2019- 2020 NORTHEAST WINTER OUTLOOK
Most everyone has heard of El Nino and La Nina, especially when talking about the winter outlook. This is refered to as ENSO (El Nino Southern Oscillation) There are other "oscillations" in the atmosphere that affect our weather. However, ENSO is the only one that is linked to the ocean temperatures. This is important for two reasons. First, there is a lot of skill forecasting our ocean temperatures. Second, the ocean temperatures don't suddenly change. These two facts allow us to predict the atmosphere several months into the future. Most of the other oscillations are purely atmospheric. As such, they can only be predicted 1-2 weeks into the future with any skill making these oscillations much less predictable, the result is blindsiding a forecast by altering or even overriding the effects of ENSO.
All that being said this Outlook will lean on ENSO just the same.... what is the state of ENSO.
It's looking like we end up in a Neutral ENSO this year..This means La Nada no El Nino and no La Nina..The result here is shown on the map below for what Neutral conditions are likely to bring over the winter.
Now that we got ENSO clear and out of the way lets take a look at SSTs (OCEAN TEMPERATURES) and how well current SSTs match up to past winters..the best overall match I could come up with was the winters 2013 and 2014. Both winters showed very warm SSTs and strong High Pressure in the Gulf of Alaska. As seen in the top map Neutral winters do tend to favor a colder Northeast.
So we have the cold, what about the snow? This is a bit more tricky as the analog years I've looked at do match, they aren't as clear cut as I would like them to be, the displacement of warmer SSTs are a bit more west rather than tucked closer to the west coast. This could help to keep the Winter Trof in the Central part of the USA which would allow a SE Ridge to Develop aiding in more Cutters early in December than coastal storms, But as we approach the later part of December leading up to Christmas things should turn wintry as the the storm track shifts to a more coastal Benchmark theme.
What I do know is we will see an active southern jet stream and increased moisture flow across the southern US. Meanwhile, frequent energetic disturbances will be favored along the northern stream due to the arctic outbreaks in the Central US..this is already taking shape as the last few storms were coastal systems with some Tropical assist and Jet stream Phasing.
These two active jets will provide a higher likelihood of phasing of the two branches which may lead to multiple threats from nor'easters in the East. Snow lovers may not have to wait long either, with these coastal threats more favored toward the end of December. While snowy patterns will still be around into January and February, the axis of more frequent snow will gradually expand into the Mid Atlantic States as well.
SST's MAP OCEAN TEMPERATURES
CLOSER TO THE COAST
JUST OFF THE COAST
NOTE THE WARMER WATER IS FURTHER WEST THAN IN 2014
Now the Million Dollar question is "What will the winter be like?"
As it looks right now A combination of favorable atmospheric and oceanic circulation patterns along with support from several analogs of similar years indicate that a more active storm track will be the rule this year. This combination could set the stage for several big winter storm events up and down the East Coast, especially from late January into most of February.
We all remember the 2014 record setting winter with seemingly endless piles of snow. I stayed up around the clock creating Storm Maps and as major Northeast cities accumulated a snowfall surplus of 15 - 30+ inches. In fact, Philadelphia recorded their 2nd snowiest winter of all time with 68.0" and New York's Central Park finished with 57.4", the 5th snowiest. Along with the snow, frigid temperatures dominated with places like Hartford CT seeing 44 days of at or below freezing temperatures. Coming off such a brutal winter, will this winter analog bring back the onslaught of cold and snow or will a milder winter be the rule?
Well for those looking for a balmy winter, you're out of luck. While October may have been rather mild overall, the main theme for 2019-20 will be seasonal cold.
I even looked deeper this year and found that almost all of the past winters with similar characteristics to the expected pattern this year have featured Seasonal cold. These years include 1976-77, 1977-78, and 1993-94.