Winter Outlook 2013-14
First of all, let me say up front, that this involved a lot of guesswork. Way more than your basic 48 hour forecast.
All we are looking for here is trends, and how the winter will compare to normal. I would not make any financial or personal decisions based on this outlook. I have professional meteorology friends who spend way, way more time on this type of forecasting, as there is big money to be made if you can crack the atmospheric code.
As I have alluded to in previous years, I am indebted to their work to clue me in on some of their forecasting techniques.
For purposes here, winter is defined as meteorological winter: the months of December, January, and February.
I looked at years in the past where the stratospheric wind patters were similar to what we are seeing right now, we refer to that as the quasi-biennial oscillation, or QBO.
I also looked at years where the El Niño/Southern Oscillation (ENSO) pattern was similar.
I tried to correlate those past events with current snow cover in the higher latitudes of the northern hemisphere during the middle to late autumn.
At present, the QBO is highly positive, but decreasing.
Additionally, the current level of ENSO is close to neutral, and most forecasts suggest it will stay neutral or go slightly positive during the winter.
Snowpack is currently a little above average in eastern Canada.
I went back about 50 years to look at similar QBO and ENSO parameters, and found the best analogy to be the winter of 1969-70.
I also briefly looked at the Pacific Decadal Oscillation (PDO). Like in 1969, we are in the midst of a long term negative phase. However, in 1969-70, there was a brief positive hiccup during the winter. Right or wrong, I am going with the long-term phase here.
The North Atlantic Oscillation (NAO) and its larger cousin, the Arctic Oscillation (AO), have dramatic correlations to storm track on the East Coast during the winter. And there are studies suggesting significant correlations between the QBO and the NAO. Given the QBO is a larger scale process (in time and space), I used that index as an implicit forecast driver of the NAO.
Pictured is the temperature anomaly for the winter of 1969-70. It was cold.
However, it was not particularly snowy. The overall trend in the central East Coast states was toward normal precipitation.
Hidden in that map, Lynchburg had less than 3 inches of liquid equivalent precipitation for the entire winter, dramatically below the normal of 9.26 inches. Most of what did fall came down in December. January had only 0.34 inches, February had only 0.52 inches.
So we are going with the idea of a colder and less snowy than average winter.
In a normal year, the average temperature for the entire season (high and lows averaged out) is 38. I'll guess that falls between 35-37 this winter.
For reference, last winter (2012-13) had an average temperature of 40. The cold and snowy winter of 2009-10 had an average temperature of 33.
Average snowfall is 17 inches. I'll guess between 6-10 inches.
But don't bet any money on it.