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[pct-l] Low snow cover to date

Very interesting Greg.

I assume that you are using the Tyndall Creek station. If so, I have also
studied that snow pillow relative to how much snow is on the trail to
Forrester Pass relative to the date the snow pillow clears. The delay is
typically two weeks meaning, two weeks after there is NO snow on the Tyndall
Creek snow pillow the trail up to Forrester will only have snow in a couple
of places-typically the chute the trail crosses just below the pass.

My VERY CONSERVATIVE rule of thumb for my 2002 hike is leave KM when the
Tyndall Creek pillow reads zero. {I hates snow and have no clue how to use
an ice axe]
-----Original Message-----
From: Bighummel@aol.com [mailto:Bighummel@aol.com]
Sent: Wednesday, January 31, 2001 6:01 PM
To: pct-l@mailman.backcountry.net
Subject: Re: [pct-l] Low snow cover to date

I haven't had a chance to check out the snow survey sites recently, however,

from historical data here are some general rules of thumb (with a big margin

of error!) that I have drawn from data for 1999 back to 1972.  I presented 
this to the list last year and received no response, so I must assume either

everyone agreed with my analysis or everyone thought I am truly losing it!

The earliest that historical records report snow levels is in the month of 
February.  I compared these records with the amount recorded on the last 
month recorded; May. I looked at the information from the Bighorn Plateau 
survey station (11,350') which is just south of Forrester Pass and a good 
general indication of the amount of snow at high levels in the Sierra 

I divided the snow pack levels left over from the winter months (recorded in

May) into three general categories; light, average and heavy (many 

I looked at whether the snow pack tended to show up early or late on each of

these and found that typically (assumption), light in Feb. means light in 
May, with a few exceptions of late storms.  In other words, late snow storms

don't often make up for a light snow pack in Feb.  In only one year, 1975, 
has light snow in Feb. led to more than light (average or heavy) snow pack

In "average" years nearly all had most of the snow pack fall in Feb. In
words, average snow pack in February means an average snow pack overall.  In

only three years did an average snow pack in Feb. mean a heavy pack in May.

In "heavy" years the snow fall mostly started off heavy.  In only two years 
did heavy snow pack in February melt off to average levels in May.  However,

in two other years, average snow pack in Feb. led to heavy in May.

Therefore, roughly (assumptions abound here) and assuming normal melt off 
conditions from May into June:

1. When there is less than 40 inches of snow depth in Feb., then expect 
approximately 14 inches in June when you would be going thru, for a "light" 

2. When there is more than 40 inches and less than about 70 inches of snow 
recorded in Feb. then expect approximately 26 inches in June, for an 
"average" year.  

3. When more than about 70 inches are recorded in Feb. delay your trip start

date so that you hit the high Sierra in July, OR seriously consider a North 
to South trip, as you can expect more than 80 inches still sitting around in


Oh, and 1977 is the lightest year on record in this time frame, the year I 
hiked the PCT.  The record shows 2.9 inches in May.  I know this to be true 
as I stayed in the snow survey cabin one night in May that year with what I 
would call "approximately 3 inches of snow on the ground".  I stayed in the 
cabin because the temperature dropped to about 5 below zero that night.  It 
offered shelter from the cold so I accepted.  

I hope this is useful for planning purposes at this time when many of you
looking for some indication of what kind of winter this will be and therefor

how should my schedule fall.  Good luck, 2001, a PCT odyssey!

So, check the snow survey records for the Bighorn Plateau in February and 
make your best guess!

Best regards,

Greg "Strider" Hummel
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