Preliminary Winter Forecast for 2012-2013 Season
Given that a winter weather advisory is in effect for the higher elevations of Colorado through Thursday, today seems like a good time to issue a preliminary winter forecast. Factors considered include ENSO, PDO, and AMO. These are not the only factors impacting winter weather, but these will serve as the basis for this forecast. As stated in my post “El Nino and the Upcoming Winter”, El Nino events during a negative PDO phase tend to be weaker and located in the central Pacific ocean. The effect of warmer than average water changes the upward motion pattern in the tropics. Air cools as it rises upward in the atmosphere and condenses in the form of cloud cover and rainfall. The jet stream then adjusts accordingly. Air flow is toward the central Pacific, as the air that rises needs to be replaced.
With that in mind, what are some years this upcoming winter appears to be similar to? I have weighted 1951-52, 1957-58, 1963-64, 1965-66, 2002-03, 2006-07, and 2009-10 highest because they follow Cold PDO/Warm AMO oncoming El Nino’s. Heres a look at the NOAA Physical Sciences Earth System Laboratory anomalies for those years blended together.
While this appears to be cool for much of the nation, let us not forget the United States was in a warming trend for much of the last 30 years. So lets check out the 1950-2007 anomalies
It should be noted that 1951-52 is a temperature outlier in the east.
We cannot toss out 1951-52 yet, but I prefer to blend the data at this junction. So here is what I expect for the United States for this winter.
Areas that usually get pounded with Lake Effect snowfall are in for a good year. The Great Lakes, especially the shallower lakes (Erie, Ontario) are very warm this year. It won’t take much for a good Arctic blast to drop copious amounts of snow in the Northeast Ohio, Western PA, and Western NY state. It looks like somewhere in the Northeast will really get hammered with snowfall this winter. It may be the Mid-Atlantic as it was in 2009-10, or New England (2002-2003). Some research suggests the sun plays an important role in the amount “blocking” that occurs in the high latitudes. Never the less there will be plenty of energy available off the east coast due to the warm phase of the AMO.
As of now I favor early snows for the Mid Atlantic before the brunt of the winter shifts north into New England. October temperatures have shown a correlation to the upcoming winter, so an update will be issued next month. These ideas are supported by the Japan Agency for Marine Earth Science and Technology (JAMSTEC) seasonal weather model.
- Surface temperature anomalies forecast
For specific questions about any given locations or any of this content, tweet me @zgreenwx or leave a comment and I will be happy to answer.