift in the aloft air. Three or four of those rolling in will change the game. Making lemonade when ya get lemons? The retail market gets nervous by mid January if this goes on til then.

Question is, what caused this? Inversion layer or protective Bavarian snow voodoo magic net cast by the Leavenworth Chamber of Commerce over Christmas Town??? Tin foil hat stuff here people.

Very unscientificaly, I would posit that the cool easterly flow and inversions have saved the snow in 11worth, while the elevation and relatively deeper snowpack has kept the snow as you move up to the pass. Definitely a strange effect indeed.


Also, even though pass level snowpack is low I'm guessing higher elevation snowpack is at least near average. We've had some strong precipitation events; unfortunately its been pretty warm during a lot of it.

Single malt and a new pair of trail running shoes...

All I want for Christmas ...

... is a dump of 2+ feet!

Also, Amar's famous! From today's Mt. Baker Ski Area Snow Report :

According to a recent in depth study by University of Washington scientist Amar Andalkar, the weather that has occurred through mid December has very little to do with the upcoming weather for the rest of the winter season. He expects the most likely scenario is both near normal snowfall and April 1st snowpack, which is a huge amount of snow and far beyond other regions in the lower 48 states. Keep doing your best snowdance!

Amar's post made me want to make some graphs to take a look at the trend visually.


(numbers indicate years since 1900, thus year 113 was last year).

In general, mid-december snowpack (snow water equivalent) is correlated with April snowpack.  However, there's still lots of season left to make up for a poor start.  One way you might assess that is to look at the correlation between each month, and see how quickly it drops off.  In the graphs below, the brighter the green, the stronger the correlation.  You can see that for Stampede Pass and Paradise, the horizontal band of green at Dec 16 doesn't extend as far as it does when you follow January 16 out to the right (for instance).





I would interpret this as saying that often our heaviest snowfalls will come after the new year. However, once we run out of winter (March 1), we essentially will only maintain the snowpack, rather than have any more chance to build it.

Interestingly, in sites to the east of the crest, early season correlations appear to have a stronger influence on the late season.  At Hart's Pass,  even Nov 16 snowpack appears to correlate with May snowpack.  This may be because it is the coldest (receiving air from the BC interior), and highest site I considered.  This actually might also be true for Stampede Pass, which also seems to have more persistent correlations than Stevens Pass.

Methods:
I downloaded bi-monthly snow water equivalent from snotel using their report generator .  Records were from 1981-December 2013, except for a couple sites where records started in the mid-80s.
I defined the water year to be July1-Jun 31st (which I think is standard?).  If anyone is curious, here's some links to the data I used to generate the plots.

awesome analysis Amar, I love geeking out on hydrologic data. Thanks for putting the numbers to it.

Nice supplement andyrew...just FYI water years go from Oct1-Sept30. Roughly correlates to the break point at which rivers ceases running from the previous winter's snowpack, or vice-versa, when the rivers could begin running from fresh snowfall.

In the meantime, less bitching, more praying for snow!

Andyrew,
There has been a short term (<10 yr) shift towards later-season (post March 15) snowpack accumulation that would get buried in the noise of a longer historical analysis. IIRC, this affect appears to be more pronounced during El Nino years. Last time I checked (at least a year ago) no one in the field really knew why this was, but I believe a play between the various pacific ocillations (PDO/IPO) was a suspect.

Another analysis that would be fascinating is your correlation extended to basin-wide SWE models. Sometimes these tell a different story than individual SNOTEL sites because they are less susceptible to single-point conditions. I feel like your Hart's Pass analysis hints total SWE for a large portion of the Cascades may correlate rather strongly, because so much of our terrain is higher than the average SNOTEL site.

I love that some real analysis is going on at TAY!

While Amar’s analysis of past snowfall history is interesting, it should not be construed to imply a most likely outcome of this year’s snowpack.  What it does show is that this winter is similar to winters that have been observed in the past.  If you believe the climate modelers, what has been normal or typical in the past will become very abnormal in the near future. Correlations made now with past weather events will become meaningless in predicting the future.  It is quite possible that within the next few years we will begin to notice a very different regime of temperature and snowfall in the Cascades. That change could already be happening.

While Amar’s analysis of past snowfall history is interesting, it should not be construed to imply a most likely outcome of this year’s snowpack.  What it does show is that this winter is similar to winters that have been observed in the past.  If you believe the climate modelers, what has been normal or typical in the past will become very abnormal in the near future. Correlations made now with past weather events will become meaningless in predicting the future.  It is quite possible that within the next few years we will begin to notice a very different regime of temperature and snowfall in the Cascades. That change could already be happening.

[size=small](emphasis added)[/size]

Is that really what the climate modelers are saying? Not really, or at least that's a severe exaggeration of what most (scientifically peer-reviewed, published, etc.) climate modelers are saying. But I suspect you know that already, and are just being hyperbolic and alarmist (although some degree of alarm over anthropogenic climate change is probably warranted).

With apologies (since I dislike it when others do this), I've slightly reworded the last 4 sentences to give a more reasonable view that better reflects current climate scientists' consensus:
"If you believe the climate modelers, what has been normal or typical in the past will become very abnormal less typical or normal in the near future over the next century. Correlations made now with past weather events will become meaningless less reliable in predicting the future.  It is quite possible that within the next few years decades we will begin to notice a very different slightly but increasingly different regime of temperature and snowfall in the Cascades. That change could already be happening."

My main point is that, especially considering the (very limited) 17 year set of data I presented, the effects of climate change are unlikely to be significant or detectable in regards to predicting likely snowpack outcomes for this season. The effects due to smaller-time-scale variability such as PDO (period of decades), ENSO (period of years), and MJO (period of months) are much more significant for this season and the next several too than that of climate change.

Amar's post made me want to make some graphs to take a look at the trend visually.

(numbers indicate years since 1900, thus year 113 was last year).

In general, mid-december snowpack (snow water equivalent) is correlated with April snowpack.

I like it -- I was originally thinking of making a plot very similar to this and calculating linear correlation coefficients and all that, using long-term data from Paradise (since 1916), Crater Lake (since 1919), Holden Village (since 1962), perhaps a few other mountain sites where I could get long-term data (50+ years) from the National Climatic Data Center (unfortunately there are very few such sites) -- but then I just decided to take a look at the NWAC's CLISNO tables, since those sites are most relevant for skiers in this region.

Although there is an obvious correlation in the graph, it is fairly weak (i.e. the lines are fairly flat in slope, and the y-intercepts are strongly non-zero) at all except Harts Pass. Looking at the data points pretty much supports the conclusion I reached in the original post above. Taking just the Paradise data (most of the uppermost data points), April 1 snowpacks in the near-normal range (say 65-85" of SWE) are found in seasons which have December 15 snowpacks ranging from 9" to 37" -- that's a vast range of December 15 snowpacks, covering the full gamut from far-below-normal to far-above-normal, all of which produced near-normal April 1 snowpacks! (On a side note, it's worth mentioning that the Paradise SNOTEL site is at 5130 ft, significantly lower than the Paradise NWAC site and where the NPS manually records daily data, 5420 ft.) The effect is less easy to discern for the other sites shown in the graph, and the correlation is stronger than for Paradise in each case, but near-normal April 1 snowpacks still occur over a wide range of December 15 snowpack depths at those sites too.

I would interpret this as saying that often our heaviest snowfalls will come after the new year. However, once we run out of winter (March 1), we essentially will only maintain the snowpack, rather than have any more chance to build it.

Interestingly, in sites to the east of the crest, early season correlations appear to have a stronger influence on the late season.  At Hart's Pass,  even Nov 16 snowpack appears to correlate with May snowpack.  This may be because it is the coldest (receiving air from the BC interior), and highest site I considered.  This actually might also be true for Stampede Pass, which also seems to have more persistent correlations than Stevens Pass.

We definitely don't run out of winter on March 1, at least not at reasonable elevations in the Cascades. At most sites above about 4000 ft in the WA Cascades (i.e NOT Snoqualmie in particular), 5000 ft in the OR Cascades, and 6000 ft in the CA Cascades, the month which has the highest ratio of average snowfall to average precipitation is March! Not January or February! (Several years ago, I analyzed data from many dozens of sites from SW BC all the way to the southern Sierra Nevada, calculating snowfall to precipitation ratios for the season and each winter month as a function of elevation and location -- very interesting data and plots, too much to present here now.) I suspect that cooling ocean temperature in the North Pacific throughout the winter contributes to this effect, along with a reduced likelihood of Pineapple Express systems in March and later. The average seasonal snowpack maximum is around April 1 for those sites (4000+ ft WA Cascades, 5000+ ft  OR Cascades, 6000+ ft CA Cascades), even trending as late as mid-April for some higher sites and more northerly sites.

Not sure what to think about Harts Pass and other east side locations, that is interesting that early-season correlations appear to be stronger. I've spent much less time studying snowpack trends at those sites, even compared to places like southern OR and northern CA, since I personally tend to ski on the east side much less often than I do anywhere along the volcanic crest of the range all the way south to California.

What type of skis work best when skiing in graphs?

I looked around for raw data concerning basin-wide SWE measurements but none is available in an easy-to-use format. This data archive may have the raw data in there as it is used to assemble some of the NSIDC products but frankly I'm not ambitious enough to wade through it myself:
ftp://sidads.colorado.edu/DATASETS/NOAA/G02158/

While poking around I did find some fun products though that I was not previously aware of. I think a lot of folks will get a kick out of this:
www.nohrsc.noaa.gov/nsa/js_animate.html?...thwest&ts=24&large=1


I wish that was in .GIF from so I could just have it display on this page! It is SNOTEL data combined with remote sensing via airplane flyovers to recreate basin-wide snow depth analysis, then animated for your viewing pleasure. If you go to the parent site you can see other years or other basins.  Visualization of the La Nina year of 2007-2008 is fun and so is the 2008-2009 lowland snow storms.
www.nohrsc.noaa.gov/nsa/index.html?regio...nth=6&day=19&units=e

Addressing a comment Amar made and that a lot of other people notice I'm sure: with the exception that it is a pass which makes it climatologically unique, Snoqualmie pass is beginning to, and likely will slowly continue to, transition from the kinds of conditions that make snow a sure-thing with most winter systems to an area that only gets snow during favorable conditions. This is the difference between alpine and lowland systems around here, and that SNOTEL site is right at the transition elevation at this point and is very sensitive to minor fluctuations in temperature. It will be a fascinating site to watch in the decades to come because taken at face value it looks like Snoqualmie ski area could suffer the same fate as poor Mt. Pilchuck, but then it has cold eastern flow that protects what snow it does get.  As a very brief summary, back when I was investigating SNOTEL data a lot more seriously the trends and research suggested that as our climate slowly begins to warm the trend will be towards a slowly rising regional snow line, but that is hydrologically balanced by an increase in percipitation (more snow at higher areas).  The correlations were weak and my understanding is dated though, so take that statement with a grain of salt.

Finally, I'm curious Amar, do you work with this data professionally/academically or do you just have a keen personal interest? Most folks don't know of or throw out acronyms like ENSO, SST, and PDO

What type of skis work best when skiing in graphs?

I'd bring my fatties for a couple feet of fresh data.

What type of skis work best when skiing in graphs?

rax skis due to the tight quarters.
b

Amar's post made me want to make some graphs to take a look at the trend visually.

Very cool. I'm still thinking about how to best interpret your correlation plots. One thing I might suggest: set the red/green scale to span [-1,1]. The location of black as off-zero understates the apparent correlation. Do your tools permit an on-the-fly generation of a significance measure to go along with the plot? Which software are you using?

(Also, for the color-blind, there may be a superior color palette choice. I haven't thought about it in the context of this sort of plot).

Thanks for bringing more data analysis to the party .

bscott,

You wouldn't by chance actually be a meteorologist?

You aren't suggesting that the pattern shown by n-1 and n won't result in n+1?

Shocking......

You may forget that color graphs tell the truth.

[/size]

Is that really what the climate modelers are saying? Not really, or at least that's a severe exaggeration of what most (scientifically peer-reviewed, published, etc.) climate modelers are saying. But I suspect you know that already, and are just being hyperbolic and alarmist (although some degree of alarm over anthropogenic climate change is probably warranted).

I disagree with Amar’s comment that I have exaggerated what climate modelers are currently saying.
A recent publication (scientifically peer reviewed) in Nature (October, 2013, 502, 183–187) attempts to clarify what the climate modelers are indeed saying.  The article frames the climate change discussion in a manner more easily understood by the uninformed public.  If carbon emissions remain at their current levels, the authors point out that climate models predict that large regions around the world will soon see temperature increases that have no recorded historical precedent.  By 2047, more than half of the planet will experience average temperatures hotter than anything seen between 1860 and 2005.  That is only 34 years!  Seattle is one of the cities impacted.  Eventually (shortly after 2047), the coldest year in Seattle is predicted to be hotter than the hottest year ever recorded in the last 150 years (1860-2005).  If the models are correct, within the next 30 years, the climate change signal should quickly overwhelm the natural variability signal in our weather data.

The point I wanted to make is that our climate is changing, and fairly rapidly.  What has seemed usual in the past may not be what we can expect in the future.  Past performance does not guarantee future results.  While I agree with Amar that the signal from climate change is still too small to detect in the current weather patterns, it is, never-the-less there.  That signal should be increasingly more apparent in the coming years. I believe that within a few years we will begin to notice a very different regime of temperature and snowfall in the Cascades.  That change could already be happening.

I disagree with Amar’s comment that I have exaggerated what climate modelers are currently saying.
A recent publication (scientifically peer reviewed) in Nature (October, 2013, 502, 183–187) attempts to clarify what the climate modelers are indeed saying.
. . .

The point I wanted to make is that our climate is changing, and fairly rapidly.  What has seemed usual in the past may not be what we can expect in the future.  Past performance does not guarantee future results.  While I agree with Amar that the signal from climate change is still too small to detect in the current weather patterns, it is, never-the-less there.  That signal should be increasingly more apparent in the coming years. I believe that within a few years we will begin to notice a very different regime of temperature and snowfall in the Cascades.  That change could already be happening.

Link to that Nature article (not free without institutional access): www.nature.com/nature/journal/v502/n7470/full/nature12540.html

OK, I appreciate the explanation of your point of view on this issue. Perhaps I am hoping that point of view turns out to be an exaggeration of the actual degree of climate change which occurs over the rest of my lifetime, at least.

Actually, I do agree with your statement that "within a few years we will begin to notice a very different regime of temperature and snowfall in the Cascades", or at least fear that it will come true -- but not primarily due to climate change within the next 2 decades, but rather due to the Pacific Decadal Oscillaton shifting back towards its warm phase instead of the current cold phase we are in.

Which would mean a likely return to the bad old years of the late 1970s, 1980s, and early 1990s, when even the best years were barely above average, and most years were mediocre to well-below average (although even those years produced snowpacks far beyond any others in the lower 48 outside the Sierra). I was fortunate to start backcountry skiing in the Northwest during the summer before 1996-97, which turned out to be the first huge snow year in over 2 decades, and then enjoyed a number of huge to record-type years since then (1998-99, 2001-2, 2005-6, 2007-8, 2010-11, 2011-12), with only 2 far-below-normal years (2000-1 and 2004-5). A return even to the snowpack regime of the late 1970s to early 1990s period would be a major ongoing disappointment compared to recent years.

Finally, I'm curious Amar, do you work with this data professionally/academically or do you just have a keen personal interest? Most folks don't know of or throw out acronyms like ENSO, SST, and PDO

No professional or academic involvement in meteorology or atmospheric sciences, although self-taught over a decade ago to maybe an advanced undergrad or beginning grad-student level in that field (or at least the areas of it which interest me). I'm an experimental physicist by training and spent a number of years as research faculty at UW in that field, although as many of you know I'm taking a lengthy career break to ski mountaineer full-time and attempt to complete my Cascade volcanoes ski guidebook. Perhaps ironically given my frequent posts of snow-related data, I never liked data analysis that much, and preferred instead to spend as much lab time as possible designing, machining, and building various experiments, apparatus, ultra-high vacuum systems, diode-laser systems, etc.

(Also, for the color-blind, there may be a superior color palette choice. I haven't thought about it in the context of this sort of plot).

The choice of using red and green in any plot definitely makes it hard for many of us to see it, I'm only minimally red-green color blind (the problem is worse for me when the red-green area is small, subtending a tiny angle in my field of vision) but always tend to notice that issue. Even the first plot of data points and lines is hard to see for me, trying to tell the red and green points apart with no other clue like differing data point markers for each site. But it's always hard to get those with normal color vision to use only red-green color-blind-safe colors when things look "fine" to them.

Below is a quote from the Forcast Discussion from NWS Seattle today.

.CLIMATE...THERE IS A CHANCE THAT THE REMAINDER OF THE MONTH WILL BE
DRY. THE PRECIPITATION TOTAL AT SEATTLE-TACOMA AIRPORT SO FAR FOR
THE MONTH OF DECEMBER IS 1.62 INCHES. THIS WOULD BE THE SECOND
DRIEST DECEMBER ON RECORD AT THE AIRPORT SURPASSED ONLY BY THE
RECORD 1.37 INCHES SET IN 1978. INCLUDING THE FEDERAL BUILDING
RECORDS WHICH GO BACK TO 1891 THIS WOULD BE THE FIFTH DRIEST
DECEMBER.

IT IS INTERESTING TO NOTE THAT THE RECORD WET SEPTEMBER WE HAD THIS
YEAR...6.17 INCHES...BROKE THE OLD SEPTEMBER RECORD SET IN 1978.
FELTON

Interesting.

Recent less scientific research has shown the snowpack to SUCK....

Uller,.... a little help please??

tragically, no one knows whether it will snow or not.