Monday, September 04, 2017

Seasonal Summary

Every season has it's own peculiar events, the summer of 2017 was no exception.  A lot of it was dictated by the weather and route conditions but let me start off with some climber statistics.
So far this year (all of 2017) we have had 10,384 registered climbers, which is only a few less then the 2016 season.  Out of that number 68% have been on the DC, 18% Emmons-Winthrop, 5% Kautz Glacier, 2% Furhers Finger, 1% Liberty Ridge, 1% Gibraltar Ledges, etc.  Success rate for all routes has been hovering in the lower 50 percentile, which is a little on the low side but nor extreme.
Smoke did make for some photogenic sunsets and sunrises.
It was a wet and cool winter across the Northwest which of course generated a solid snowpack at the beginning of the climbing season. As of mid-May the snotel site just below Paradise was indicating that the snowpack was 174% of normal.  However due to warm weather from mid-June onwards this deep snow melted out a week earlier than the long-term average date (mid-July).
   May: Air temps and precip were normal; there were alternating periods of clear weather with short-lived storms.  We had two windstorms high on the mountain early in the month:  sustained winds were on the order of 60 mph with gusts in the 80's, (strongest recorded gust of the season was on May 5th at 88 mph).  Route conditions were good with considerable traffic on the Ingraham Direct alternate.  Skiers were common place on the upper DC and Fuhrers Finger routes.
   June: Early June was a continuation of May.  However from June 15-19 a major low pressure system out of the Gulf of Alaska moved onshore and produced 3.89 inches of rain at Paradise with lots of snow on the upper mountain.  Due to wind drift snow totals form this storm ranged from zero to several feet- this shut down climbing not only during the storm but for days afterward due to avalanche potential.  After this storm there was a major shift in the position of the East Pacific Ridge which blocked storms from reaching the Northwest.  The result was the start of a very warm period that is continuing until the present.  Marine stratus clouds were common but no more so than in a typical June.
   July: Hot and dry was the theme.  No rain was recorded around the mountain during the month.  July 20th was the only time that the temperature sensor at Camp Muir (10,188 ft) dipped to freezing- otherwise temps were mainly in the 40's and 50's.  A windstorm did hit the upper mountain from the 5-7th with sustained winds in the low 60's and gusts reaching 77 mph (respectable for a mid-summer storm).  There were a number of days around the lower mountain where the marine stratus was thick and persisted well into the afternoon hours.  However, the tops of these clouds were on the order of 8,000 ft so the upper mountain continued to bake.
   August:  The heat during July was only a preview of coming attractions.  Freezing levels were ridiculous high all month- generally between 14-16K.  On the 11th an air mass thunderstorm passed by the east side of the park, not much rain fell but lighting from these event ignited a number of fires near the Norse Creek Wilderness which have continued to burn.  The only recorded rain during the month was on the 13th when Paradise was blessed with 0.45 inches during the morning hours.  This was the only time that Camp Muir had air temps at the freezing mark. This rain closed out the first of a number of smoke events which have plagued the mountain since the beginning of the month. 
   September: So far nothing has changed in terms of heat and smoke.  The weather models are indicating a system moving onshore on the 7th which will blow smoke back to the east and hopefully bring some cooler temps and showers.
The graph to the right shows the average freezing level for the months of July and August- its pretty clear that this period holds the record for the highest FL since this dataset was started in 1948.  There were three days where air temps at Camp Muir reached into the lower 60's.  There were many nights were the low temps were in the lower to middle 50s.  What was lacking this summer was the presence of locally generate cumulus clouds.  It was just too hot and dry for these to form.
The heat and sunshine took its toll on the mountain.  The DC route went through numerous alterations during August- with a very long indirect path in use most of the month. There were a number of times when snow bridges collapsed making the route un-climbable for several days. Other routes held up a bit better through the heat- the Kautz Glacier was climbable through late August while the Emmons-Winthrop is still doable but with some challenging navigation high-up.
We can only wonder what 2018 will bring!