Jan 13, the Sierra/ Tahoe

I just checked Tahoe Daily and this morning it was -22 degrees,  The seasonal snowfall is 60% and the forecast is  a 2 week dry spell.

author=Zap link=topic=26979.msg113720#msg113720 date=1358117528]
I just checked Tahoe Daily and this morning it was -22 degrees,  The seasonal snowfall is 60% and the forecast is  a 2 week dry spell.

A) -22 degrees? are you working in celsius?

B) snowpack is well above 60%, http://www.tahoedailytribune.com/article/20130103/ARCHIVES01/130109982/1065/currentconditions&parentprofile=1065

author=komo link=topic=26979.msg113773#msg113773 date=1358184810">
A) -22 degrees? are you working in celsius?

B) snowpack is well above 60%, http://www.tahoedailytribune.com/article/20130103/ARCHIVES01/130109982/1065/currentconditions&parentprofile=1065

Zap was referring to The Tahoe Daily Snow (http://opensnow.com/dailysnow/tahoe, formerly at http://tahoeweatherdiscussion.com/), a very useful blog about upcoming and long-range weather conditions along the entire West Coast, with specific snowfall predictions for the Tahoe region.

See this post from Jan 13:

It was -22 degrees this morning at 6 a.m. at the Truckee Airport.  That is unofficially a record low.  We have a long way to go to warm up 45 degrees to the forecasted high of 23.

...

Luckily we have picked up 60% of the seasonal snowfall on the mountains less than 40% of the way through the season.

So apparently -22 Fahrenheit, not Celsius. And stating that roughly 60% of the average yearly snowfall (at Tahoe ski areas) has already fallen as of this date, not that snowpack is 60% of normal for this date.

However, it looks like Bryan (The Tahoe Daily Snow author) misread the dew point for the air temperature at Truckee Tahoe Airport, so the actual temperature was "only" -17 °F with a dew point of -22 °F around 6am. The lowest temperature on Jan 13 occurred a couple hours later near 8am, reaching -18 °F with a dew point of -24 °F.

See National Weather Service, Observed Weather for past 3 Days, Truckee-Tahoe (http://w1.weather.gov/obhistory/KTRK.html), this screen grab shows the lowest temps yesterday and today -- it's still below zero °F this morning!:



I couldn't find historical records for the airport, but the records for the nearby Truckee Ranger Station (about 2 miles NW of the airport and at similar elevation, about 5900 ft) show record lows down to -28 °F for some days in January, so it can definitely get below -20 °F at Truckee.

From http://www.wrcc.dri.edu/cgi-bin/cliMAIN.pl?ca9043:

Daily Records for station 049043  TRUCKEE RANGER STN         state: ca

For temperature and precipitation, multi-day accumulations
   are not considered either for records or averages.
The year given is the year of latest occurrence.

Period requested -- Begin :  1/ 1/1850 -- End :  9/30/2012
Period      used -- Begin :  9/ 1/1904 -- End : 12/18/2011

  Cooling degree threshold =   65.00  Heating degree threshold =   65.00

AVG   Multi-year unsmoothed average of the indicated quantity
HI    Highest value of indicated quantity for this day of year
LO    Lowest  value of indicated quantity for this day of year
YR    Latest year of occurrence of the extreme value
NO    Number of years with data for this day of year.
      Units: English (inches and degrees F)

     |---Maximum Temperature---|---Minimum Temperature---|----Precipitation---|-------Snowfall-----|------Snowdepth-----|--Heat--|--Cool--
MO DY AVG  NO  HI   YR  LO   YR AVG  NO  HI   YR  LO   YR   AVG  NO  HIGH   YR   AVG  NO  HIGH   YR   AVG  NO  HIGH   YR HDD   NO  CDD  NO
1  1  38  88  58 1918  18 1952  13  87  40 1997 -15 1919 0.137  87  2.01 1997  0.98  86  12.0 2005  17.1  68   70. 1952 39.8  87  0.0  87
1  2  37  86  60 1918  12 1952  13  86  40 1997 -14 1919 0.188  86  3.42 1997  1.22  86  16.0 2004  16.8  69   69. 1952 40.1  86  0.0  86
1  3  37  88  62 1915   8 1910  11  88  31 1914 -14 1919 0.169  85  4.50 1916  1.41  86  45.0 1916  17.2  68   69. 1952 40.9  88  0.0  88
1  4  38  88  55 2003  15 1910  13  88  33 2007 -17 1949 0.127  85  1.26 1987  1.23  85  21.0 1987  17.4  66   68. 1952 39.7  88  0.0  88
1  5  38  88  60 1911  12 1913  13  88  31 1986 -12 1972 0.209  86  3.95 2008  1.74  86  27.0 1982  18.2  66   58. 1982 39.8  88  0.0  88
1  6  37  89  56 2001  14 1913  13  89  40 1918  -9 1949 0.158  85  2.28 1959  1.54  85  21.0 1959  18.9  67   55. 1993 40.1  89  0.0  89
1  7  39  89  59 1969  10 1937  14  89  41 1918 -21 1937 0.147  86  2.15 1965  1.34  85  22.0 1965  18.8  66   60. 1993 38.9  89  0.0  89
1  8  40  88  58 2009   8 1937  14  88  34 1990 -26 1937 0.155  86  2.34 2005  1.39  85  16.0 2005  18.3  69   64. 1993 38.0  88  0.0  88
1  9  40  88  55 1983  22 1913  15  89  37 1911 -22 1937 0.188  86  2.05 1940  1.86  85  24.0 1911  18.6  69   65. 1993 37.9  88  0.0  88
1 10  41  89  58 1941  10 1913  16  90  33 1959  -9 1949 0.208  86  2.70 1916  1.56  86  27.0 1916  18.8  70   70. 1993 37.0  89  0.0  89
1 11  40  88  59 1986   8 1913  16  89  33 2000 -12 1909 0.184  86  1.63 1950  1.75  85  30.0 1950  19.2  70   70. 1993 37.3  88  0.0  88
1 12  39  88  58 1990  12 1910  15  88  34 1959 -15 1963 0.216  87  2.39 1980  2.07  85  30.0 1911  20.2  70   86. 1952 38.3  88  0.0  88
1 13  39  90  60 1996  15 1963  15  90  33 1980 -12 1917 0.214  87  1.90 1980  2.00  85  24.0 1911  20.0  70   86. 1952 38.5  90  0.0  90
1 14  40  90  57 1996  13 1997  17  90  38 1909 -15 1917 0.237  86  1.43 1980  1.97  86  18.0 1950  20.8  69   86. 1952 37.1  90  0.0  90
1 15  40  89  56 1996  15 1917  16  89  40 1909 -20 1917 0.216  86  1.97 1970  1.55  86  14.0 1979  21.9  83  118. 1911 37.4  89  0.0  89
1 16  39  89  55 1967  10 1917  16  89  42 1974 -21 1917 0.204  86  1.56 2000  1.53  85  16.0 1952  21.3  69  108. 1952 37.7  89  0.0  89
1 17  38  90  55 1959   8 1917  15  90  38 1909 -28 1917 0.339  87  3.60 1914  2.32  86  36.0 1914  21.8  71  100. 1952 38.5  90  0.0  90
1 18  40  89  58 1961  12 1910  15  89  40 1909 -22 1917 0.154  87  2.80 1914  1.41  86  28.0 1914  21.9  69   98. 1952 37.9  89  0.0  89
1 19  41  90  58 1986  14 1910  14  90  40 1909 -26 1913 0.185  86  1.94 1951  1.58  85  28.0 1951  22.4  68   95. 1952 37.7  90  0.0  90
1 20  39  90  58 1986  10 1913  14  90  36 1909 -25 1937 0.169  88  2.00 1969  1.56  85  17.0 1957  21.8  69   90. 1952 38.7  90  0.0  90
1 21  40  90  64 1950   8 1937  14  90  36 1950 -28 1937 0.261  88  3.22 1943  1.48  85  17.0 1964  22.8  69  100. 1952 38.6  90  0.0  90
1 22  39  90  57 1963  12 1962  15  90  39 1970 -18 1917 0.228  88  2.86 1967  1.80  85  28.0 1967  23.1  70   96. 1952 38.1  90  0.0  90
1 23  40  89  57 1981  17 1962  15  89  41 1910 -20 1962 0.187  86  2.88 1997  1.10  86  22.0 1997  22.5  68   90. 1952 37.6  89  0.0  89
1 24  40  90  55 1992  18 1909  15  90  39 1911 -20 1962 0.258  88  2.39 1910  2.01  86  24.0 1910  24.1  71   90. 1952 37.6  90  0.0  90
1 25  40  89  60 2007  15 1949  16  89  32 2000 -19 1949 0.275  88  2.80 1914  2.04  85  28.0 1914  24.5  68   86. 1952 37.2  89  0.0  89
1 26  40  89  57 2007  14 1913  17  89  38 1912  -6 1917 0.205  87  2.63 1969  1.44  86  15.0 1914  24.6  68   82. 1952 36.7  89  0.0  89
1 27  40  90  58 2003  14 1913  16  90  33 1967 -10 1957 0.252  87  2.39 1916  2.24  86  31.0 1937  25.2  70   80. 1952 37.5  90  0.0  90
1 28  39  90  56 1988   8 1913  14  90  33 1920  -8 1979 0.176  86  1.65 1981  1.95  86  18.0 1981  25.7  68   78. 1952 38.4  90  0.0  90
1 29  40  90  59 1976  15 1910  13  90  40 1911 -13 1979 0.080  87  2.16 1967  0.96  85  17.0 1981  25.1  68   78. 1952 38.7  90  0.0  90
1 30  40  89  60 1920  10 1910  13  89  34 1986 -16 1916 0.194  87  3.99 2011  1.56  86  20.0 1968  25.5  69   78. 1952 38.7  89  0.0  89
1 31  40  89  60 1920  18 1913  14  89  35 1995 -18 1917 0.153  85  2.61 1963  1.27  86  16.0 1939  25.8  81   84. 1916 38.6  89  0.0  89
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