WSDOT - Only 80" of Snow at Snoq Pass this Winter

The last row of data in this table is depressing.

www.wsdot.com/winter/files/HistoricalSno...a1415season.pdf?v=11

Holy hell... 828 inches in '55-'56.

Interesting to see the yearly average steadily drop.

Wow, ~18% of average and nearly 10 feet less than the former lowest snow year.

Actually 1976-77 only reported 79" though February. The total of 80" this year only includes snowfall through February so comparing this year to the the "season snowfall" for past years may not be accurate.

It'll be interesting to see what we end up with though May, it's snowing this morning.

Some serious 37deg nukage going on up there! 76-77 picked up 112" in March, somehow I doubt we are hitting that this month...

I'm usually a pretty optimistic guy, but I've given up on a season saving (Snoqualmie Pass elevation) storm system to blow in. I'd take the under on 100" this season.

It is interesting to see the steady decline at this particular location.

Looking at rolling 3,4,& 5 year averages trend for a set of Hyak data going back to 1930, this current decade is still better than 1939-49 when every year was below average.
That said, his winter is shaping up to be a mirror of the big winter of 55/56, setting a record for the lowest snowfall.
Is this the ratchet effect, or a  long term trend?  We won't know for a few more winters.

i got time to wait this one out. now silas, he's just doing his same old thing but with different chicks probably.

Interesting to see the yearly average steadily drop.

It is interesting to see the steady decline at this particular location.

Come on folks, it's well known by now that this is a completely artificial effect, which occurs because that set of data is cut-off at 1950. So it accidentally starts with a bunch of huge snowfall years during the fattest part of the Pacific Decadal Oscillation (PDO) cycle, and leaves out a bunch of terrible low-snowfall years right before 1950. Extending the data set back as far as it exists makes this artificial effect vanish. Here is a plot of all available snowfall data at Snoqualmie Pass back to 1910, with several running averages superimposed:



Clearly the full cumulative average (red line) shows no such steady decline! It trends downward throughout the 1920s, increases a bit in the 1930s, decreases sharply again in the 1940s, then increases over the next 25 years through the mid 1970s, then decreases again until the mid 1990s, and finally holds almost steady for the last 2 decades, with increases in big years offset by decreases in other years (the cumulative average is 417" as of 1996 and still 417" after 2014).

The other long-term running averages over 10 and 30 year periods also show no such decline. If you look at the average snowfall in each calendar decade, it is also clear that no steady decline has occurred:

1910-1920 450"
1920-1930 356"
1930-1940 419"
1940-1950 343"
1950-1960 545"
1960-1970 474"
1970-1980 428"
1980-1990 361"
1990-2000 388"
2000-2010 387"


Regarding the 10 missing years that are not shown in the plot: most of those years are missing only 1 or 2 months of data during the crucial November-April period when about 98% of the annual snowfall at this location occurs. However, it seems best not to include such years in order to avoid skewing the averages. Of the 10 years not shown on the graph, 4 of them are actually really bad snow years, even assuming normal or heavy snowfall during the 1-2 missing months (1914-15, 1925-26, 1944-45, and 1945-46), while only 2 are near-normal (1911-12 and 1916-17) and the other 4 of them are missing most of the data for the entire season (1909-10, 1919-20, 1928-29, 1929-30). Therefore including the 6 near-complete years would only further reinforce what the plot already shows, that snowfall was far less than the long-term average during the 1920s and 1940s.

The older Snoqualmie Pass data is available from the Western Regional Climate Center at www.wrcc.dri.edu/cgi-bin/cliMONtsnf.pl?wa7781. There are slight discrepancies from the WSDOT data during the period that they overlap, but in general it's a pretty good match within a few %, as good as can be expected in such snowfall data. Note that the listed annual totals in the original WRCC data have a major flaw: when any month is missing more than 5 days, they don't count it at all in annual totals, which undercounts the totals severely in many years. Although it is proper to leave out partial months when calculating monthly averages, it is erroneous to leave out partial months in sums such as annual totals for cumulative quantities like snowfall or precip, since leaving those out makes the listed annual totals more wrong than including them does. I'm not sure how WRCC could make such a significant mathematical blunder in all of their data for all sites, but it's been like that for as long as I've been looking at the WRCC data (over 10 years).

So my listed annual totals do include such partial months, although if too much is missing in any year especially in the important big-snowfall months, I leave the annual total blank as mentioned above. But I have not yet gone through the original daily snowfall records for Snoqualmie Pass from the National Climatic Data Center in order to manually clean up any other errors that might be found in the older data (I usually do this at some point for most sites that I track snowfall data for, but it's a big pain).

For those who wish to see the complete Snoqualmie Pass data set, for pure interest and also to verify that no chicanery or manipulation occurred in the graph above, here it is as a screen capture from my original spreadsheet (I'd prefer not to post the original Excel spreadsheet online):




Note that all of this data (WSDOT and WRCC and TomK's data shown in a previous post) is from the summit of Snoqualmie Pass near 3000 ft (3010 or 3020 ft), none of it is from Hyak (2600 ft) despite what various files online may say. The confusion may arise because WSDOT has a maintenance / operations center at Hyak. However, snowfall at Hyak would be far less than at Snoqualmie Pass and the numbers in the data. Given the sharp decline in snowfall in that region both with decreasing elevation and increasing distance east of the Cascade Crest, although Hyak is only 2.5 miles east of the Crest, at 2600 ft it's likely to have at least 20-30% less snowfall than Snoqualmie Pass.


So what about the snowfall this year: obviously a freakish anomaly of the highest order, especially so at Snoqualmie Pass. With 1" of new snowfall recorded today (the first snowfall there in the entire month of March!?!), the total now stands at 81". How likely is significant additional snowfall? Current forecasts for the next week pretty much rule out additional snowfall this month at Snoqualmie, although heavy precip is certain for tomorrow, along with significant snowfall at higher elevations, and there may be a couple more systems on Friday and Monday which bring snow higher up. So on to April and May:

Average snowfall at Snoqualmie Pass in April and May is about 30" as shown in the data, but median snowfall is only 20" with a standard deviation of almost 30". The maximum April-May snowfall is 97" (in April 1955, followed by 0" that May), while the minimum April-May snowfall is 0" in several years. Which is to say, spring snowfall at Snoqualmie Pass is extremely fickle and variable, and quite likely to end up under 20". Since the median is 20", statistically there is only about a 50% chance of Snoqualmie breaking 100" this season. Given the lack of any indication from climate models of a cooler and wetter than normal April this year, the real chance is probably well under 50% at this point. And the likelihood of this year matching the previous record low of 172" is minuscule, statistically on the order of 1%, and realistically well under that.

Assuming it does end up under 100", how unusual, how statistically unlikely would such a total be? The previous record low in a complete season was 172" in 1941-42, trailed closely by 196" in 1940-41 and 191" in 1976-77. So a sub-100" snowfall would be a very extreme outlier at roughly half the previous low. Given the median snowfall of 413" over the full period of record with a standard deviation of 130", a total of 90" would be about 2.5 standard deviations below the median, which is in the 0.6 percentile, or roughly 1 in 160 years!!

That's all based on a normal distribution though, and annual snowfall totals are not "normally" distributed, but it's good enough for a rough approximation of how unlikely a sub-100" snowfall total would be. To verify that, let's see how many years fall under 220", which is 1.5 standard deviations below the median, or 6.7 percentile, roughly 1 in 15 years. Out of the 95 complete years, 6 of them are under 220", which matches the statistical expectation well. So this calculation method seems reasonable despite the snowfall totals not being normally distributed. And given that there are nearly 100 years of data, it's quite reasonable to encounter a 1 in 160 year event in such a data set.

Hmm... internet trolling really does work! I thought for sure you'd merely point back to your old thread of epic analytics in order to set straight a dumb statement about statistical snowfall.

Is teasing allowed here?  ;D

Anyway... mostly relevant to the above delving: Cliff Mass: Why has the weather been so unusual the past two winters?

Unfortunately the blob has taken a liking to the west coast. Thing needs to be convinced Detroit or somewhere else is just as nice...

Amar,

So what has been the overall trend of snow since 1950 at Snoqualmie Pass?

I understand you want to take every year's worth of data. Understandable. You are also taking a set data limit based on the information available. What about what happened in the 1700's and 1800's. What if the periods in the 1940-1970's were anomolies compared to the long term trends in the 1700's and 1800's? We don't know that information. Not trying to start a flame war here, but I know very little about statistics.

My only question is, what has been the overall trend of snow since 1950 at Snoqualmie Pass. I think it is fairly narrow question. And yes it is a limited question. Does it answer all the questions? No. It my opinion, it would answer a short term question for snow at Snoqualmie Pass. In my opinion it would not answer a long term question for snow at Snoqualmie Pass.

I hear the skiing at Snoqualmie was just sick during the Pleistocene Epoch.

So what has been the overall trend of snow since 1950 at Snoqualmie Pass?

I understand you want to take every year's worth of data.  Understandable.  You are also taking a set data limit based on the information available.  What about what happened in the 1700's and 1800's.  What if the periods in the 1940-1970's were anomolies compared to the long term trends in the 1700's and 1800's?  We don't know that information.  Not trying to start a flame war here, but I know very little about statistics.

My only question is, what has been the overall trend of snow since 1950 at Snoqualmie Pass.  I think it is fairly narrow question.  And yes it is a limited question.  Does it answer all the questions?  No.  It my opinion, it would answer a short term question for snow at Snoqualmie Pass.  In my opinion it would not answer a long term question for snow at Snoqualmie Pass.

The key issue is that your question is simply not a well-posed question for snow climatology in the Pacific Northwest: although it has an obvious answer, that answer is deceptive due to an inappropriate choice of starting point. It obscures the real trends, the real answers and insight into the behavior of the data that one is actually seeking. Because 1950 is the start of a period which is such an extreme positive relative to the overall longer-term averages, it just can't be the starting point for any fair and balanced snow climatology study in the Pacific Northwest, assuming one is actually looking for real answers, and not just trying to deceive oneself or the public and maybe push some sort of agenda (as several notoriously flawed studies have done).

Regarding statistics: Any cumulative average of any time-series data set which is cut off so that it starts with several values well-above the overall average will automatically have a downward trend, but that downward trend actually contains little or no useful information, since it primarily reflects the arbitrary choice of starting point. Cumulative averages are therefore always severely flawed because of this over-sensitivity to starting point. They really perhaps shouldn't be used at all, but it's a standard practice to calculate them.

Much better are running averages (such as the 5, 10, and 30 year averages shown on my plot above), which avoid that starting point issue, although they still have other artifacts. The cumulative average has been entirely downward for the data set cut-off to start in 1950 (showing a "steady decline"), but the running averages show that this has not been so at all, and reveal that snowfall in the past 2 decades has actually increased substantially over the previous 2 decades.

Fitted linear trend lines also have a similar false-impression issue to the cumulative average, although they do at least consider the entire data set at once unlike the cumulative average. When they start with several values well-above the overall average, they tend to artificially make things look like a "steady decline" when in fact the reality may be much more complicated, with substantial increases over various periods.

Overall, it's just far better to try to pick a "fair" starting point which better reflects the entire available data set. It is intuitively obvious by glancing at the Snoqualmie data (or the data for any other mountain site in the Pacific Northwest which extends back well past 1950) that 1910 or 1920 or 1930 are all MUCH better choices for a starting point than 1950. All the stuff about 1700s or 1800s is irrelevant, as no weather records exist in this part of the world. Although numerous studies have been done that far back and even farther, using various proxies for weather data such as dendrochronology (tree ring analysis), that's not even close to the same thing as actual real data. Since we do have good snowfall and snowpack data which extends back for about 100 years at a number of sites, we should use the entire data sets and not arbitrarily cut off at 1950 or any other year, with the caveat that if data quality is known to be worse prior to some date, then that could also set a reasonable starting point.

I hear the skiing at Snoqualmie was just sick during the Pleistocene Epoch.

Did you ask Silas how it was??

That's all based on a normal distribution though, and annual snowfall totals are not "normally" distributed, but it's good enough for a rough approximation of how unlikely a sub-100" snowfall total would be.

So if annual snowfall doesn't fit a normal distribution (which I imagine has something to do with extreme high and low events not having the same probabilities, as well as low events being limited by 0, and high events technically not limited), what type of fit is more appropriate?

In the end, it probably doesn't matter much anyway. After busting out my old hydrology text books and doing some quick napkin math with other distributions, this year would be anywhere from a 1 in 150 year event, to a 1 in 170ish year event. So, we won't have another year this bad for 150+ years, right?!  ;D

So if annual snowfall doesn't fit a normal distribution (which I imagine has something to do with extreme high and low events not having the same probabilities, as well as low events being limited by 0, and high events technically not limited), what type of fit is more appropriate?

Yeah, those are the main issues with the distribution deviating from normal.

It's actually not that bad to assume a normal distribution for annual snowfall at high-snowfall sites which are always reliably far above zero in every year (including Snoqualmie Pass, even this year!). It's also reasonably valid for April 1 snowdepth at most high-snowfall sites, as long as the snowdepth is always reliably far above zero in every year (not really the case at Snoqualmie Pass in any number of bad years). I don't know of any other distribution which fits better, and the calculational advantages of assuming a normal distribution are significant, while the flaws are unimportant for this type of rough calculation.

However, as annual snowfall decreases and variability increases, the normal distribution quickly becomes useless. One easy and instructive way to see this is to look at histograms of the annual snowfall versus histograms of the snowfall in a given month. Here it is for Snoqualmie Pass for annual, January, March, and April snowfall:



So the annual snowfall is a reasonable match to a normal distribution, as much as one could expect in this type of data. But January, the highest snowfall month there (average snowfall 97", median 88", standard deviation 55"), is showing a significant departure from normal as it runs too close to zero in a number of years and has a larger-than-expected number of high outliers, although it still has the basic normal shape.

Not so for March (average snowfall 67", median 60", standard deviation 42") or April (average snowfall 25", median 19", standard deviation 22"), which both clearly look nothing like a normal distribution. March is affected by very large scatter (manifesting itself as 2 peaks) and running close to zero in several years, while April is pretty much quashed up against zero in a large fraction of the years.

Gamma distribution!

Is the data making you a better skier?

One of the latest peer reviewed articles I could find on this subject, written by the most outspoken critics of the earlier "1950 - present" analysis by Mote et al (that Amar also heavily criticizes):

Mark T. Stoelinga, Mark D. Albright, and Clifford F. Mass, 2010: A New Look at Snowpack Trends in the Cascade Mountains. J. Climate, 23, 2473–2491.

journals.ametsoc.org/doi/abs/10.1175/2009JCLI2911.1

The abstract from the paper is quoted below.  The full paper is also pretty decent if you want to dive deeper.  The most interesting thing to me in this paper is that they removed the effect of Pacific variability and found that snowpacks have been declining about 2% / decade since 1930.  To my mind, this is the central question in whether our snowpack has been declining long term, much more so then looking at any particular year.

This study examines the changes in Cascade Mountain spring snowpack since 1930. Three new time series facilitate this analysis: a water-balance estimate of Cascade snowpack from 1930 to 2007 that extends the observational record 20 years earlier than standard snowpack measurements; a radiosonde-based time series of lower-tropospheric temperature during onshore flow, to which Cascade snowpack is well correlated; and a new index of the North Pacific sea level pressure pattern that encapsulates modes of variability to which Cascade spring snowpack is particularly sensitive.

Cascade spring snowpack declined 23% during 1930–2007. This loss is nearly statistically significant at the 5% level. The snowpack increased 19% during the recent period of most rapid global warming (1976–2007), though this change is not statistically significant because of large annual variability. From 1950 to 1997, a large and statistically significant decline of 48% occurred. However, 80% of this decline is connected to changes in the circulation patterns over the North Pacific Ocean that vary naturally on annual to interdecadal time scales. The residual time series of Cascade snowpack after Pacific variability is removed displays a relatively steady loss rate of 2.0% decade−1, yielding a loss of 16% from 1930 to 2007. This loss is very nearly statistically significant and includes the possible impacts of anthropogenic global warming.

The dates of maximum snowpack and 90% melt out have shifted 5 days earlier since 1930. Both shifts are statistically insignificant. A new estimate of the sensitivity of Cascade spring snowpack to temperature of −11% per °C, when combined with climate model projections of 850-hPa temperatures offshore of the Pacific Northwest, yields a projected 9% loss of Cascade spring snowpack due to anthropogenic global warming between 1985 and 2025.

I have been keeping snow totals for the pass for many years and I found many inaccuracies with the DOT during this time. I would post the totals every snowfall and compare with the ski resort, DOT and my own findings. I find the DOT numerous times was way off, showing more then what actually fell. Especially on the days of freezing rain where no snow falls the DOT page would report sometimes 8-12" of snowfall. Early years our totals were fairly close with end of season totals sometimes within 10" or so, but starting in 2008/09 that all changed. Since then the DOT records snow depths far above what I show, 50-100" of difference. This made me think they might get snow removal funding based on the amount of snow and they might beef up the numbers?
All I know is something changed in 2008 for their snowfall recording and now lack of accuracy.

Another snow measuring question - NWAC shows 23" at the base of Alpental (3100') and 14" at Hurricane Ridge (5250'). Webcams for both show completely bare ground, so where are the NWAC stations getting these measurements?

Since I'm sitting at home looking at the computer, I'm just curious. If I had driven somewhere expecting 2' of snow on the ground and it was dirt, I might be pissed.

Gamma distribution!

nerd

I have been keeping snow totals for the pass for many years and I found many inaccuracies with the DOT during this time. I would post the totals every snowfall and compare with the ski resort, DOT and my own findings. I find the DOT numerous times was way off, showing more then what actually fell. Especially on the days of freezing rain where no snow falls the DOT page would report sometimes 8-12" of snowfall. Early years our totals were fairly close with end of season totals sometimes within 10" or so, but starting in 2008/09 that all changed. Since then the DOT records snow depths far above what I show, 50-100" of difference. This made me think they might get snow removal funding based on the amount of snow and they might beef up the numbers?
All I know is something changed in 2008 for their snowfall recording and now lack of accuracy.

And therein lies the problem with analyzing and drawing conclusions from long term data sets for which meta-data or changes in data collection methods are not noted.

Not directly related to Snoqualmie Pass, but my favorite benchmark to judge the decline of the Cascade snowpack is to look at the glaciers.

Statistics may lie, but glaciers don't.

Another snow measuring question - NWAC shows 23" at the base of Alpental (3100') and 14" at Hurricane Ridge (5250').  Webcams for both show completely bare ground, so where are the NWAC stations getting these measurements?

Many of the stations are located in sheltered sites on generally flat ground. These locations improve accuracy of snowfall/precipitation measurements, though they often hold snow a bit longer than exposed sites. The Alpental station is located behind the main lodge. If the site hasn't been recently maintained then we may be seeing interference from brush

Many of the stations are located in sheltered sites on generally flat ground. These locations improve accuracy of snowfall/precipitation measurements, though they often hold snow a bit longer than exposed sites. The Alpental station is located behind the main lodge. If the site hasn't been recently maintained then we may be seeing interference from brush

Thanks!

...

So what about the snowfall this year: obviously a freakish anomaly of the highest order, especially so at Snoqualmie Pass. With 1" of new snowfall recorded today (the first snowfall there in the entire month of March!?!), the total now stands at 81". How likely is significant additional snowfall? Current forecasts for the next week pretty much rule out additional snowfall this month at Snoqualmie, although heavy precip is certain for tomorrow, along with significant snowfall at higher elevations, and there may be a couple more systems on Friday and Monday which bring snow higher up. So on to April and May:

Average snowfall at Snoqualmie Pass in April and May is about 30" as shown in the data, but median snowfall is only 20" with a standard deviation of almost 30". The maximum April-May snowfall is 97" (in April 1955, followed by 0" that May), while the minimum April-May snowfall is 0" in several years. Which is to say, spring snowfall at Snoqualmie Pass is extremely fickle and variable, and quite likely to end up under 20". Since the median is 20", statistically there is only about a 50% chance of Snoqualmie breaking 100" this season. Given the lack of any indication from climate models of a cooler and wetter than normal April this year, the real chance is probably well under 50% at this point. And the likelihood of this year matching the previous record low of 172" is minuscule, statistically on the order of 1%, and realistically well under that.

Assuming it does end up under 100", how unusual, how statistically unlikely would such a total be? The previous record low in a complete season was 172" in 1941-42, trailed closely by 196" in 1940-41 and 191" in 1976-77. So a sub-100" snowfall would be a very extreme outlier at roughly half the previous low. Given the median snowfall of 413" over the full period of record with a standard deviation of 130", a total of 90" would be about 2.5 standard deviations below the median, which is in the 0.6 percentile, or roughly 1 in 160 years!!

That's all based on a normal distribution though, and annual snowfall totals are not "normally" distributed, but it's good enough for a rough approximation of how unlikely a sub-100" snowfall total would be. To verify that, let's see how many years fall under 220", which is 1.5 standard deviations below the median, or 6.7 percentile, roughly 1 in 15 years. Out of the 95 complete years, 6 of them are under 220", which matches the statistical expectation well. So this calculation method seems reasonable despite the snowfall totals not being normally distributed. And given that there are nearly 100 years of data, it's quite reasonable to encounter a 1 in 160 year event in such a data set.

So maybe statistics are pretty useful for this sort of thing?! The roughly 50% statistical chance of breaking 100" did in fact come true, despite all meteorological indications to the contrary. All it took was one strong convergence-zone snowstorm on the night of March 31 to April 1, with snowfall rates of 2-3" per hour for a few hours at its peak, and 15" new for the day. From www.wsdot.com/winter/snoqualmie/:



The current season total of 100" is still about 2.4 standard deviations below the median (413" over the full period of record with a standard deviation of 130"), which is in the 0.8 percentile, or roughly 1 in 120 years!

On a side note, it looks like Snoqualmie Pass will make it through this entire season with ZERO hours of avalanche-control closures:



Here's the recent daily snowfall from i90.atmos.washington.edu/roadview/avalanche/hyak.htm (note that it's not measured at Hyak, but at Snoqualmie Pass 3000 ft):

Snoqualmie Snowfall Report
Courtesy of WSDOT Hyak Operation Center

Date        New Snow   Snow Depth

---

Mon Apr 13    0 in       0 in
Sat Apr 11    0 in       0 in
Thu Apr 09    0 in       0 in
Wed Apr 08    0 in       0 in
Tue Apr 07    0 in       0 in
Mon Apr 06    0 in       0 in
Fri Apr 03    0 in       4 in
Thu Apr 02    1 in       9 in  <<< Reaches 100" for season!
Wed Apr 01   15 in      15 in
Tue Mar 31    0 in       0 in
Fri Mar 27    0 in       0 in
Wed Mar 25    3 in       3 in
Tue Mar 24    1 in       1 in  <<< First snowfall in March!
Mon Mar 23    0 in       0 in
Fri Mar 20    0 in       0 in
Thu Mar 19    0 in       0 in
Wed Mar 18    0 in       0 in
Tue Mar 17    0 in       0 in

---

Although the Puget Sound convergence zone was kind to Snoqualmie that time, this weekend it missed Snoqualmie entirely, staying farther north and dumping 16" new at Stevens Pass from midday on April 11 into April 12, with similar snowfall rates of 2-3" per hour at its peak. Snoqualmie got relatively little precip from the weekend storm, almost all of which fell as rain at pass level, with only trace amounts of snow.

And here's the NWAC telemetry at Snoqualmie and Alpental over the 2-day period of that March 31 to April 1 storm, saved for posterity:

Northwest Avalanche Center
Washington Department of Transportation
Snoqualmie Pass, Washington
3770' temp above Lake Keechelus snow shed

MM/DD  Hour  Temp  Temp  Temp    RH  Wind  Wind  Wind  Hour Total 24 Hr Total Press
         PST     F     F     F     %   Avg   Max   Dir Prec. Prec.  Snow  Snow    mb
             3760' 3770' 3010' 3010' 3760' 3760' 3760' 3010' 3010' 3010' 3010' 3010'

---

  3 31   500    35    34    36    94    21    37   262   .04   .04     0     0  1013
  3 31   600    33    32    35    93    24    47   250   .01   .05     0     1  1014
  3 31   700    32    31    35    96    15    28   247   .03   .08     0     0  1014
  3 31   800    31    31    33    96    12    20   246   .05   .13     0     0  1015
  3 31   900    30    31    33    95    18    27   250   .05   .18     0     0  1016
  3 31  1000    31    32    37    92    13    24   257     0   .18     0    -0  1016
  3 31  1100    31    33    35    93    10    15   250   .02    .2     0     0  1017
  3 31  1200    31    34    34    96     8    13   249   .09   .29     0     1  1017
  3 31  1300    32    34    37    94     6    14   256   .02   .31     0     0  1017
  3 31  1400    32    31    33    96    14    45 -7999   .04   .35     0     1  1018
  3 31  1500    31    30    32    97    14    23   280   .07   .42     0     1  1018
  3 31  1600    32    31    32    97    12    19   272   .04   .46     0     0  1018
  3 31  1700    31    31    32    97     9    18   249   .07   .53     0     0  1018
  3 31  1800    30    31    32    98     5    15   246   .09   .62     0     0  1018
  3 31  1900    29    30    31    98     8    19 -7999   .13   .75     2     4  1019
  3 31  2000    30    30    31    98     5    13 -7999   .16   .91     2     4  1019
  3 31  2100    30    30    32    98     7    16   309   .14  1.05     3  -165  1019
  3 31  2200    30    30    31    98     9    20   286   .15   1.2     5  -165  1020
  3 31  2300    29    30    31    98    11    18   270   .14  1.34     8     9  1020
   4 1     0    30    30    31    98     8    17 -7999   .11  1.45    10    13  1020
   4 1   100    30    29    31    98    15    24   253   .14  1.59    10    13  1020
   4 1   200    30    29    30    98    14    31   259   .11   1.7    10    14  1021
   4 1   300    29    29    31    98     9    15   257   .13  1.83    11    13  1021
   4 1   400    28    29    30    98    11    16   254   .14  1.97    10    14  1021

---

   4 1   500    29    29    30    98     7    16   252   .17   .17     0    14  1021
   4 1   600    28    29    30    98    11    21   254   .08   .25     0    15  1022
   4 1   700    29    29    32    97     7    12   253   .03   .28     0    14  1022
   4 1   800    30    30    33    95     8    11   256   .06   .34     0    14  1022
   4 1   900    30    33    36    86    10    17   250   .03   .37     0    13  1023
   4 1  1000    31    34    37    87    11    19   248     0   .37     0    12  1023
   4 1  1100    32    32    39    82     7    16   265     0   .37     0    13  1023
   4 1  1200    32    34    38    83     3     8 -7999     0   .37     0    10  1023
   4 1  1300    33    35    42    75     6    18   264     0   .37    -0     9  1022
   4 1  1400    32    35    45    70     8    13 -7999     0   .37     0     8  1022
   4 1  1500    33    35    39    82    12    22   249     0   .37     0     9  1022
   4 1  1600    32    32    36    92     8    17   270   .01   .38     0     9  1022
   4 1  1700    31    33    35    94     8    15   247   .03   .41     0    10  1022
   4 1  1800    31    31    35    93    10    18   255   .02   .43     0     9  1022
   4 1  1900    31    31    32    97    15    22   249   .01   .44     0     9  1023
   4 1  2000    31    30    32    97    12    19   250   .03   .47     0     9  1023
   4 1  2100    30    30    32    97    12    19   255   .02   .49     0     9  1023
   4 1  2200    29    30    31    98     8    15   244     0   .49     0     9  1024
   4 1  2300    30    29    31    98     9    15   258     0   .49     0     8  1024
   4 2     0    29    29    31    98     7    13   253     0   .49     0     9  1024
   4 2   100    29    29    32    98     9    13   246     0   .49     0     8  1024
   4 2   200    29    29    32    98     8    15   242     0   .49     0     8  1024
   4 2   300    29    30    32    98     7    11   243     0   .49     0     8  1024
   4 2   400    29    29    31    98     8    12   235     0   .49     0     8  1024

---

Northwest Avalanche Center
Alpental Ski Area, Washington
Wind gages unheated and may rime
5470' Intermittent snow out

MM/DD  Hour  Temp  Temp  Temp    RH    RH  Wind  Wind  Wind  Hour Total 24 Hr Total 24 Hr Total Inter
         PST     F     F     F     %     %   Avg   Max  Dir. Prec. Prec.  Snow  Snow  Snow  Snow  Snow
             5470' 4350' 3100' 3100' 5470' 5520' 5520' 5520' 3100' 3100' 3100' 3100' 4350' 4350' 5470'

---

  3 31   500    28    33    37    96   100    26    45   235   .03   .03     0    13     0    25    39
  3 31   600    26    32    36    97    99    20    37   235   .01   .04     0    13     0    24    37
  3 31   700    26    32    35    98   100    19    32   234   .02   .06     0    14     0    21    39
  3 31   800    27    31    33    99    99    14    24   234   .08   .14     0    14     1    21    39
  3 31   900    27    31    34    99    98    18    31   234   .05   .19     0    14     2    22    38
  3 31  1000    29    33    36    92    96    19    33   235   .01    .2     0    13     2   283    35
  3 31  1100    28    33    35    96    97    15    27   236   .01   .21     0    13     2   283    29
  3 31  1200    29    32    34    98    97    16    31   236   .09    .3     0    13     2   283    27
  3 31  1300    27    34    36    96    98    20    36   235   .02   .32     0    13     2    23    17
  3 31  1400    26    32    33    98    99    20    40   238   .05   .37     0    13     2    23   -27
  3 31  1500    26    32    33    99    99    16    26   234   .06   .43     0    12     4   283  -170
  3 31  1600    26    32    33    99    99    17    31   234   .04   .47     1    14     4    24  -224
  3 31  1700    26    31    33    99    98    11    21   237   .09   .56     1    12     5   283  -132
  3 31  1800    25    30    33    99    98    11    24   234   .12   .68     0    14     5    26   -74
  3 31  1900    24    29    32    99    98    11    14   241   .13   .81     0    17     7    28   -39
  3 31  2000    25    29    33   100    98     7    11   237   .15   .96     4    16     7    27   -18
  3 31  2100    24    29    32    99    98     9    21   234   .12  1.08     4    18     8    32    -6
  3 31  2200    24    29    33   100    99    11    16   235   .17  1.25     6    20    11   283     4
  3 31  2300    24    29    32   100    99    10    20   232   .14  1.39     8    26    14   283     9
   4 1     0    24    29    32   100    98    13    22   228   .12  1.51     8    29    16    39    10
   4 1   100    24    29    32   100    99    15    27   235   .16  1.67     8    28    17    41   -51
   4 1   200    24    28    32   100    99    16    28   234   .11  1.78     8    28    17   283   -31
   4 1   300    24    28    32   100    99    15    32   233   .13  1.91     8    21    17   283   -16
   4 1   400    23    28    31   100    98    14    26   234   .14  2.05     7    28    17   283    -6

---

   4 1   500    23    28    32    99    98    11    19   234   .14   .14     8    28    18   283     1
   4 1   600    24    28    31   100    98    11    28   234   .09   .23     0    28    18   283     7
   4 1   700    24    28    33    98    99    12    23   233   .06   .29     0    31    18    41    11
   4 1   800    26    29    33    95    99    10    20   234   .04   .33     0    33    18   283    13
   4 1   900    31    32    34    95    99    10    17   233   .02   .35     0    32    18   283    12
   4 1  1000    32    33    35    93    98     7    13   234   .02   .37     0    32     0    42     7
   4 1  1100    34    35    39    85    98    11    20   234   .02   .39    -0    59     0    41   -20
   4 1  1200    33    35    39    86    93     8    15   236   .01    .4    -0    66     0    36   -45
   4 1  1300    34    36    39    88    91    10    19   237     0    .4     0    72     0    38   -32
   4 1  1400    35    37    39    85    89    10    21   248   .01   .41     0    74     0    35   -26
   4 1  1500    30    36    39    89    94     8    15   254     0   .41     0    74     0    38   -78
   4 1  1600    28    34    35    94    97    11    20   250   .02   .43     0    75     0    36   -10
   4 1  1700    29    33    34    95    95    11    18   235   .02   .45     0    75     0   283     2
   4 1  1800    28    32    34    96    97    12    20   237   .03   .48     0    75     1   283     7
   4 1  1900    26    31    33    98    98    13    22   232   .04   .52     0    75     0   283   -80
   4 1  2000    26    31    33    98    99    14    26   247   .04   .56     0    75     2   283   -67
   4 1  2100    25    30    33    99    98    16    27   291   .02   .58     0    72     2   283   -29
   4 1  2200    24    29    32    99    97    16    28   345     0   .58     0    74     2   283   -13
   4 1  2300    23    28    32   100    99    18    26   345     0   .58     0    74     2    41    -8
   4 2     0    23    28    32    99    97    18    27   347     0   .58     0    74     2    42    -6
   4 2   100    24    28    32    99    98    12    20   348     0   .58     0    74     2    41    -4
   4 2   200    24    29    32    99    98     7    17   325     0   .58     0    74     2    41    -4
   4 2   300    24    29    32    99    98    12    23   345     0   .58     0    74     2    38    -4
   4 2   400    24    29    32    99    97     7    14   327     0   .58     0    74     2    38    -5

---

Not directly related to Snoqualmie Pass, but my favorite benchmark to judge the decline of the Cascade snowpack is to look at the glaciers.

Statistics may lie, but glaciers don't.

Glaciers may not lie, but they may instead be telling us something different than what we might initially assume.

Clearly glacial recession is proof of a significant decline in snowpack -- but snowpack on what date, and at what elevation? Glacier mass balance depends only on the snowpack remaining in the accumulation zone as of the end of summer, prior to start of the next season's snowfall. At elevations above 6500-8000 ft in the Cascades where the accumulation zones of all glaciers in the range sit, that date is sometime from about September to October in most years, and as late as November in rare years with extremely dry September-Octobers. Only the snowpack which exists in its accumulation zone matters to a glacier's health, while snowpack lower down on the glacier has almost no effect, and snowpack below or off the glacier none at all.

It is well known that glacial mass balance, and glacial recession or expansion, depend very strongly on summer temperatures and cloudiness. A very cool cloudy summer such as the one we had in 2010 following a fairly average snowpack season can result in significant positive mass balance. Much more so than other years like 2008 which by any measure was a huge snowpack year in the Northwest, especially so at low elevations, but with normal warm summer weather resulted in much less gains for the glaciers. An extended pattern of very cool and cloudy summers can result in significant glacial expansion, even with no increase in wintertime snowpack above average levels over that period, while a run of hot sunny dry summers will cause significant glacial recession even if the preceding winter snowpacks were all well above-normal.

So glacial mass balance and glacial recession really tell us nothing about the overall winter snowpack, or at most very little, and they tell us absolutely nothing about the low-elevation snowpack (roughly 1500-3500 ft in the WA Cascades) and even the mid-elevation snowpack (roughly 3500-5500 ft), which lie far below their accumulation zones. As we have seen so clearly during the 2014-15 season, the low-elevation snowpack (extremely below-normal this year) can be highly uncorrelated from the mid- and high-elevation snowpack (way closer to normal this year above 5000 ft), and that relative lack of correlation holds true in many other seasons too, albeit to a lesser degree than this freakish season.

In a typical year the Snoq area used to be a goto place. Easy to get to, no gate issues, lots of choices as long as the snowpack is deep in the low elevations. This year I did not make one trip there. I hate tearing up my ski bases. The prior year I also found myself avoiding Snoq.

What has been happening at Snoq is quite disconcerting. Even the prior season skiing was limited for Snoq in the opportunities for decent skiing. In recent years January has been pathetic. Sadly I do not see this situation getting any better.

This year was a disaster and sadly some of the prognostications for next year are not very good. It might be in a decade Snoq will essentially be unskiable for a good portion of the ski season.

If people are not seeing this shift they are not being honest the times they are a changin.

In a typical year the Snoq area used to be a goto place. Easy to get to, no gate issues, lots of choices as long as the snowpack is deep in the low elevations. This year I did not make one trip there. I hate tearing up my ski bases. The prior year I also found myself avoiding Snoq.

What has been happening at Snoq is quite disconcerting. Even the prior season skiing was limited for Snoq in the opportunities for decent skiing. In recent years January has been pathetic. Sadly I do not see this situation getting any better.

This year was a disaster and sadly some of the prognostications for next year are not very good. It might be in a decade Snoq will essentially be unskiable for a good portion of the ski season.

If people are not seeing this shift they are not being honest the times they are a changin.

In 2008 Snoqualmie had over 600" and both 2010 and 2011 they opened in November with average (aprox 400") seasons. 2005 was horrible and the past 2 were poor but it was worse from 1977-1981 and the 1940's were even worse then that. Just keep the glass half full, it will be back again.

Snoqualmie will be deep again soon. 'Till then, there's a huge playground out there. (Photo Thursday evening).