Mount Rainier Paradise reaches 200" snow depth

Mid-June sounds like good spring skiing this year,and I'll go with you, too. ;D

Updated totals for the leading CA telemetry sites:
Mt Shasta, Old Ski Bowl (7600 ft) reached 209" last night, and has now settled by a few inches to 204".
Lassen Peak, Lake Helen (8250 ft) reached 241" last night, and has now settled by a few inches to 237", but remains just ahead of Baker Ski Area which has 233".
Meadow Lake CCSS site (7200 ft) appears to have reached 235" last night, although the data remains very flaky and intermittent.
Leavitt Lake SNOTEL (9600 ft) reached 225" this morning, and has now settled by a few inches to 221".

A couple of the Tahoe ski areas are now reporting summit snowdepths of over 300" (as always, some of the numbers are inconsistent from day-to-day, and no telemetry sites near the ski areas come close to matching these depths, except at Mammoth):
Sugar Bowl:  62-86" new the last 3 days, and still reports a 154-287" snowdepth (unchanged since yesterday).
Boreal:  83-90" new the last 3 days, and now reports a 175-300" snowdepth (it was only 100-200" yesterday ??).
Northstar:  42-52" new the last 3 days, with a 210" snowdepth at its summit.
Squaw Valley:  58-72" new the last 3 days, with a 250" upper snowdepth (yesterday was only 190" ??) and seasonal snowfall of 596" at 8200 ft according to their Snowfall Tracker 2010-11 .
Alpine Meadows:  73-101" new the last 3 days, and now reports a 175-308" snowdepth.
Sierra at Tahoe:  36-66" new the last 3 days, and still reports a 208" snowdepth at its summit (unchanged since yesterday).
Kirkwood:  75-90" new the last 2 days, and now reports a 203-247" snowdepth, with seasonal snowfall of 627-641" -- the changes since yesterday don't quite add-up, as usual.
Mammoth:  63-100" new the last 3 days, with a 15-22 ft (180-264") snowdepth and 530" of seasonal snowfall.
The Mammoth Ski Patrol's telemetry site at 9000 ft has 188", and the nearby Mammoth Pass USBR site (9300 ft) has 195" as of this morning.

Interesting that 4 out of the past 7 years at Mammoth have been over 500" and among the all time leaders (including the top 2 and likely the top 3 before this calms down):

patrol.mammothmountain.com/MMSA-SnowSummary70-Current.htm

The 2010-11 snow season continues to be fascinating, with periods of exceptional snowfall in both the Pacific Northwest and California over the last 6 weeks since mid-February. The just-concluded back-to-back-to-back huge California storm cycles (March 14-16, 17-22 and 23-27) brought 10-20 ft of snowfall to Shasta, Lassen, and the Sierra Nevada, but that appears to be the last of the heavy snowfall for California for at least the next 1-2 weeks as the storm track is shifting back into the Pacific Northwest over that period.

Updated totals for the leading telemetry sites, those which have exceeded 200" at some point this season:

The Upper Squamish River BCRFC site (4500 ft, west of Whistler and Mt Cayley) has settled to 213" as of March 25, well off its seasonal maximum of 239" on March 16 -- still the most of any Canadian telemetry site. Online data for all BCRFC telemetry sites appears to be down since March 25.

Mt Baker Ski Area (4200 ft) has 224" as of March 28 (about 130% of normal), well off its seasonal maximum of 253" on March 16. The ski area reports a base of 262" at 5000 ft atop Pan Dome, well off its seasonal maximum of 283" on March 17. The Mt Washington ski area on Vancouver Island reports 273" as of March 28 at their mid-mountain site (about 4500 ft), and has remained ahead of Baker throughout this season since late December, when it reported over 80" new in 3 days before Christmas, reaching a 205" snowdepth on December 25.

Brown Top SNOTEL (5830 ft, on the long ridge extending east from Mt Redoubt in the North Cascades) reached 202" on March 16-17, and now has 170" as of March 28 after continuing settlement with minimal additional snowfall since March 19.
Easy Pass SNOTEL (5270 ft, 8 miles east of Mt Shuksan) has no working snowdepth sensor, but its snow-water equivalent has held near 92" with minimal additional snowfall since March 19, implying a snowdepth of around 200-220" as of March 28.
Cayuse Pass SNOTEL (5240 ft, near the hairpin turn on SR 410 above Cayuse Pass) reached 202" on March 16, and now has 201" as of March 28 with continuing occasional snowfall offsetting the settlement.

And Paradise continues to hover near and just above/below 200" for the past 18 days since March 10, with continuing new snowfall slightly exceeding the ongoing settlement of the snowpack. Snowfall for the season-to-date is reported at 689" as of this morning March 28, already surpassing its average annual snowfall of 680" (the highest average of any measurement site in the world). The depth is 210" on the NPS snow stake (a new seasonal maximum and 120% of normal) with 203" on the NWAC telemetry as of March 28, just shy of the seasonal telemetry maximum of 204" on March 16.

Mt Hood, Timberline Lodge (6000 ft) is up to 179" as of March 28, its seasonal high and about 110% of normal, with seasonal snowfall of 560". No other telemetry sites in Oregon are over 160", although Mt Bachelor Ski Area is reporting a base of 170-195" (at 6300 and 7700 ft), with 543" of snowfall and 17" new today. Crater Lake park headquarters (6400 ft) has a seasonal high of 156" (about 130% of normal) as of March 28 with 542" of snowfall, already surpassing its average annual snowfall of 524".

Mt Shasta, Old Ski Bowl (7600 ft) reached 223" on March 24, and after settling by several inches, with renewed snowfall again reached 223" on March 26 and is now at 222" as of March 28 (about 180% of normal). The sensor is mounted much too low at this site at only 237" high, and many readings over the past few days have been this 237" value. If it resumes snowing heavily, the sensor may get buried like it did in 2006 when the snowdepth reached 284" (in a manual measurement on April 12), an all-time record for any site on Mt Shasta. (Yesterday's report from the Mt Shasta Avalanche Center staff assumes that the sensor is already buried and estimates the snowdepth at 245+" -- however, the data appears to indicate that the sensor may not quite be buried yet.)

Lassen Peak, Lake Helen (8250 ft) reached 274" on March 26 and now reads 269" as of March 28 (about 160% of normal). This is the most of any telemetry site in North America this season, but well below this location's record depth of 331" set on March 31, 1983 (a monthly manual snow course measurement, 20 years before the telemetry site was built). This site has two snowdepth sensors, the primary one mounted at 297" above ground and an auxiliary sensor (on another tower?) at 357" high -- the auxiliary sensor has been reading about 10" less than the primary one for the past few weeks, although mostly it's giving the 357" error value.

The Lassen Volcanic National Park visitor center (6700 ft) has a depth of 192" as of March 28. The visitor center has been closed since March 23 due to the heavy snowfall, and the webcam looking north out the window shows that the building has gotten nearly buried by snow:









The Meadow Lake CCSS site (7200 ft, north of I-80 and Lake Tahoe) appears to have reached 261" as of March 25 and showed 259" as of March 27, although the data remains very flaky and intermittent (most of the readings are 276", which is the height of the sensor above ground).

Independence Lake SNOTEL (8350 ft, 15 miles east of Meadow Lake CCSS site) reached 214" as of March 25, and has 196" as of March 28.
Stanislaus Meadow CCSS site (7750 ft, on Hwy 4, south of Lake Tahoe) reached 200" as of March 25, and has 186" as of March 28.
Leavitt Lake SNOTEL (9600 ft, west of Bridgeport, well south of Lake Tahoe) reached 237" as of March 25, and has 230" as of March 28.

The Mammoth Ski Patrol's telemetry site at 9000 ft reached 215" as of March 25, and has 199" as of March 28. The nearby Mammoth Pass USBR site (9300 ft) reached 195" as of March 21 and again on March 23, but the snowdepth sensor has been offline since then even as 3-4 ft of additional snow has fallen.


Several of the Tahoe ski areas plus Mammoth are reporting summit snowdepths of over 300" as of March 27, the end of the recent storm cycles (as always, some of the numbers are inconsistent from day-to-day, and no telemetry sites near the ski areas come close to matching these depths, except at Mammoth):

Sugar Bowl: snowdepth 178-303"
Boreal: snowdepth 275-375" ?!?
Northstar: snowdepth 132-231", season snowfall 404-634", and 109-166" new during the March 14-27 period.
Squaw Valley: snowdepth 95-265", season snowfall 441-689", which they say breaks their all-time record snowfall of 662", with 151-209" new during the March 14-27 period and 168-241" for the month of March.
Alpine Meadows: snowdepth 189-312", season snowfall 572-800" with a new record of 201" in March
Sierra at Tahoe: snowdepth 132-250", season snowfall 430-719", and 101-204" new during the March 14-27 period.
Kirkwood: snowdepth 229-273", season snowfall 691-713"

Interesting that 4 out of the past 7 years at Mammoth have been over 500" and among the all time leaders (including the top 2 and likely the top 3 before this calms down):

patrol.mammothmountain.com/MMSA-SnowSummary70-Current.htm

Mammoth has a snowdepth of 204-324", with season snowfall 606" and 151" new during the March 14-27 period, as reported by the ski area . Snowfall is 589" as reported on the Mammoth Ski Patrol's pages , with 148" new during the March 14-27 period.

Confusingly, Mammoth has two entirely different sets of long-term monthly snowfall stats, from the ski area (main lodge, 8900 ft) and the ski patrol (9000 ft snow study plot nearby). The numbers differ slightly (typically a few percent) but they are impossible to fully reconcile with each other (missing months in one set or the other, some months with large differences between the two sets, even though most are very close, etc). This year's 589" is a new record in the ski patrol stats, exceeding the 578" recorded in 2005-6, but the ski area recorded 668" that same year and widely reported that number as its all-time record snowfall.


[size=small](Edited to fix broken link.)[/size]

That visitor's center is not short. Whole lotta snow! Thanks Amar!

www.flickr.com/photos/76248783@N00/2932740999

Thanks, Amar.

Any thoughts about the climatology regarding the clustering of the heavy snow years recently at Mammoth?

I've noticed that heavy snow years are often grouped in six to seven year periods in the Paradise records. Wonder why?

The unusual and often spectacular 2010-2011 snow season continues delivering the goods into early April. Here are some more updated totals, as recent snowfall in WA and OR has brought most snow measurement sites to new seasonal maxima, and several more sites have reached the 200" mark:

BC:
The Upper Squamish River BCRFC site (4500 ft, west of Whistler and Mt Cayley) reached 226" as of April 6, below its seasonal maximum of 239" on March 16, but still the most of any Canadian telemetry site.

The Whistler ski area has 140" of snowdepth at 5400 ft (135% of normal), below the maximum of 156" on March 16, with 568" of total snowfall to date, its 2nd highest snowfall on record through April 7. This is likely to become only the 2nd season to break 600" at Whistler, trailing the record 673" of 1998-99. By the way, the current #2 snow season was just last year, with 588" in 2009-2010 (snowfall data exists back to 1972-73 at this site).

WA:
Mt Baker Ski Area (4200 ft) hit a new seasonal maximum of 258" on April 6 (about 150% of normal), exceeding its previous seasonal maximum of 253" on March 16, and currently the most of any telemetry site in North America. The ski area also reported a base of 283" at 5000 ft atop Pan Dome, matching its seasonal maximum of 283" on March 17. Seasonal snowfall was finally posted on their website with 682" as of March 17, and about 70-80" more has fallen since then for a total exceeding 750".

Marten Ridge SNOTEL (3520 ft, on the east flank of Mt Baker) reached a seasonal maximum of 192" on April 6, impressive for its comparatively low elevation.
Brown Top SNOTEL (5830 ft, on the long ridge extending east from Mt Redoubt in the North Cascades) reached 197" on April 6, just shy of its seasonal maximum of 202" on March 16-17.
Easy Pass SNOTEL (5270 ft, 8 miles east of Mt Shuksan) has no working snowdepth sensor, but its snow-water equivalent has reached 103" as of April 6, implying a snowdepth of around 240-250".
Buckinghorse SNOTEL (4870 ft, in the Olympics, 12 miles SE of Mt Olympus) has had its snowdepth sensor (mounted much too low) buried by the rising snowpack, and so is stuck reading only 196" since March 10. But it was apparently manually measured at 208" on April 1.
Lyman Lake SNOTEL (5980 ft, 11 miles NE of Glacier Peak) has also apparently had its snowdepth sensor buried by the rising snowpack, and so is stuck reading only 194" since April 1, despite another 3 ft of new snow falling.

Even Stevens and Snoqualmie, which have been struggling to reach normal snowdepths all season, are now solidly over 100% of normal. Stevens Pass reached a seasonal maximum of 139" at 4000 ft on April 6 (about 140% of normal), with 193" atop Skyline Express (5240 ft) and 188" nearby at Grace Lakes (4800 ft). Snoqualmie Pass reached a seasonal maximum of 106" at 3000 ft on April 6 (about 130% of normal), with 122" at the Alpental base (3120 ft) and 207" reported by the ski area atop Alpental (5400 ft).

Paradise reached a new seasonal maximum of 235" on the NWAC telemetry on April 6, far exceeding its previous maximum of 205" on March 29. Snowfall for the season-to-date is reported at 771" as of April 7, with a depth of 245" on the NPS snow stake (a new seasonal maximum and about 140% of normal). Paradise is almost certain to break the 800" mark for snowfall this year, which it has done in only 11 seasons out of 84 years which have total snowfall data (average annual snowfall is 680", the highest average of any measurement site in the world).

Paradise SNOTEL (5130 ft, SW of the old visitor center site) also reached a new seasonal maximum of 207" on April 6.
Cayuse Pass SNOTEL (5240 ft, near the hairpin turn on SR 410 above Cayuse Pass) hit a new seasonal maximum of 221" on April 6, exceeding its previous seasonal maximum of 204" on March 29.
Swift Creek SNOTEL (4440 ft, on the south side of Mt St Helens) has had problems with its snowdepth sensor since January (more and more flaky, then offline), but it was apparently manually measured at 182" on April 1. About 4 ft of new snow has fallen since then, so it probably reached about 220" on April 6.

OR:
Mt Hood, Timberline Lodge (6000 ft) finally and just barely reached the 200" mark on April 6 (about 120% of normal), exceeding its previous seasonal maximum of 185" on March 29, with seasonal snowfall of 624" to date.

No other telemetry sites in Oregon are over 170", although Mt Bachelor Ski Area is reporting a base of 159-179" (at 6300 and 7700 ft), with 577" of snowfall. Crater Lake park headquarters (6400 ft) has a depth of 145" as of April 7 (about 120% of normal), below its seasonal high of 160" on March 29, with snowfall of 578" to date, far surpassing its average annual snowfall of 524".

CA:
In California, the huge March storm cycles (which brought 10-20 ft of snowfall to Shasta, Lassen, and the Sierra Nevada over a 2 week period) ended on March 27-28, followed by sunny weather and almost no additional snowfall through April 6. Snowdepths at many sites (which neared and exceeded 200" during the storms) have now settled by over 40" or even 50" through April 6, when a new system brought another 1-2 ft of snow to the Sierra.

Mt Shasta, Old Ski Bowl (7600 ft) is down to 190" as of April 7, still about 160% of normal, but well off its seasonal maximum of about 230" from March 26-28. The sensor is mounted much too low at this site at only 237" high, and many readings during the maximum period were inconsistent and pegged at this 237" value. The Sand Flat CCSS site (6750 ft, just west of Bunny Flat) is at 145" as of April 7, down from its maximum of about 200" from March 26-28 (this sensor also apparently got buried, with 5 days of no data from March 24-29, and data resuming at 186" on March 29).

Lassen Peak, Lake Helen (8250 ft) is down to 234" as of April 7, still about 130% of normal, but well off its seasonal maximum of 274" on March 26 which was the most of any telemetry site in North America this season. The Lassen Volcanic National Park visitor center (6700 ft) is at 150" as of April 6, down from its maximum of 192" on March 28.

The Meadow Lake CCSS site (7200 ft, north of I-80 and Lake Tahoe) appears to have reached 261" as of March 25 and perhaps 259" as of March 27, but the data was very flaky and intermittent, then all telemetry from the site died completely. A manual snow course measurement showed 228" on March 31.
Independence Lake SNOTEL (8350 ft, 15 miles east of Meadow Lake CCSS site) is down to 167" as of April 6, off its seasonal maximum of 214" on March 25.
Leavitt Lake SNOTEL (9600 ft, west of Bridgeport, well south of Lake Tahoe) is down to 203" as of April 6, off its seasonal maximum of 237" on March 25.

Several other manual monthly snow course sites in the Sierra Nevada also exceeded 200" during the April 1 measurement, see the April measurements here . The overall California snowpack is at 170% of normal, so the 2007-2009 California drought is even more completely over than it was after last year's plentiful late-season snowfall.

The Mammoth Ski Patrol's telemetry site at 9000 ft is down to 160" as of April 6, off its seasonal maximum of 215" on March 25. The nearby Mammoth Pass USBR site (9300 ft) reached 195" on March 21 and again on March 23, apparently that is the height of the snowdepth sensor which got buried at the time. The true seasonal maximum was probably about 225-230" on March 25, which has settled to 176" as of April 6. Snowdepths are building again with renewed snowfall on April 6-7, with seasonal snowfall of 617" as reported by the ski area as of April 7.

Any thoughts about the climatology regarding the clustering of the heavy snow years recently at Mammoth?

I've noticed that heavy snow years are often grouped in six to seven year periods in the Paradise records. Wonder why?

I'm not sure what to say about the clustering effect, or even whether it's real. The brain is adept at "seeing" patterns where none really exist (compare seeing faces in the moon and on Mars and on toast, patterns in clouds, etc). I've never read of any weather pattern with such a time-scale that could be the cause. But I've seen the same thing you see in the Paradise snowfall data, too.

Here's a comparison of the annual snowfall stats at Whistler and Mammoth, which both appear to show similar clustering for certain several-year periods (blue line is the current mean, red line the running mean):





Since I first analyzed the Whistler and Mammoth data several years ago (these sites both had good monthly snowfall data available online unlike almost all other ski areas, and extending back 30-40 years), I've been fascinated by the comparison between the snowfalls at these two massive ski areas. Both have surprisingly similar averages and maxima, but statistically the data sets are very different. Mammoth has a median of 392" with a standard deviation of 138", while Whistler has a median of 394" with a standard deviation of 99". Mammoth has much more variability, with many more huge seasons (4 years over 600") and also far more disastrous years (3 years under 200", with a shocking low of 90") compared to Whistler which is much more consistent (only 1 year over 600" and none below 200").

There are roughly 900 miles and 13 degrees of latitude (37.6 to 50.1 N) between Mammoth and Whistler, and weather patterns which favor one with heavy snowfall tend to leave the other dry. So the fact that this year and last year have both been huge at both ski areas is very odd, especially since 2009-2010 was an El Nino winter and 2010-2011 a La Nina winter. It is highly unusual for these two locations to have near-record snowfalls in the same season as they are doing now, with both likely to end up with their second highest snowfall years.

And even more so this season, it's unusual for essentially every mountain measurement site between those points 900 miles apart to have above normal snowdepth as they do now. Seasonal maxima have reached about 120% of normal in this year's least favored parts of the WA and OR Cascades (Stevens, Snoqualmie, and Hood), but over 150% of normal in southwest BC, the Olympics, and northern WA Cascades, and as much as 180-200% of normal on Shasta and at many sites in the Sierra Nevada. Much of the Rocky Mountains (north of New Mexico at least) has also had a banner snow year, as has the East Coast both in the lowlands and the Appalachian Mountains. That's the most remarkable thing about the 2010-2011 snow season, the vast geographic extent of much-above-normal snowfall in North America.

Amar (and Gary),
This is a facinating thread - thanks for finding all the data and collecting it all in one place.

Utah is also doing well, with Alta reporting 609" year to date and a base of 184" as of April 8. A lot more snow is in the forecast as well.

Thanks, again, Amar. Really cool stuff. I don't think I'd have noticed the clustering if I hadn't also seen it in Rainier's data. I remember walking into the old visitor's center and seeing a board with the annual snowfall totals. To me Rainier's data also had the same pattern both for good and bad periods as we see on the Mammoth data.

I've sometimes thought that looking at spring/summer weather seems to show a pattern over several years that is even more perceptible than the one that may be showing up in winter. For instance, up until about three years ago the springs seemed to arrive early and the summers seemed to be warmer and especially drier than normal with long periods without rain. Then over the past three summers, each summer has been worse than the one before with last summer taking the cake.

I'm guessing here, but I kind of think that there are longer patterns in the range of 6 to 7 years that have to have more than just El Nino and La Nina to explain them. As a matter of fact (to use the term loosely) it may be that last spring and summer's bad weather presaged this winter's La Nina even before sea surface temperatures showed the approach of La Nina. Something, but what?

Thought I'd add this to the thread concerning climatological NW snow depths as compared to the present (from NWAC):

www.nwac.us/data/CLISNO

Here's the actual CLISNO data for April 1, posted for posterity:

CLIMATOLOGICAL SNOWDEPTH INFORMATION
NORTHWEST WEATHER AND AVALANCHE CENTER SEATTLE WASHINGTON
DAY  1  MONTH  4  YEAR  2011

DATA IN INCHES, -99 DENOTES MISSING DATA

            CURRENT  CLIMATE  PER CENT   LAST  THRU 2010  THRU 2010
            DEPTH    AVERAGE  OF NORMAL  YEAR  MAX/YEAR   MIN/YEAR

HURRICANE   153      105      146        110   252/1999    42/2005
MT BAKER    230      173      133        173   311/1999    72/1934
STEVENS     108      101      107         84   192/1956    24/1941
SNOQUALMIE   82       85       96         51   170/1956     2/1992
STAMPEDE     82      100       82         58   183/1956    17/1992
MISSION      58       47      123         47    86/1983    20/1973
CRYSTAL      97       71      137         81   144/1999    16/1981
PARADISE    208      174      120        153   327/1956    66/1941
WHITE PASS   62       56      111         54   110/1997     0/1992
TIMBERLINE  165      164      101        155   300/1999    57/1981
MEADOWS     129      129      100        125   199/2008    49/2005


April 1 is normally the most important day of the year for snowpack and snowdepth measurements, since on average the snowdepth maximum occurs near April 1 at most mountain sites of sufficient elevation, throughout the western US and southwestern Canada. Most water resources predictions for the summer are based on April 1 snowpack data (snow-water content). Unfortunately, by random chance this year, April 1 was not a very good day for big snowdepths in WA and OR, coming after the huge rainstorm which dumped 4-8" of precip at snow levels reaching 7000+ ft on March 29-31.

Even though the rainstorm did not reduce snowdepths much, it did nothing to help them, and then immediately afterward was followed by heavy snowfall at much lower snow levels. Thus several sites look near or below normal in that table, when they no longer were so low even a few days after April 1. Snowdepths increased by 2-3 ft at those sites by April 6, putting all sites over 100% of normal. The continued snowfall since then will ensure that the April 15 CLISNO looks much more favorable when it comes out.

It looks to me as though the area around Kyes Peak/Cadet Glacier is the big winner this year (although obviously not a weather station). There is so much snow Cadet Glacier can't even be spotted. The snow in this region looks far deeper than even Mt. Baker and environs.

Don't forget about little old Mt. Washington, Vancouver Island, BC. Currently reporting 652cm's or 257" base.

Looks like Crystal, Paradise and Timberline all hit seasonal snowpack highs today (Aptril 15). 241 inches at Paradise - nice!

Should be able to bump up those seasonal records at many locations the next few days.....

The continued snowfall since then will ensure that the April 15 CLISNO looks much more favorable when it comes out.

Here's the actual CLISNO data for April 15, belatedly posted for posterity, and looking much fatter than the April 1 numbers:

CLIMATOLOGICAL SNOWDEPTH INFORMATION
NORTHWEST WEATHER AND AVALANCHE CENTER SEATTLE WASHINGTON
DAY  15  MONTH  4  YEAR  2011

DATA IN INCHES, -99 DENOTES MISSING DATA

            CURRENT  CLIMATE  PER CENT   LAST  THRU 2010  THRU 2010
            DEPTH    AVERAGE  OF NORMAL  YEAR  MAX/YEAR   MIN/YEAR

HURRICANE   177      109      162        111   252/1999    51/2005
MT BAKER    253      167      151        184   290/1999    56/1934
STEVENS     125       93      134         86   170/1956    17/1941
SNOQUALMIE  100       72      139         56   153/1974     0/1992
STAMPEDE    111       98      113         68   216/1964     9/1992
MISSION      57       45      127         51    79/1983    21/1990
CRYSTAL     112       73      153         86   130/1999    30/1981
PARADISE    240      172      140        163   302/1972    68/1934
WHITE PASS   80       45      177         53    95/1997     0/1992
TIMBERLINE  203      164      124        163   300/1999    71/1977
MEADOWS     157      127      124        131   194/2008    54/2005



Numerous sites did reach new snowdepth maxima on the 15th, primarily in the region from Rainier south to Hood, and these same locations are likely to be reaching new seasonal maxima this week. In fact, Timberline has just reached a new maximum of 208" in the last hour (exceeding its prior mark of 206" set later in the day on April 15), as has Crystal Green Valley with 162" (had been 159" on April 15). The Crystal base area and Mt Hood Meadows are each now within 1" of their April 15 maxima, so they may pass those later today, or by Thursday with the next incoming storm.

The final CLISNO update on May 1 is likely to be very high as a percent of normal, coming out just after this week's major cold storms.

Revisiting the original topic of this thread: Mount Rainier Paradise remains several inches below its 240+" seasonal maximum of April 15 as of today. However, it did pass the 800" mark for snowfall on April 14, and was up to 838" as of yesterday according to the park's phone message today. With 13" more of new snow today (see the official daily NPS measurements for Paradise for the last month ), that would put it at about 851" for the season, the 10th highest seasonal snowfall on record at Paradise in 84 years of snowfall data.

With the next storm likely to dump another 2-3 ft on Wednesday-Thursday, and given its average snowfall of 23" in May and 6" in June, it is very likely that Paradise will break the 900" mark this season, something which it has done only 7 times before (last time was 947" in 2007-. That was my pre-season prediction, that Paradise would break 900" this year, based on its average snowfall in strong La Niña years of 915". A prediction that looked to be highly erroneous by the time mid-February rolled around and the snowfall total was still hovering near 450", but now looking much closer to the mark.

Amar,

You are the expert so I am asking this question to you.

How come when I read snotel data for Year-to-Date Precipitation, the accumulated precipitation amount will go down as well as up? I understand going up...but whay does the Year-to-Date Precipitation go down from one reading to the next over several hours?

Here is an example:
www3.wcc.nrcs.usda.gov/nwcc/sntl-datarpt...s=7&state=washington

Thanks for helping me understand the data!

Stefan

How come when I read snotel data for Year-to-Date Precipitation, the accumulated precipitation amount will go down as well as up?  I understand going up...but why does the Year-to-Date Precipitation go down from one reading to the next over several hours?

This FAQ from the Idaho SNOTEL site has info about precip gauge errors, see question #2: www.id.nrcs.usda.gov/snow/faq/snow_prec_faq.html

Q2. How can year-to-date precipitation decrease? For example, Trinity Mountain SNOTEL’s precipitation was 7.8 inches then the next reading shows 7.7 inches. Shouldn’t cumulative precipitation always be increasing?

Cumulative precipitation should only increase through a water year, however we allow small decreases in raw precipitation data (less than -0.5 inches) so that it passes through our automatic quality checks. This allows the data to be included in our data reports. For large decreases (greater than -0.5) the data is flagged suspect and will show up as a -99.9, those values are kept out of data reports. The reasons you might observe decreases include...

1. The voltages that our electronic pressure transducers use to measure precipitation and snow water can flutter up and down with temperature changes. This is particularly evident in hourly data, since diurnal temperature changes cause greater fluctuations than readings taken on consecutive midnights, when we measure daily data.

2. There might be an air bubble in the plumbing line leading to the transducer. Temperature changes cause the air bubble to expand and contract and this is another reason for measurement flutter. Bleeding the air out of all plumbing lines is one of our common field maintenance practices.

3. The data you are looking at hasn't been manually quality checked yet. We do weekly edits each Monday to smooth these kinds of flutter out of the daily data. Generally in a day or two the data will rebound to where it was and we'll edit out the low value the following Monday. The hourly data is raw and it does not undergo this weekly quality checking process so decreases remain in those data sets. If a precipitation decrease is observed in daily data that is more one water year old, it should be brought to the attention of the snow survey as it should be corrected.

4. The final case is there is something wrong at the site. There are various problems that can cause a precipitation gage to decrease. These include leaks caused by an animal such as a bear or mouse chewing a hole in the plastic plumbing, or a human vandalizing the gage with bullet holes. When a leak is suspected we schedule a repair trip to the SNOTEL site to fix it. Until the repair is made we edit the data using nearby sites or during the winter we'll estimate precipitation using the snow pillow.

Regarding the Hozomeen Camp site that you linked to, the answer is that the precip gauge at that SNOTEL site appears to be malfunctioning, and the NRCS SNOTEL staff is aware of the issue. If you look at the midnight (0000) values of the data, you'll notice that they are all exactly 38.7", regardless of what the adjacent values at 2300 or 0100 might be. The midnight values are checked and quality controlled by NRCS staff, and in this case they've clearly been manually edited to all be equal to 38.7".

This shows the last 30 days of midnight values only (www3.wcc.nrcs.usda.gov/nwcc/sntl-data000...=30&state=washington), and it looks like the problem began just before April 17, since all midnight values have been constant at 38.7" since then, despite continuing precipitation.

That 65" snowfall was partly responsible for me moving out to Seattle -- iI wanted to move someplace with real mountains and big snowfall. Choosing the UW and moving to Seattle remains the single best decision I've ever made in my life (my mom disagrees, she nearly went apoplectic at my decision, and still can not believe that I chose the UW over Yale).

Wise move! I did a post-doc at Yale, then joined the faculty (School of Medicine). I loved the diversity of visiting seminar speakers in my field (ecology), but that was it; very limited in access to mountains :'( but I ended up in WA almost by accident (was strongly urged to come here by my employer) and once here for nearly a decade, I began skiing for the first time in my life. 20 years later, bc skiing remains my passion as does hiking the subalpine and alpine in Mt. Rainier.

Thanks Amar!

With the next storm likely to dump another 2-3 ft on Wednesday-Thursday, and given its average snowfall of 23" in May and 6" in June, it is very likely that Paradise will break the 900" mark this season, something which it has done only 7 times before (last time was 947" in 2007-. That was my pre-season prediction, that Paradise would break 900" this year, based on its average snowfall in strong La Niña years of 915". A prediction that looked to be highly erroneous by the time mid-February rolled around and the snowfall total was still hovering near 450", but now looking much closer to the mark.

Well, that happened very quickly: Paradise has already broken 900" of snowfall for the season, with the park phone recording reporting 902" as of this morning. This is now the 8th highest seasonal snowfall on record at Paradise in 85 years of snowfall data. There has been 23" of new snow at Paradise so far in May, which equals the normal amount for the entire month of May.

The maximum snowdepth at the NPS snow stake this year was 253" on April 28, which is the 13th greatest seasonal maximum out of 93 years that have data for seasonal maxima. It's also 1" more than the seasonal maximum from 2007-2008 (252" on March 29, 2008), which was the most recent strong La Niña year with 947" of snowfall.

However, the late season values are even more impressive this year, as the May 1st snowdepth is the 6th greatest on record. As of today (May 9), the current snowdepth is 242", and the only other seasons which have had snowdepths over 240" this late are 1916-17, 1955-56, 1971-72, 1973-74, and 1998-99, which were all HUGE snow years with over 1000" of snowfall.

---

Here's the final CLISNO data for this season for May 1, looking very impressive across the board as a percent of normal:

CLIMATOLOGICAL SNOWDEPTH INFORMATION
NORTHWEST WEATHER AND AVALANCHE CENTER SEATTLE WASHINGTON
DAY  1  MONTH  5  YEAR  2011

DATA IN INCHES, -99 DENOTES MISSING DATA

            CURRENT  CLIMATE  PER CENT   LAST  THRU 2010  THRU 2010
            DEPTH    AVERAGE  OF NORMAL  YEAR  MAX/YEAR   MIN/YEAR

HURRICANE   169       91      186         89   145/1982    25/2005
MT BAKER    241      138      175        166   270/1999    20/1934
STEVENS     113       81      140         72   141/1964    13/2005
SNOQUALMIE   87       59      147         33   131/1974     0/2005
STAMPEDE     98       80      122         57   176/1964     0/2005
MISSION      52       33      158         33    56/1999     0/2005
CRYSTAL     107       72      149         76   115/1999    17/2005
PARADISE    244      159      153        158   295/1972    36/1941
WHITE PASS   66       29      228         29    76/2008     0/2005
TIMBERLINE  211      153      138        159   270/1999    43/1977
MEADOWS     156      114      137        118   189/2008    30/2005

Great data Amar!

Do you (or anyone else) know if there's a direct correlation between record snow years, and summer weather trends?

Time for some updated and still-astounding numbers as of June 1, as the historically cold and wet Northwest spring of 2011 continues to cap off this record-setting snow season:

Snowdepth at Paradise as of June 1 is 213" on the NPS snow stake (203" on NWAC telemetry). This is the 2nd greatest June 1 snowdepth out of 91 years which have June 1 data -- wow! This year trails only 1974 which had an outrageous 245" depth, and exceeds 1972 (209"), 1999 (204"), 1971 (199"), and 1917 (198"). Average June 1 snowdepth is 114", so this is almost 190% of normal snowpack now. Last year (which had the best mid-summer skiing conditions in well over a decade or longer), the June 1 snowdepth was only 142" (125% of normal). At the other end of the scale, only two years have had zero snowdepth at Paradise on June 1: the cruel seasons of 1941 and 2005.


[size=small]Still snowing hard at Paradise on the morning of June 1, 2011.[/size]

The seasonal maximum NPS snowdepth was 253" on April 28, while the NWAC telemetry reached 241" on both April 15 and April 28.
Unfortunately, the total snowfall numbers for the season at Paradise somehow got "revised" (or screwed up?) in late May, strangely dropping back under 900" after reaching 902" on May 9 -- the number is back up to exactly 900" as of June 1 on the park phone recording.


Snowdepths are now generally 170% to over 300% of normal at most mountain sites from southwestern BC through the entire Cascade Range and Sierra Nevada, while new season snowfall records were set at several ski areas in WA, OR, and CA. Other June 1 values for stations which I've been following in this thread:

BC:
The Upper Squamish River BCRFC site (4500 ft, west of Whistler and Mt Cayley) is at 164" as of June 1, roughly 200% of normal, and as usual the most of any Canadian telemetry site. The seasonal maximum was 239" on March 16.

The snowiest measurement site in Canada, however, is the monthly manual snow course at Orchid Lake (3900 ft) south of Mt Garibaldi. The snowdepth as of May 31 is 195" (over 180% of normal). A maximum snowdepth of 256" was recorded at this site during the April 7 snow survey, the greatest snowdepth recorded at any official site in Canada this season as far as I know.

The Whistler ski area has 107" of snowdepth at 5400 ft (170% of normal) as of the final day of winter operations (and snow reports) on May 30. Total snowfall for the season (November-May) was 622", making this only the 2nd season to break 600" at Whistler, trailing the record 673" of 1998-99 and surpassing the 588" in 2009-2010 which was the former #2 season. Average annual snowfall is about 417", so this is 150% of normal snowfall.

WA:
Mt Baker Ski Area (4200 ft) is at 199" as of June 1, just barely dropping under 200" since yesterday. Average June 1 snowdepth is roughly 80", so this is about 250% of normal! The seasonal maximum was 258" on April 6, nearly matched by reaching 254" on April 28. Snowfall for the season at the ski area was 857" from November-April, not including any snowfall in May, which would bring it close to 900" for the season, far over the annual average of about 650".

Hurricane Ridge (5260 ft) has 118" as of June 1, with a seasonal maximum of 166" on April 14.
Washington Pass (5500 ft) has 80" as of June 1, with a seasonal maximum of 131" on April 6.

Stevens Pass still has 78" of snow at 4000 ft, which is over 300% of normal for June 1, and its seasonal maximum was 139" on April 6. The snowdepth is still 130" at Grace Lakes (4800 ft) and 147" atop Skyline Chair (5240 ft), which had seasonal maxima of 188" and 193" at those sites on April 6. The ski area recorded 514" of snowfall for the season from November to mid-April, just over their annual average of about 490".

Snoqualmie Pass has only 35" of snow left at 3000 ft, but that is over 500% of normal which is only 6" on June 1. The seasonal maximum was 106" on April 8. The WSDOT recorded 497" of snowfall at Snoqualmie Pass through May 22, exceeding the long-term annual average of about 440" despite a very dry mid-season. Alpental still has 70" at 3120 ft as of June 1, while its seasonal maximum was 122" on April 6 with 207" reported by the ski area atop Alpental (5400 ft).

Crystal Mountain ski area set a new snowfall record this season , with 609" in Green Valley as of June 1, topping their previous record of 596" from 1998-99 and over 160% of normal (about 360"). Snowdepth as of June 1 is still 88" at the base (4480 ft) and 141" in Green Valley (6300 ft), both over 200% of normal. The seasonal maximum was 115" on April 28 at the base and 164" on April 29 in Green Valley. The ski area plans to remain open for skiing on weekends only well into June and possibly July.


[size=small]Exceptional snow coverage remains at Crystal Mountain on June 3, 2011.[/size]

Cayuse Pass SNOTEL (5240 ft, near the hairpin turn on SR 410 above Cayuse Pass) still has 179" as of June 1, while its seasonal maximum was 228" on April 15.
Swift Creek SNOTEL (4440 ft, on the south side of Mt St Helens) has had problems with its snowdepth sensor since January (more and more flaky, then offline), but daily midnight values of snowdepth are being calculated by NRCS staff and edited into the data. This value as of June 1 is 172" (well over 200% of normal), with a seasonal maximum value of 218" on April 29.

OR:
Mt Hood, Timberline Lodge (6000 ft) has 184" as of June 1 (roughly 180% of normal), with a seasonal maximum of 218" on April 29. Seasonal snowfall at the ski area is 739" to date. Timberline may actually have enough snow to remain open all summer (except the usual 10-day maintenance closure in early fall), which it hasn't quite managed to do most of the last few years.

Mt Hood Meadows (5250 ft) has 117" as of June 1, with a seasonal maximum of 166" on April 29. Seasonal snowfall at the ski area was 624" through their closing date of May 15.

Mt Bachelor Ski Area set a new snowfall record with 665", shattering their previous record of 606" from 1998-99 and over 170% of normal (387"). Snowdepth as of their closing weekend on May 28 was 129" at the 6300 ft base, with 175" at 7700 ft. The ski area has posted an interesting recap of their 2010-2011 season online .

Crater Lake park headquarters (6400 ft) has a depth of 119" as of June 1 (240% of normal), with a seasonal high of 160" on March 29. This is the largest June 1 snowdepth since 1983 which had 121" left on June 1 following Crater Lake's all-time record snowdepth of 252" on April 3, 1983. Snowfall for this season is now up to 671" as of June 1 (130% of normal), the 9th greatest snowfall total in 84 years of records and far surpassing its average annual snowfall of 524". Snowdepth at the crater rim (7050 ft) is 165" as of June 1, with a seasonal maximum of 174" on April 26 (several lengthy data outages this season, so the true maximum may have been greater on another date).


[size=small]Deep snowpack at Crater Lake park headquarters (6400 ft) on the afternoon of June 1, 2011.[/size]

CA:
In California, the huge March storm cycles (which brought 10-20 ft of snowfall to Shasta, Lassen, and the Sierra Nevada over a 2 week period) ended on March 27-28, followed by mostly sunny weather and only a small amount of snowfall throughout April. Stormy weather resumed in May, with multiple storm cycles bringing several feet of additional snowfall, and heavy snow is continuing to fall into the start of June.

Mt Shasta, Old Ski Bowl (7600 ft) has 170" as of June 1 (roughly 300% of normal) with 14" of new snow in the last 36 hours. The seasonal maximum was about 230" from March 26-28. The sensor is mounted much too low at this site at only 237" high, and many readings during the maximum period were inconsistent and pegged at this 237" value. The Sand Flat CCSS site (6750 ft, just west of Bunny Flat) has 109" as of June 1 (over 400% of normal) with 11" of new snow in the last 36 hours. Its maximum was about 200" from March 26-28 (this sensor also apparently got buried, with 5 days of no data from March 24-29, and data resuming at 186" on March 29).

Lassen Peak, Lake Helen (8250 ft) has 229" as of June 1 (roughly 200% of normal) with 10" of new snow in the last 24 hours. Its seasonal maximum of 274" on March 26 was the greatest snowdepth recorded at any telemetry site in North America this season, and its current value is still tops among all sites. This site has two snowdepth sensors, the primary one mounted at 297" above ground and an auxiliary sensor (on another tower?) at 357" high -- the auxiliary sensor has 218" as of June 1, while its seasonal maximum was 262" on March 26.


[size=small]Still snowing hard at the Lassen Volcanic National Park visitor center (6700 ft) on the afternoon of June 1, 2011.[/size]

In the Sierra, all ski areas except Mammoth are now closed for the season, but given the deep snowpack remaining now, a few of them (Sugar Bowl, Alpine Meadows, Squaw Valley) are planning to reopen for the 4th of July weekend according to their websites.

Squaw Valley shattered its all-time season snowfall record by about 100", with 496" at the 6200 ft base and 789" at 8200 ft through its closing date on Memorial Day. It had never broken 700" before. See their complete daily snowfall data .

Sierra-at-Tahoe also broke its snowfall record this season with 763" at its upper 8850 ft measurement site. They also post complete daily snowfall data .

It appears that only two SNOTEL sites in the Sierra exceeded 200" of snowdepth this season:
Independence Lake SNOTEL (8350 ft, north of I-80 and Lake Tahoe) still has 137" as of June 1, far below its seasonal maximum of 214" on March 25.
Leavitt Lake SNOTEL (9600 ft, west of Bridgeport, well south of Lake Tahoe) still has 178" as of June 1, an impressive total but well off its seasonal maximum of 237" on March 25.

Mammoth Mountain has a snowdepth of 108" at the 8900 ft main lodge and 204" higher up as of June 1, with season snowfall of 664" as reported by the ski area . This is only 4" shy of the 668" in 2005-6 which was widely reported as its all-time record snowfall. Season snowfall is 649" as reported on the Mammoth Ski Patrol's pages , which is a new record far surpassing the 578" recorded by the patrol in 2005-6. Their telemetry site at 9000 ft still shows 110" as of June 1, far below the seasonal maximum was 215" on March 25. Mammoth Mountain ski area is planning to remain open until July 4, and perhaps longer -- its latest closing date was August 13 in 1995.

Bump: Updated the previous post on June 3 to include several missing/revised values, plus added some photos.

Wow, Amar,
It seems like there might even be a minuscule chance that Paradise may hold 200 inches through the summer solstice.

Sorry, Ron, it looks like the past weekend's warm weather finally started melting off significant snow: the Paradise snowdepth has already fallen below 200", with 195" at the NPS snow stake as of today June 7, and 187" on the NWAC telemetry. Even during 1974 which had the deepest late-spring and summer snowpack on record, the snowdepth only remained above 200" until June 18, a few days short of the solstice.

Lassen Peak, Lake Helen (8250 ft) still has 224" as of June 7, the only telemetry site in North America still over 200". That's a decrease of only 5" since June 1, as roughly another foot of new snow has fallen there since then. Sustained sunny weather is moving in today though, so even Lassen is unlikely to stay above 200" more than another week or so.