George001

An entire seasons worth of snow in one storm, a blizzard of that magnitude would be the most severe blizzard on record. If you take the most severe blizzard I have ever experienced in my life (Feb 2013) and double that, you get a 48-60 inch blizzard. That seems like it would be extremely difficult to do, maybe if you get the early Jan 2018 blizzard (about 14-18 inches eastern mass) with severe North Atlantic blocking to slow it down. The strength of that low got all the way down to the 950 mb, but due to the lack of North Atlantic blocking it didn’t really stall much. Just 2 months later we had a slightly “weaker” low come up the coast in the 960s, yet I ended up with 2 feet of snow from that blizzard. Some areas got close to 3 feet. Imagine if we got a rapidly strengthening 930s mb low that just sat there right over the cape, if we get that I don’t think it’s out of the question that my area ends up getting enough snow that it piles up over my head from that blizzard alone.

I think it is very possible we see North Atlantic blocking the entire winter, and even if we don’t there is a good chance we get severe polar vortex intrusions to offset that, as the polar vortex is looking weak on the models.

Great write up, I hope it’s wrong in my area but it looks to me like many of your analogs have a trough in the west, which is a legitimate concern. I had some similar analogs (I had 2017-2018 and 2020-2021) but I am learning towards well above average snowfall in my area rather than 87% of normal like yours. It very well could just be me having weenie goggles on, but I did see several of the models saying the polar vortex would be weak and displaced, so I am thinking that could tilt things in our favor some. Just wondering, for that 87% figure are you thinking a more boom or bust winter with a slight lean towards the bust side (hence the 2001-2002 analog), or is it less bust potential and more of a limited ceiling that brought you to forecast slightly below avg snow for my area?

I agree, the acceleration of climate change is making our winters warmer. I never saw 70s and even 80s in Feb and March until a few years ago. Snow wise we haven’t started declining yet, but the mid Atlantic has and as the average temperature continues to increase, in my opinion our snow average will decrease as well. There comes a point where the increased upside due to the clashing of a cold airmass with climate change induced warm ocean temps isn’t enough to make up for all the marginal events that would have been snow 20 years ago being rain today. Even in the last 10 years it feels like it’s harder to maintain a snowpack than it was then, even in our above average winters like 2018.

I don’t see a trough in the west and despite the lack of North Atlantic blocking it does look like the model is indicating a severe polar vortex intrusion into the eastern United States. For a mean that’s not bad, could be 2 good months 1 bad like 2017-2018. Idk if I’m reading it wrong but it looks like there is a weak El Niño in the Enzo region which is strange.

Over recent weeks, the strength of the upcoming La Niña has increased on the models. There is still a decent spread with the CFS going borderline strong where as the European model is going with a weak La Niña. What ends up happening will likely be somewhere in the middle based on what I have been looking at in my opinion. More importantly, the entire Pacific Ocean is cooling off and the models are forecasting a weak and displaced polar vortex, with several intrusions into the eastern United States. Moderate La Niña, severe polar vortex intrusions into the eastern United States, North Atlantic blocking, and a weakened pacific jet is what I am thinking we get for the winter pattern at least the 1st half of winter. Often in the second half of La Niña winters they start to suck on the eastern us because the La Niña weakens and it’s grip on the pattern starts to loosen. This allows the pacific jet to start acting up with limited northern branch interaction due to a stronger and more consolidated polar vortex parked right over the North Pole. In my opinion the floor for this winter is 40 inches in the Boston area, with the strength of the La Niña and the polar vortex being the deciding factors on whether winter peters out early like last year, or whether it goes deep into March with multiple severe blizzards during the back half of winter. The range of outcomes I would say is last year as the floor and 1995-1996 as the ceiling, with 2017-2018 being a most likely middle ground.

La Niña probably won’t be strong like I originally thought though since the ocean warmed after cooling to -.9, it’s only -.3 right now and most strong ninas are already at least moderate strength by now. For the 2010-2011 extreme La Niña event the Nina was already strong by this time in the fall of 2010. With the newest data I’d lean low end moderate rather than strong due to the current surface temperatures in the Enso region.

Latest cfsv2 data moved towards a stronger La Niña. The mean is around the same strength as last year.

That look decent for December but not 2010-2011 like, all that red off the west coast scares me a bit. That tells me that there is a signal for a strong pacific jet as well as a powerful and energized Hadley cell. I don’t really know a lot of Hadley cells but based on what I do know they are not good. I would like to see the Pacific Ocean as a whole cool off to keep the Hadley cell in check. Don’t get me wrong I don’t think that’s a terrible look even with the rough February but it doesn’t scream epic winter, more like an average winter like last year, with the potential being capped due to the expansive Hadley cell. We have had 6 straight winters with an expansive Hadley cell, and I’ll start getting excited for an epic winter when I see signs that the dominance of the Hadley cell this winter won’t be there like it was the last 6.

It is? I thought the trough out west was bad. Even Metfan starts to panic when he sees a trough in the west. When Metfan is panicking that’s usually not a good sign, as like me and James (rip) he has snow goggles and tends to be too aggressive with his forecasts. My concern is that with the trough in the west and the strong pacific jet that the pattern would be really zonal, with ceiling being a 6-12 inch storm if everything lines up. I am looking for a severe winter with at least 3-4 massive blizzards like 2010-2011, 2014-2015, ect.

Hopefully the strength of the La Niña continues to increase. The entire Pacific Ocean is too warm and we need a decent strength nina to cool it off, limiting the pacific Jets ability to strengthen. The good news is that in the most recent update of the cfsv2 model, there is much less spread than even just a couple weeks ago. This indicates that the picture of what the Enso state will look like in the winter is becoming more clear, with the cluster being narrowed from -.5 to -1.8/-2.0 to -.8 to -1.3, with the mean being right -1.1, a low end moderate. The subsurface also indicates that the structure of the la nina could shift from a western based Nina to a basin wide or even a more eastern based la nina. A high end weak or low end moderate basin wide or east based La Niña would be very favorable for New England blizzards, so hopefully the models are right about that.

Yikes that’s not a good look. That ridge in the northern Pacific Ocean is way too far west. It does look like there is a signal for a polar vortex event, but with the polar vortex intrusion being west like last year. North Atlantic blocking is also limited, which combined with the awful pacific would be a disaster.

I do think there will be a La Niña but I agree that the pacific won’t be all that great this winter. There is too much warmth in the Pacific Ocean right now, and I don’t see that going away completely this winter. However I don’t think it will be anywhere near as bad as last winter, and in my opinion we will likely have severe North Atlantic blocking as well as several polar vortex intrusions. In New England we are probably good for at least 3-4 severe blizzards this winter, unlike last winter where we only had one (2 in most areas, that early feb one I got skunked, only 8-9 inches while 15-20 miles NW got 18+ inches).

Right now my call is -1.6 ONI peak for this La Niña. I am very confident that there will be a La Niña, less so of the strength. My current thoughts are: Super La Niña: 14% strong La Niña: 35% moderate La Niña: 30% weak La Niña: 20% cool neutral: <1% warm neutral: 0% Weak el nino: 0% moderate El Niño: 0% strong El Niño: 0% super El Niño: 0% What would your guys predictions look like in terms of percentages and ONI peak? For mine one thing to note is I wouldn’t say anything is completely 0, but the odds that we get an El Niño this winter in my opinion are lower than the odds of me getting struck and killed by a giant meteor tomorrow.

Yeah I was not aware of the cdc using a different baseline than the models, that explains why the models appear to underestimate the strength of la ninas. I see what’s going on now, the models aren’t actually underestimating the strength of la ninas consistently, just using a different baseline.

I am leaning towards a moderate or strong La Niña but this is definitely something to consider. The models have underestimated the strength of la ninas historically, if on average they underestimated the strength of the La Niña by .25 then taking that into account that puts us right at -.8, which is the strength of the 2017-2018 weak La Niña winter. For me, I have been keeping track of the cfsv2 model and paying attention to the trend as well as what the forecast is. Looks like it’s expecting the Nina to peak in the fall at -.1, right on the border of weak/moderate. However, the spread is still very wide, from .5 to -2, with most of the members being -.5 and -1.5. However, there are more outliers in the -2 range than the .5 range, and even more telling is that all of the blue line outliers are towards the lower end of the envelope. This suggests to me that even though a -.8 to -.9 is the forecast right now, if this ends up busting, it’s likely going to be busting warm. 7/8 of the most recent forecast members take the La Niña to -1 or below, solidly moderate. What really tilts this in favor of a stronger Nina for me is that this update of the cfsv2 model is that the members haven’t even ran yet after the drastic drop in temps from -.4 to -.9. Once it does, I wouldn’t be surprised to see the mean drop from -1 to -1.2 to -1.3, possibly even lower.

Over the past week, the strength of the La Niña has drastically increased. After the development of La Niña stalled out for a bit, we have more than made up for that lost ground with the Enso 3.4 region dropping from -.4 to -.9 degrees Celsius, which is already borderline moderate La Niña conditions. To put this into perspective, right now the enso 3.4 region is cooler than the last CFSv2 runs mean peak for the entire winter, which was -.8. Another thing to note is that if you look at the blue members, which are the most recent forecast members, all of them are below the mean of -.8. This suggests that the strength of the La Niña is being underestimated by quite a bit on the models. At this point, the question isn’t whether or not we get cold neutral or weak La Niña, but whether we get a weak-borderline moderate La Niña at -.8 to -.9 and it stalls out (possible if the subsurface doesn’t keep cooling off, it has stalled in recent weeks), or it keeps strengthening and we get a 2010-2011 redux (-1.6 peak, -2.4 MEI. Extremely strong La Niña).

True, It doesn’t mean good winter at all, but it increases the chances of North Atlantic blocking in my opinion. The issue is the entire pacific is just too warm, which fuels the pacific jet to strengthen rapidly. We have had North Atlantic blocking and had bad winters anyways several times. Sometimes blocking can be bad too if you have a moderate or stronger El Niño, then everything misses to the south like 2009-2010 (in general). I would rather see signs favorable for blocking with a La Niña coming up than an El Niño. In 2014-2015 if I remember correctly the solar activity was high, and we had little to no North Atlantic blocking that winter. Yet that was the snowiest winter on record in southern New England.

-.9 already? WOW. That is already borderline moderate strength and summer hasn’t even ended yet. It looked like the La Niña was slowing down for a couple of weeks but we made up that lost ground fast. 2010 sticks out like a sore thumb when looking at the similar ONI and SOI readings by late August. When looking at both the ONI and SOI and comparing similar readings, more strong la ninas show up than weak ones.

In 2010-2011 the solar was on the lower side but on the rise like this year, and the geomagnetic activity was very low. This winter will be similar in that area but you bring up a good point about the Enso state of the previous winter. The enso state the previous winter in 2010 was strong El Niño, the previous enso state last year was moderate La Niña. That is the exact opposite which is not ideal for an analog. I have read on Isotherms blog, in the forecast for the 2010-2011 winter he mentioned the geomagnetic activity has a much stronger correlation with North Atlantic blocking than the QBO (Isotherm, if I misinterpreted or misunderstood what you wrote, feel free to correct this). I thought the QBO was more correlated with the polar vortex than north atlantic blocking, with positive QBO being correlated to lower chances of a severe polar vortex event. My understanding of the QBO and polar vortex is low so that may be an oversimplification, but that is what I got out of the reading I did on it.

The low is not going to go out to sea. It is moving due north right now, if it were going out to sea you would already see signs of the low slipping to the east, but that isn’t happening. An eye is forming which suggests the strength of the low is also increasing.

It’s definitely not good with the blob of warmth in the pacific right off the west coast being too far west. I don’t like seeing that, but at least the rest of the pacific is more mixed of warm and cool anomalies rather than the entire thing being on fire like last year (other than the Enzo region). Correct me if I’m wrong, but wasn’t last years even worse? If I had to give it a rating on a 1-10 with 1 being terrible and 10 being great, I would give last years a 1.5, this years pacific a 4, and 2010-2011 a 9. How would you rate the pacific sst in terms of how favorable it is for winter in those 3 years?

Wasnt 2010-2011 strong Nina not moderate? The oni peaked at -1.6, which is strong. The MEI peaked at -2.4 in the fall, going by that the 2010-2011 is a super Nina. Either way when taking both ONI and MEI into account it was a strong La Niña that was dominating the pattern for the entire winter.

I already told my family there is going to be a massive hurricane headed for us. With a storm like this id rather be overprepared than underprepared. I noticed that some posters here aren’t really taking the storm that seriously, which I kinda get because the low doesn’t look all that strong on the models. If anyone is planning on going on like normal with their plans tomorrow, I strongly recommend reconsidering, even if it’s unlikely you do not want to get stuck driving home in the middle of a stronger than expected category 2 hurricane. I am aware that is not the forecast right now, but with how the storm looks right now the possibly that it strengthens more than expected is there. I hope it doesn’t get that strong because I’m not a big fan of hurricanes like I am blizzards, but I just can’t see how this ends up being weaker than expected looking at the storm right now.

That looks extremely powerful. When you see an eye like that it’s a sign that the low is going to strengthen more than expected. I have never in my life seen a storm with an eye end up being weaker than expected. In my opinion the models will start increasing the strength of the low.