George001

What happened to the 80s this week? Just a couple days ago my weather app had temps in the low 80s Wednesday now it’s saying low 70s. Still well above avg this time of year but not record warmth like I thought we would get.

I agree with him on that. Latest enso forecast has the enso moving up to neutral before La Niña re emerges and peaks at roughly -.9 to -1.1 degrees Celsius (borderline weak/mod Nina). I have also read that there was severe volcanic activity last year, which often will have a lag effect where 2+ years out it will lead to extreme winter weather with severe cold and blizzard conditions. In 1816, the year without a summer it supposedly snowed in June in SNE, which is almost unheard of. Due to climate change, it is highly unlikely we will every see anything like that again, but it is very possible that due to the extreme volcanic activity last year the massive amounts of volcanic gases released into the atmosphere acting as a shield against solar radiation, allowing for cooler temps with an extended winter season and several severe blizzards. This extreme volcanic activity+ favorable Enso state has me leaning big as well, but things can change.

It appears the latest long range models support the nina ending in a month or two, transitioning to enso neutral and peaking at 0 degrees Celsius before dipping down again into another Nina (borderline of weak/moderate strength) for winter 2022. It’s still early spring so the models will continue to struggle with the Enso forecast, but we should know more by July or August. I’m rooting for this to be right, ninas of borderline weak/moderate strength tend to be great in eastern Mass, 1995-1996 and 2017-2018 were roughly that strength (96 a bit stronger, 18 a bit weaker). Ninas get an undeserved bad reputation from eastern mass snow weenies imo, yeah it means there will be more SE ridge but that isn’t necessarily bad, as it makes it less likely storms will miss to the south. The risk is more ptype issues, and I would rather deal with ptype issues than missing storms altogether to the south. It’s strange how eastern mass snow weenies panic and call for ratters when they see a big Nina going into the winter (like before this winter), yet we have roughly the same avg snow in strong ninas and enso neutral winters, and you don’t see all this panic about ratters when it’s enso neutral. The only enso states that have a strong signal for below avg snow are moderate nino and strong nino. Ninas are also better for snowpack retention, stretches of sustained cold, and frequent tracking for a bunch of moderate systems at the expense of a lesser shot at a huge one (due to less active southern jet).

The euro has had a strong low off the coast with a marginal airmass for a few straight runs. Eastern Mass is probably done due to climo, but CNE/NNE has a shot at experiencing blizzard conditions from that storm. In eastern Mass we tend to get screwed in late fall and early spring storms, even in a conductive setup for an early/late season snowstorm due to the mild ocean influence. Even the slightest east wind= rain since you are bringing in fall/spring warm Atlantic air. We need the winds to be due north or coming from the west or north west. One thing I learned from all these busted forecasts is especially when it isn’t mid winter (even then to a lesser extent), the wind direction cannot be ignored. I blame the ocean on why I got like 50 inches less snow this year than Worcester, I swear Worcester is a snow magnet, they always seem to not only get more than us in Eastern Mass but they even get more than some areas NW of there. Elevation+ being just inland enough to escape ocean influence (allows for higher ratio snows as well as more snow overall) but close enough to not get missed to the south from coastal storms that hit eastern mass helps a lot. I might be going to live there for college next year so I am looking forward to getting buried by multiple monster blizzards with high ratio snow piled up higher than i am tall. Hopefully we get a big nina again next year.

I strongly agree. It is late April so the probably of a snow event is unlikely, the pattern is as supportive as it can get for late April, and if things do come together when you combine an unseasonably cold airmass with warm spring ocean temps that would allow for rapid cyclogenesis. The warm ocean air is a double edged sword though, as it wouldn’t take much even with a monster slow moving ocean low to bring enough warm air in to screw over eastern mass and change us to rain. Due to this, areas that got hit the hardest by this storm would be favored again for the next one. I’m not going to call for totals yet but the euro would be one hell off storm.

After the mountains stole my 12+ inches of snow that I forecasted in the Boston-Providence corridor (I got .1 inches of snow), I thought this was it and we wouldn’t have another threat until November-December. However, I looked at the most recent Euro run and it appears it has a historic late April blizzard at hour 240. Looking at the upper level pattern and taking into account the fact that the Euro is the best long range model we have, this cannot be ignored and is a very realistic solution. There is a piece of the polar vortex diving south and phasing with the southern branch. The flow is also extremely amplified, and there is blocking in place to keep a lobe of the polar vortex in place over eastern Canada, which is our cold air source. While it is late April, this is not a normal spring pattern due to how far south the polar vortex is diving down. Typically in early spring, the polar vortex is sitting over the North Pole, undisturbed. However, on the euro it is displaced and several pieces are breaking off. This is as good of a pattern as it gets for monster blizzards in eastern mass, other than the whole late April thing (unfortunately, this cannot be ignored. It is a legitimate issue and will be a limiting factor to an extent). However, on the euro while it isn’t Arctic, the air mass is colder than it was for our current storm, and the trough digs more, and strengthens more than our current storm. Due to the extremely unusual clash of an early March like air mass combined with mid spring ocean temps and a highly amplified and blocked pattern, there is big potential in this pattern. I would favor more CNE/NNE/elevated areas rather than eastern mass for now due to the calendar date, but even as far south as Metfan is in the threat area and should keep an eye on this. If it comes together, watch out, the storm would be more dynamic, colder, and bring in more QPF than this one so it has tons of upside.

Yeah it looks like the low got to around Plymouth, just NW of the Canal. The Euro/Navy/Canadian blend I use had the right idea, and I actually got the track of the low right in my forecast (I expected a low right over the outer cape). The model blend that I use did a great job, and is not why my forecast busted. I don’t blame the navy at all for my forecast busting, as models are tools to make forecasts, they aren’t meant to rip and read. My forecast busted because I interpreted the model data incorrectly, which is on me as the forecaster, not the Navy. I forecasted 8:1 ratios and missed a warm layer resulted in more rain and less snow, and once snow did come ratios werent even 4:1 never mind 8:1. The gfs, as usual was garbage with it constantly retrograding the low into Worcester (not even close, they got a solid snow storm there). This was a fun storm to track and I feel that I learned a lot from it, and I plan on using what I learned to make better forecasts in the future.

Yep, not only would less QPF be wasted as rain (I must have gotten 2+ inches of QPF as rain), but the snow ratios would have increased as well (in many areas like where I live the ratios are horrible, less than 2:1, which is why snow totals are so low). If this same storm happened a month ago my forecast might have verified, and if it happened 2 months ago this storm would have been a top 10 blizzard of all time. I forecasted 15-25 inches of snow in my area (assumed 8:1 ratios, 2-3 inches liquid snow and .5-1 inches liquid of rain). However there must have been a sneaky warm layer at 925 mb (I can only look at 850 and 700mb, not 925mb temps on tropical tidbits, this may be a small part of (of course the biggest reason is I’m not a met and don’t really know what I’m doing yet) the reason why I keep overestimating snow ratios and underestimating how much QPF is wasted as rain. In reality, I ended up with around 1.5 in of rain and maybe .6-.1 inches of liquid equivalent falling as snow, but the ratios were less than even 1:1 as I have a slushy coating, not 6-10 inches of snow.

There are reports that it’s sunny out over the cape, likely because there is a low there.

Has not accumulated yet but it is snowing now in my area.

the rain snow line hit a brick wall like 10-15 miles to my NW. I might not get a flake outta this, unfortunately it appears the navy was wrong. I thought I might get 20 but the temps are just a bit too warm in eastern mass. CNE still looking good though for an overperformer

Temps have decreased to 37 degrees, still raining.

Strong slow moving monster ocean low, 2+ inches of QPF, low coming up the coast and stalling right over the cape, earlier transition to snow than expected in many areas, and now models are ramping up snowfall output as the storm is on top of us. Everything I look at screams overperformer

Gfs gives me more snow than you despite your area being to the NW of me in a mid April storm with marginal temps and a low hugging the coast. That makes no sense whatsoever.

There are reports that it’s already snowing in the Worcester and the storm is just getting starting to really get going, models have 2+ in of QPF there on top of the rain that has already fallen today. This is overperforming already

If the low doesn’t get NW of the canal this storm is going to surprise a lot of people. It appears the models have underestimated the degree of dynamic cooling which should bring higher totals to places like Worcester, with areas like the BOS-PVD corridor having a wide range of possible outcomes (anything from nothing to over a foot is realistic in this are). Going to be an interesting nowcast situation.

Down to 39 degrees now, still rain. Temps are cooling quickly though

It is 48 degrees and raining in my backyard right now

I’m not using the clown maps. No clown map besides maybe the long range nam (which is garbage anyways) showed anywhere near what I forecast. I don’t use snow maps when making forecasts, what I do is I look at the 500 millibar pattern to try and figure out if the surface presentation makes sense (on the euro it seemed to make sense), then I check the temp profiles in the upper levels, and if there are no warm layers I go through the run and look at how much QPF falls under a temp profile that supports snow. Based on what I have seen from the upper level temps, the snow maps are drastically underestimating the amount of snow. What the models say is a cold rain is a heavy wet snow based on the temp profiles. My analysis of the 6z euro was that the evolution supported over a foot of snow (thermal profiles supported 1.5-2 inches of QPF as snow, but ratios less than 10:1 so not more like 12-15 inches instead of 15-20 inches) in my backyard even though the maps only had like 6.

I disagree, the euro just 2 runs ago showed this scenario (the newer run isn’t as good, but it’s still very close). Even the most recent run the more aggressive models (Euro and Navy) are the better ones so I remain optimistic. The navy in particular is a foot+ right to the cape with 20+ in my area (I’m not quite that aggressive since I’m using the euro as well)

40 no, but 15 from Boston to Providence with 2 feet+ in the mountains? I can see it, we just need the low a bit more SE. It’s aggressive, but it’s within the realm of possibility.

That’s not what we want to see, hopefully it’s just an off run. Especially in mid April we need those dynamics to get a big snowstorm.

I wouldn’t say no one dares to call for a major snow storm....

Gfs would be nothing even in Worcester and northern mass, which is not in line with the consensus, so it can safely be disregarded. The low is unlikely to retrograde NW of Worcester. This close in the short range models like the href and nam are useful, so going with a Euro/Navy/Canadian/Nam/HREF blend, you get a low stalling right over the canal, with the NW end of the envelope (Canadian) getting the low to around my area, with the more se guidance (Navy) bringing the low 10 miles SE of Nantucket. I expect the navy to move NW and the Canadian to move SE, with the Euro having the right idea. Looks like Nam was SE but corrected NW, which makes sense (in line with the consensus now).

The way its trending it may not be a lesser version (probably will though, but that’s more of 97 being a beast than anything).