Forecasts, updates and a little local perspective.
The Mid-Atlantic has a lot of factors because of the proximity to the Atlantic Ocean, Mountains, and even the Great Lakes. I want to outline the impacts of these AND the Pacific which will all impact this winter, especially early in the year!
The Atlantic Ocean is currently much warmer than normal. I think this will impact us in several ways:
There is often a cold pool off the Northeastern United States that is linked, many times, to a better negative NAO (See previous posts for information on the NAO)
You would not think the Great Lakes would have too much impact on our weather, but it really does! The Great Lakes can provide additional moisture to some storm systems, and, if it is warm, it can help moderate temps that are being impacted by winds that go across them. I am not saying this is a huge factor, but it does have an impact.
Probably one of the worst looks I have seen in a long while. The colder weather will encourage cold storms and the Jet Stream to be in a poor setup for us. I will discuss the Pacific Decadal Oscillation, the Pacific North American weather patterns, and the Eastern Pacific Oscillation in a post soon. All I can say is the pattern will favor milder terms for us and drier than normal conditions. I just do not like it.
Of course, we also have La Nina which will not bode well for big storms.
Most of the ocean looks terrible for us for winter. It is also the biggest signal that the winter may be warmer than normal and have less snow.
The Snow Advance Index is a feature that is not always the best indicator for how our winter will be. The basic principle is that the advancement of snow cover in October is closely linked to the phase of the North Atlantic Oscillation.
The North Atlantic Oscillation (NAO) measurement is a KEY FEATURE needed to help get snowstorms on the East Coast of the United States. For example, the NAO is currently negative, which helps to slow down and aid in the development of big Nor’easters like the one we are having this week (October 26 – 27, 2021)
Really, though, the negative NAO (NAO-) is not the key to these storms, it is as the NAO flips back and forth between the negative and positive (NAO+) that usually signals a storm
Anyways, when the Snow Advance Index shows a great increase, the NAO *COULD* end up being more negative for the winter.
So what is the Snow Advanced Index Looking Like?
The index is actually below where I would like to see it, but it is higher than last year!
The NAO Has been running Negative for a long while now. We will see if this can continue into November and Beyond! That would be a good sign for offsetting the La Nina impacts. (The line is below the 0)
Another factor for colder conditions is the Arctic Oscillation! As noted yesterday, when the Polar Vortex gets disrupted, it can turn negative! WE NEED THE NEGATIVE (if you like snow)! That is a better indication for more snow in the east! It has been running back and forth between positive and negative phases. We will see how this works out, but it looks like it is heading to negative again so the colder long-range seems to be linked to this as well! (Observed in black and red the various model predictions)
I am not super convinced we get non-stop help from the Arctic Oscillation this year, but I do expect a lot of variabilities which could help us at times be colder and have a chance of winter weather.
I do not think we have much to count on from the Snow Advanced Index, North Atlantic Oscillation, or Arctic Oscillation. The negative NAO has been encouraging, but that alone will not set us right for winter weather.