Winter Forecast: 2011-2012

So, let's start by noting that winter forecasts are generally bunk (well, mine are, at least :P ). But I like coming up with a guess anyway.

My methodology? Very simplistic and probably worthless. I looked at northern hemisphere 500hPa anomalies for August and September and compared them with previous years. I found "analog" years that fit both months reasonably well, with more weighting given to years that fit better. It was completely qualitative and subject to my biases, whatever those may be.

I then checked the analog years for ENSO conditions. This winter will almost certainly be a Nina winter. So, I subtracted one "weight" for years that were Nino, left the "weight" the same for years that were Neutral, and added one "weight" for years that were Nina.

My final analog list was:
1950; 1950; 1950; 1960; 1962; 1962; 1966; 1966; 1966; 1979; 2001; 2001; 2009

Repeated years are years with more weight given them.


Given that list of analogs, I looked at the 500hPa pattern for each "extended winter" month (Nov - Mar), and drew a map of what I'd guess would be the corresponding temperature anomalies. Here they are:

NOVEMBER

DECEMBER

JANUARY 

FEBRUARY

MARCH

The key is...
Red: Torch
Orange: Warm
Yellow: Mild
White: Near normal
Blue: Cool
Purple: Cold
Lavender: Frigid

As for precipitation, I'd say overall winter precip would be well above normal in the Pacific Northwest, and below normal from Southern California through Western Texas. Elsewhere, it'll probably balance out to near normal overall.