While I took a potshot at drawing lines on a temperature chart that looks more like a step pattern to me, it is valid to note the relationship among the 3 lines of La Nina, neutral and El Nino seasons.
1) the El Nino and La Nina lines are parallel and about 0.1C apart. So an average El Nino might be +0.05C warmer than whatever the average is for the current period. If it's "super" like 1997-98 maybe as much as +0.2C warmer.
Those are "world" temperatures. A local region where someone is skiing may be different. Nonetheless 0.05C is a very small number. The snowfall impacts that interest us on this thread are mainly caused by the jet stream being more often north and strong (La Nina) or south or split/weak (El Nino).
Here in SoCal we'll take our chances with El Nino being warmer than average and having some rain in the mountains along with the snow. The alternative is that it's dry and we get hardly anything, like the last couple of years.
For the La Nina favored regions (sibhusky and others who live there are free to contest this point) I think the converse is true. The El Nino years are drier and the La Nina years get more storms. For areas like Banff/Lake Louise winter rain is non-existent and they favor La Nina just as much as places like Whitefish that get some rain and Washington State areas that get a lot of rain. Maybe it's less obvious up there because "dry" in Whitefish means 200 inches instead of 300, while dry in SoCal means it's still fire season in January.
70F off Ventura and Santa Barbara this weekend. Amazing, but likely not relevant to the upcoming ski season. The warmest water I've experienced in SoCal was summer of 1971, probably related to L.A. setting a record for consecutive days over 90F. And what was 1971-72 ski season like? 160% in the PNW and 78% in California.
As most of you know, I think all of these months-ahead forecasts are complete BS, except when we have a moderate to strong El Nino/La Nina. And the best use of the latter is simply to assume that it will retain the status it has in July-September into our ski season because history says it tends to be stable during that timeframe.
I am thus skeptical that the Arizona/New Mexico/Colorado summer monsoon season is in any way predictive of the upcoming winter. The strongest El Nino summers were 1997, 1987, 1982, 1972, 1983 and 1993. Maybe someone can tell us if the monsoons were unusual during those summers.
The human mind tries to find patterns. In the case of weather most of them are random. Thus I'm also skeptical of the analog season theories. Summer 2014 being very similar to summer 19XX doesn't necessarily mean the upcoming winters are analogous.
For some who asked about 1999-2000, that was a mild La Nina season coming after a big La Nina, similar to 2011-12. However those 2 ski seasons were not that similar. in 1999-2000 only the Southwest was poor, all the other regions were between 91% and 111% and the overall average was 97%. In 2011-12 5 of my 8 regions were worse than the Southwest was in 1999-2000 and the overall average was 84%. The La Nina favored regions were average to above average in both seasons.
The mild El Nino seasons move the average expected snowfall but there are exception seasons. The US Northern Rockies were 125% in 1977-78 and 120% in 1994-95. I have not published percents for mild vs. moderate vs strong vs. "super" El Nino seasons because there really isn't enough data to draw conclusions at that fine a level.
Edited by Tony Crocker - 7/23/14 at 10:07pm