A little breezy on the east side....

Mission Ridge is getting absolutely destroyed with this storm!  Since 4 am this morning the 'low' gusts have stayed in the 70-80 mph range while the high gusts reported have topped 130 mph (yet again)! 

www.nwac.us/~nwac/products/OSOMSR

It's going to be scary to see the aftermath...

I wonder if when they fixed the windows that got blown out in the last storm they did so assuming they would get winds just as strong (but longer lasting) 3 weeks later.  The winds in the Dec 14-15 storm, to my memory, where due to a different mechanism than those occurring now.  Looking at weather models, it seems that these winds are due to intense lee throughing on the east slopes with the strong westerly flow aloft.  I would be interested to see what other east side ranges are seeing right now.  Check out the sea level pressure contour density near Lake Chelan. Pangborn Airport in Wenatchee just recorded a gust of 57 knots! As for whether or not Mission is the windiest place, I would think, due to things like this, that it is probably the windiest for its elevation, and probably the windiest instrument site in the state. Too bad there is no anemometer on the summit of Rainier.

Pangborn also went from 30 F to 40 F in one hour.

I remember reading somewhere on the internet that the highest wind gust ever recorded on Mission was 132 mph. Maybe this is a new record?

I believe the 135mph gust was not only the strongest Mission has recorded, but likely the highest winds (below Muir) ever recorded on NWAC telemetry. There are no "official records" that have been kept, although the back data is saved - at least for a number of years.

I've been curious about this ever since your posts. I finally found a couple of hours right now to go through the Mission Ridge telemetry data and find the record wind gust. Here's a summary of each season's maximum wind speeds (plus any other dates with 100+ mph winds) since the telemetry site was installed in 1988:

[tt]1988-89:  89 mph 17Jan1989
1989-90:  83 mph 10Feb1990
1990-91:  83 mph 19Dec1990
1991-92:  66 mph 11Dec1991
1992-93:  72 mph 24Jan1993
1993-94:  68 mph 04Jan1994
1994-95:  85 mph 28Dec1994
1995-96:  71 mph 27Feb1996
1996-97: all data missing
1997-98:  74 mph 26Mar1998
1998-99: 136 mph 02Feb1999; also 100 mph 26Dec1998, 108 mph 14Jan1999, 100 mph 19Feb1999
1999-00: 116 mph 15Dec1999 and 09Jan2000
    also 101 mph 11Dec1999, 103 mph 17Dec1999, 105 mph 08Jan2000, 108 mph 14Mar2000, 100 mph 18Mar2000
2000-01: 112 mph 15Dec2000
2001-02: 112 mph 11Mar2002; also 103 mph 20Jan2002, 106 mph 19Mar2002, 100 mph 16Apr2002
2002-03: 101 mph 03Jan2003; also 100 mph 26Dec 2002 and 11Mar2003
2003-04: 106 mph 30Jan2004; also 102 mph 05Mar2004
2004-05:  80 mph 12Jan2005
2005-06: all data missing after late Dec[/tt]

These values were extracted directly from the original NWAC data files (many thanks to Garth Ferber for making these available). I've tried to purge any obviously erroneous values in the data prior to searching for each season's maximum, but some of the values listed above may nevertheless be wrong, since I have no control over the quality of the original automated telemetry data and there is some missing data every season. It might be useful to double-check the plausibility of these earlier values by making sure there was actually a major storm on these dates. According to the Daily Weather Map Archive , a powerful 988 mbar low hit the BC coast on 02Feb1999, producing a strong pressure gradient throughout WA, so the 136mph reading does meet a simple plausibility standard. I haven't bothered checking any of the other dates.

So it appears that the previous record was 136 mph in 1999, and the 135 mph on 15Dec2006 fell just short . . . until today's 137 mph mark. Here are the dates this season with 100+mph winds:
[tt]  111 mph  13Nov2006
  121 mph  13Dec2006
  135 mph  15Dec2006
  113 mph  02Jan2007
  137 mph  07Jan2007
  134 mph  09Jan2007[/tt]

Clearly 2006-7 is an extremely unusual season for high-wind storms in the central WA Cascades, with the half-dozen storms hitting 110+ mph surpassing the total number during the previous 15 years of data. And the 20 consecutive hours with 100+ mph maxima between 0400 and 2300 on 07Jan2007 (see table below) is COMPLETELY unprecedented in the history of the Mission Ridge telemetry site, most other high wind events only last a few hours (100+ max winds for 1-3 hours). Perhaps the Mission Ridge anemometer just has some slippery new bearings this year . . . ?

[tt]
Northwest Weather and Avalanche Center
Mission Ridge Ski Area, Washington

MM/DD  Hour  Temp  Temp  Temp    RH    RH  Wind  Wind  Wind  Hour Total 24 Hr Total
         PST     F     F     F     %     %   mph   Max   Dir Prec. Prec.  Snow  Snow
             6740' 5300' 4600' 6740' 5300' 6740' 6740' 6740' 5300' 5300' 5300' 5300'

---

   1 6  2300    15    22    25    94   100    39    54   226     0     0     0    51
   1 7     0    15    22    25    94   100    37    50   225     0     0     0    52
   1 7   100    15    22    25    94   100    36    46   225   .02   .02     0    52
   1 7   200    15    22    25    95   100    45    65   228   .03   .05     0    51
   1 7   300    19    24    26    96   100    58    86   239   .03   .08     0    52
   1 7   400    21    27    31    97   100    70   102   241     0   .08     0    52
   1 7   500    22    28    32    97   100    71   111   253     0   .08     0    52
   1 7   600    24    30    34    98   100    77   126   252     0   .08     0    52
   1 7   700    25    31    35    98   100    79   120   254     0   .08     0    52
   1 7   800    25    31    35    98   100    79   129   256     0   .08     0    52
   1 7   900    25    31    34    98   100    81   132   257   .03   .11     0    52
   1 7  1000    26    31    33    98   100    78   123   259   .04   .15     0    51
   1 7  1100    26    32    33    98   100    79   126   260   .02   .17     0    52
   1 7  1200    26    32    34    98   100 -6999   134   260   .01   .18     1    52
   1 7  1300    26    31    34    98   100 -6999   135   265   .01   .19     1    53
   1 7  1400    25    31    34    98   100 -6999   136   271     0   .19     1    53
   1 7  1500    24    30    33    97   100 -6999   136   272   .01    .2     1    53
   1 7  1600    24    30    34    98   100 -6999   134   273     0    .2     1    53
   1 7  1700    25    30    35    98   100    82   137   275     0    .2     1    53
   1 7  1800    24    30    35    98   100    78   117   275     0    .2     2    53
   1 7  1900    24    30    35    98   100    78   123   273     0    .2     1    53
   1 7  2000    24    29    34    97   100    75   116   275     0    .2     1    52
   1 7  2100    23    29    34    97   100    65   100   278     0    .2     1    53
   1 7  2200    22    28    33    97   100    67   113   278     0    .2     1    53
   1 7  2300    22    28    33    97   100    58   105   285     0    .2     1    53
   1 8     0    21    26    31    96   100    30    59   304     0    .2     1    52
[/tt]


(Edited on 09Jan2007 to include that day's new storm info, plus added info on older 100+ mph storms.)

I wonder if the wind avg at Mission registered the -6999 today because NWAC telemetry is unable to record triple digit averages.

What the ?!?!?  Mission Ridge is up to 134 mph again in the past couple hours, less than 2 days after the previous record-setting storm. Something strange is going on this season . . . a half-dozen storms hitting 110+ mph is more than the total number during the previous 15 years of data.

Obviously there's been an extreme number of powerful storms this season, but is it possible that the installation of the Liberator Express high-speed quad in the summer of 2005 has changed the wind flow past the anemometer, perhaps by removing some trees or forcing the wind to accelerate slightly as it flows around the upper lift terminal? According to an article in the Seattle-PI , "The upper terminal for the express lift is in a spot 750 feet beyond and 50 feet higher than the old double." How close to the top of the lift is the NWAC telemetry site?  Maybe I'll have to head over to Mission Ridge and take a look around when they finally reopen.


(And I'm not sure what the -6999 error code means, but the previous record gust of 136 mph in 1999 also has -6999 for the average that hour. Maybe Garth will see these posts and reply.)