Winter Forecast -- Updated

October can be a very helpful month in determining what the winter might do. I looked at this October's 500hPa pattern and qualitatively came up with the following October analogs:
1948, 1948, 1950, 1953, 1955, 1956, 1957, 1958, 1962, 1962, 1963, 1963, 1964, 1967, 1977, 1979, 1980, 1989, 2005, 2007

Years that are listed twice were stronger analogs. Based on this list and the previous list of analogs I had already compiled, here is the updated "winter analog list" (for comparison, the old list is listed below)
1948; 1950; 1950; 1950; 1962; 1962; 1962; 1963; 1966; 1966; 1979; 2001
 (1950; 1950; 1950; 1960; 1962; 1962; 1966; 1966; 1966; 1979; 2001; 2001; 2009)

Again, the more a year is listed, the more it's weighted as an analog. Based on this "new" analog list, changes aren't actually that major... which gives me more confidence in the forecast. That being said, the November forecast seems to not jive with the two-week forecasts for the first half of November... so maybe the second half of November will overpower the first half? Anyway, here are the maps.

NOVEMBER

DECEMBER

JANUARY

FEBRUARY

MARCH

 

October 29th snow in State College - time lapse

Out my window:

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. 

I'm in Pennsylvania now...

... for grad school (Penn State University). But I'll still update this blog for interesting weather events in both the Pac NW and central PA this winter.

I've been pretty lazy with it recently (no posts on the severe wx or hurricane? For shame). But I'll try to be better about it in the future!

Not that anyone reads it. :P