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[pct-l] Snow Update 5/23/1005



I received a call from the presumed leaders. They were in Tehachapi,
planning to make Kenney Meadows 5/31. They reported that most thruhikers are
walking the road as opposed to walking the trail and plan to flip-flop.
Mountaineers from England they, however, are purists and have stayed on the
trail.

They asked about the status. The status is as follows.

All rivers will crest this weekend. However, the shape of the crest is much
different. In the north [Yosemite and above] the flow will drop off
dramatically after this weekend. In the south there is not much difference
between this weekend and next weekend. They asked if waiting 10 days would
make a difference in the stream crossings. Reviewing the crossings between
KM and VVR in my mind, I thought not. I advised them to press on. [With
crampons 100% snow is better than mixed ground] I also advised Ski
Mountaineer's Pass. The current snow melt forcase is dated 5/18. The new
forcase should provide much better info on snow melt and river volumes.

Per my prediction, VVR is closed. VVR claims that they will snow mobile in
and be available for thru hikers. If not, they need to hike out over
Kearsarge. I agreed to determine the status of the Kearsarge Pass and
Mammoth roads this weekend. If necessary I will drive to Kearsarge to supply
them next week.

Snow on the UTY snow pillar is still 39". However, temperatures have been
well above freezing 1/2 the day. The high altitude melt should start soon.

Tom

-----Original Message-----
From: Reynolds, WT 
Sent: Thursday, May 05, 2005 11:27 AM
To: 'dsaufley@sprynet.com'; 'The Weathercarrot'; Reynolds, WT;
'pct-l@mailman.backcountry.net'
Subject: RE: [pct-l] snow comparisons

Donna's question will take some research. I can, however, answer The
Weathercarrot

The process I use compares the snow on the UTY snow pillar for various
years. Both Greg and I use this indicator necause it is the best indicator
of the snow accumulation in the high southern passes. The second best
indicator IMHO is Bishop Pass. 

On April 1, what I did was pick snow years where there was considerable snow
at this location. They, in fact corresponded with the high snow years that
you indicated. I then graphed the melt on UTY using data on 3/1, 4/1, 5/1,
6/1 and 7/1. My conclusion on April 1 was that there was generally zero melt
between April1 and May 1. Only in 1997 did an April melt occur in a big snow
year. In every other year a slower than normal melt followed a big snow
year.

On May 1, I checked the actual UTY [and other] snow pillars and found that
my April 1 analysis was correct. There had been zero melt on UTY. In fact
the temperature rarely reached freezing. At this point I threw out the 1997
early melt data and focused on the others. In all cases the slop of the snow
melt after May 1 was less than normal. Using that data I predict the day
where there will be zero snow on the UTY snow pillar as July 12. In 1995
that date was July 11 and in 1998 it was July 24 according to my
predictions. Checking the historical record I find my predictions accurate
within a day.

After May 1 everything depends on the weather. I am now using "Forecast of
Runnoff Volumes" as my predictor of how fast the snow will melt.
Unfortunately I have only looked at this data since 1998. Using weather data
this report tries to predict when the peak melt will occur. The report is
updated every 5 days and uses the weather forcast to predict the melt for
the next 10 days. Let me say simply that this could be a very bad year.
Also, let me say that the southern mountains will continue to be daunting
because we are looking at cold, wet weather for the next 10 days and very
little melt is likely to occur.

To specifically answer The Weathercarrot's question, 2005 looks very much
like 1995 at this point. 

Date		05/05		06/01		07/01		UTY zero day
2005		40		
1995		39		31		11		7/12
1998		45		40		25		7/23
1983		65		57		35		7/23
1993		30		17		0		6/28