[pct-l] El Nino Gossip

[Bighummel@xxxxxxx (Bighummel@xxxxxxx)]

Tom Reynolds and I make educated guesses on the eventual meltoff -
passibillity date for the High Sierra each year on about February 1st.  I
think that I paid him a 6 pack last year for his date was closer than mine.

If you want to do what I do and keep up on the snowpack in the Sierras, then
go to
http://cdec.water.ca.gov/snow/ and click on the "Snowpack" link.  A good
indicator of the passibility of the High Sierras is the Kern River Basin as
the snow surveys there closely follow the PCT and are indicative of how much
snow might be around Forrester Pass.  By February 1st you can make a guess.
Generally by March 1st you can make a pretty damn good guess.

Right now, with several early "El Nino" storms having gone through AND
unusually warm weather, the surveys show generally less than a foot of snow
in the Sth Sierra with a bit more at higher elevations.  (If this was the
case on May 15th, I would proceed from Kennedy Meadows, YMMV.)  However,
about 135% of the normal precipitation to date has fallen.  Thus, a lot of
snow has fallen and a lot has melted and not stayed.

What does all of this mean historically?  There is no "typical" El Nino year.
 "El Nino" means to southern California and the Sierras erratic weather and
heavier than normal precipitation.  That might mean more snow in the Sierras
and it might mean more rain than snow.  What the thru-hiker is normally
concerned with is when will the snow meltoff start?  This depends upon
whether or not late Spring storms bring  cold snow.

>From analysis of the historical records of the highest elevation snow survey
near Forrester Pass (Bighorn Plateau at 11,350'):

- You have > 80% chance in ANY year, regardless of early snow, of not getting
late Spring storms that dump significant snow.  Recognize that El Nino years
may be in the 20% where you do get late Spring storms.

- The average snow depth at March 1st is 55 inches.

- When LESS than 55 inches;
       - Nearly 50/50 chance of an early meltoff (= < 20 inches on May 1)
       - Only 23% chance of a late storm keeping snow pack deep (= > 40
inches on May 1)

- When more than 55 inches;
       - 75% chance of a late meltoff (= > 50 inches on May 1)
       - 31% chance of getting a late storm (more snow in May than March!)

70% of late storms hit in heavy snow years.

Overall there is a 20% chance of it being a light snow year AND it melting
off early WITH no late storms.

If you are not confused by all of this then I hope it helps you to make some
decisions.  However, making any decisions now based upon what might happen in
the next two months in the High Sierra is fruitless, IMHO.

I accept no liability for any fool who follows any of my advice or opinions.
After all I followed my opinions and got myself into a heep of trouble! ;-)

Best regards,

Greg