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[pct-l] Year to year snow levels/early start



>Jennifer wrote:

>>Also, does anyone know the earliest time that someone has left from Campo
>>and been successful in through hiking without layovers waiting for the
>>snow to melt??

Before Jardine, most people left sometime in early April, but it depends
greatly on the year.

In terms of 30-year averages, California is deep in the middle of a 15-year
drought spell, with another 15 to go. As these major climatic swings begin,
the weather can be extremely variable--going from 60% of normal (1976-77)
to 200% of normal (1978).  So far, we are dead on in terms of historic
drought patterns--most years about 80% below the 100-year state-wide
average (where known), with the oddball year like 2 years ago where we were
well over 100% of normal.

People who took their trips in the early to mid-70s experienced the tail
end of California's "good water" years.  People in the 80's experienced
true drought conditions, except for the oddball year(s) when the skies
opened up for months on end.(and there are a number of experts who think
that the only reason it rained was because of the volcanic eruptions in the
previous year.)  In the 90s, so far its been mostly drought statewide--2
years of decent rain, and 5 years of dryness.

Regional variation from the statewide pattern also play a part.  For
instance, So. Cal had 2 years in a row of normal rainfall due to some
unusual monsoon patterns, while the rest of the state was still in the
drought doldrums in the early 90's.

Conversely, last year the state as a whole was near normal, but from the
San Jacintos south to the border was below normal. This year, the southern
Sierra had 101% of normal, while the state is at 81%.

So, what does all this blathering have to do with start dates?
--------------------------------------------------------------
I'm not a big fan of Jardine's schedules, because each of his 3 hikes were
technically all in good to great water years. Specifically, his first hike
was during a year that turned out to be a state-wide drought year  BUT, the
previous 2 (and possibly 3--memory fails me at this point) years in So Cal
were at or a little above normal.  So even though the Jardines experienced
the heat, they did not experience the lack of water that usually
accompanies a drought year.

(Most of the desert water sources are fed by underground acquifers, not by
meltwater or run-off. Several years in a row of average rain will keep the
springs running for a year or two into a drought.)

It sounds like this year's class is experiencing what I consider to be far
more "normal" conditions for the state. I am very interested in finding out
how they're faring and if they would recommend a late April/early May start
dates to others.

In normal to above normal years, Jardines's schedules should work well,
providing you plan to hike his mileage averages.  If you prefer to hike at
a slower pace, I consider his schedules downright dangerous, since they
theoretically have a hiker go 30+mile stretches without *permanent*
water.(and if you're a 10-mile a day hiker, that's a lot of water to
carry.)

In conclusion
--------------------
I think the question to ask is how far you want to hike in a day, how much
does snow factor into you're thinking, how much heat you can tolerate, and
how much water you're willing to carry.

Personally, I also consider when the desert wildflower season will begin
that year.

The other thing I recommend is taking a look at the state's meterological
data, especially the 30-year averages.  I don't believe the data is online
yet, but a reference librarian should know where to find them. (Most
university libraries carry the books, and they used to be available from
the USGS.)

And oh yes, the earliest successful thru-hike I know of personally is two
fellows who left March 31.  They left in a "normal" snow year, and used
crampons and snowshoes in parts of the southern sierra.

Sorry for the length of this post--I obviously need to get outside!

Catherine (Geographer by training, climatologist by avocation, tech writer
of necessity)


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