Yes, it’s early to be thinking about what Winter 2014-15 may hold for us. But don’t let that stop us from having some fun!
The Pacific Ocean is a vast heat reservoir. Remember that water has high specific heat capacity, meaning that it takes a long time to heat up and cool down. The larger the the pool of water, the longer it takes to heat up and cool down.
The reason I like to look at the Pacific Ocean is because there is no larger pool of water and it is one of our dominant upstream weather sources.
Looking at the Pacific picture:
Two things really stand out here:
- Massive PDO+ manifested by large pool of warm water over Gulf of Alaska
- Developing ENSO+ (El Niño) with warm equatorial waters off South America
PDO+ was a dominant feature of last winter, which resulted in a mild winter for the western USA and Alaska. This enabled the jet stream to buckle and deliver frequent blasts of Arctic Air into southern Canada into the northeast USA directly from Siberia. If PDO+ persists through autumn into the winter, that could bode very well for a cold and snowy winter here.
El Niño, on the other hand, is a tricky beast for us. Strong El Niño’s, like 1982-83 and 1997-98 are no good for us. The subtropical jet stream gets on steroids and keeps the cold air confined way up north in the Arctic. Most of the significant storms in a strong El Niño winter result in rain and ice, rather than snow.
On the other hand, a weak to moderate El Niño may not be a bad thing for us. In these weaker El Niño instances, the subtropical jet stream is strong enough to add a kick to developing Nor’easter storms, but they don’t overwhelm the Siberia to northeast USA connection.
The ensembles are clustering toward a weak/moderate El Niño (0.5*C – 1.0*C anomaly) peaking in late fall/early winter, then declining over the course of Winter 2014-15. If this turns out to be the case, then I’m not that worried about big, bad El Niño:
Golden Gate Weather Services has a really neat El Niño/La Niña table and chart that goes all the way back to 1950. It’s too big for me to transcribe onto this post, so check it out here:
http://ggweather.com/enso/oni.htm
Bottom Line:
I see a couple of things that encourage me: PDO+ and the forecast weak/moderate El Niño for Winter 2014-15. But until we can see how the Siberian snow pack spreads into Eurasia in October and how the Arctic/North Atlantic Oscillations trend in the fall, I don’t have enough pieces of the puzzle to make the so called “Winter Outlook.”
If you have seen any early winter outlooks, share them in the comments section and we can have a good laugh together.
For the ilsnow nation,
Darrin
