George001

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).

Elevated areas are getting hammered, but if things come together a changeover to several hours of heavy snow right to the cape cannot be ruled out. Understandably, most TV Mets aren’t calling for big totals in eastern mass yet but they did warn that it’s possible and it wouldn’t take a huge shift for that to happen (low needs to be a bit farther south and east, low over Worcester is no good for us in eastern mass, though your area should still get a lot). In my opinion it’s worth keeping an eye on even for as far SE as James, if everything breaks right even he might get a few inches (lower probability of course, but not impossible).

Correct

My top analogs for this storm: 1. April 1st 1997 2. March 8th 2013 3. Early Dec 2019 4. Feb 2 2021 I have them weighted 50/35/10/5 for 1, 2, 3 and 4 respectively. I’ve been big on the April 1st 1997 analog since I looked at the models a couple of days ago (hence the aggressive forecast), but looking at how the low just sits and stalls with a west to east fetch of Atlantic moisture being rammed into a cold airmass, producing insane QPF totals (2-3+ inches of liquid in some areas), I also like March 8 2013 as an analog.

The low just sits like 10-20 miles se of Nantucket for 12+ hours

It’s snowing right to the cape at hour 42 lol

I hacked the nam