DAYS 1-5 (NOVEMBER 30 – DECEMBER 4)
Last day of November! Here comes another weather system in a month that’s seen quite a few pass by, but a lack of larger storm events. This is no different. A low pressure system moves quickly through the Great Lakes and into southeastern Canada. Its warm front is going by our region this morning with a blanket of mid level clouds, but some snowfall being generated by the front is passing north and west of our area (WHW) as was expected to happen. It’s the cold front trailing the low that will bring us a round or two of rain showers from later this afternoon into this evening as it sweeps across the region from west to east. And then we welcome December with a chilly, blustery day on Monday, but with dry conditions. This sets the stage for our next “weather system” – a much talked about system coming our way from the southwest on Tuesday. As usual, guidance has been all over the place in its array of simulations repeatedly run on the family of models we have access to, for better or for worse, adding a lot of noise to the information stream, but what really counts is what this system is going to actually do to our region. This is my best educated guess: This storm threat is born of 2 “pieces of energy”. The first one is a trough swinging through the Ohio Valley toward the Northeast. The second is a wave of low pressure from the Gulf, moving across the Southeast, with a low pressure area taking shape off the North Carolina Coast. These 2 systems would have to fully merge before a stronger storm could result, and that won’t be happening until they are east of our longitude. What we get is a system that is the result of the process of the merger. Most of our moisture is actually going to come from the northern system, with minor infusion from the southern one. The track of the low associated with the southern system is going to be pretty far off our coast as it goes by, and while it will be strengthening, it’s not doing so at such a rate that helps draw in colder air. We also will lack a cold high to the north, which in the progressive nature of the pattern will be sliding away through Atlantic Canada as what remains of the northern system progresses east northeastward. Despite the track pretty far south, we will be in the circulation of the newer storm, which as you know at this time of year is going to pull ocean-warmed air into the coastal plain. Also, this will be a fairly short-duration event – from about mid morning to mid evening Tuesday – approximately 12 hours. Putting all this together, we’re looking at greatest chances for accumulating snow that you have to perform snow removal for outside of the I-95 belt – favoring higher elevations of southern NH and central MA, while chances for that kind of snowfall drop off rapidly the further east and south you go, in favor of a rain event – which could start as mix/snow and end as mix/snow for some depending on the precipitation and temperature profile as the system comes through. There will be colder air coming in right behind the system, so icing up of untreated surfaces will be a concern by the early hours of Wednesday. Wednesday’s weather will be dry, chilly, and breezy behind the system. A cold front is expected to cross the region on Thursday from northwest to southeast, bringing the chance of rain and snow showers. I’ll look a little more closely at that for timing and rain showers vs. snow showers in the next update.
TODAY: Mostly cloudy. Rain showers likely west to east by late-day. Highs 45-52. Wind S 5-15 MPH.
TONIGHT: Mostly cloudy with rain showers likely in the evening. Partly cloudy overnight. Lows 30-37. Wind shifting to W 10-20 MPH, higher gusts.
MONDAY: Sun/cloud mix. Highs 38-45. Wind W 10-20 MPH, higher gusts.
MONDAY NIGHT: Clouding up. Lows 22-29. Wind N up to 10 MPH.
TUESDAY: Overcast. Precipitation arrives prior to midday north and west of Boston, around midday Boston southward – snow to potential mix I-495 to I-90 north and west, snow/mix to rain I-95 belt, mainly rain but can start as brief mix Boston south. Highs 33-40 except 40-47 Cape Cod / Islands. Wind NE 5-15 MPH.
TUESDAY NIGHT: Precipitation ending followed by overnight clearing. Expected snow totals generally a trace to 1 inch I-95 belt with closest to 1 inch most likely inland, 1 to 3 inches interior southern NH and I-495 / I-90 region west from I-495 westward, 3 to 6 inches higher elevations Worcester County to interior southern NH, with a slight chance of isolated 6+ amounts at highest elevations. Lows 22-30. Wind shifting to NW 5-15 MPH.
WEDNESDAY: Sunny to partly cloudy. Highs 32-39. Wind NW 15-25 MPH.
WEDNESDAY NIGHT: Mostly clear. Lows 22-29. Wind SW 5-15 MPH.
THURSDAY: Variably cloudy. Chance of rain and snow showers. Highs 37-44. Wind SW 10-20 MPH shifting to NW.
DAYS 6-10 (DECEMBER 5-9)
With a somewhat active jet stream pattern (doesn’t mean all hits here) it is somewhat difficult to time unsettled weather threats, but eyeing late December 5 to early December 6, and December 7 as potential unsettled time frames. No solid indications of major storminess and too early to determine any precipitation types / transitions. Overall temperature pattern favors near to slightly below normal.
DAYS 11-15 (DECEMBER 10-14)
Colder pattern may transition to a little milder heading toward mid month as upper air pattern shifts somewhat. A couple of precipitation threat windows exist in this time frame with fine-tuning to come.
Thanks TK !
That’s yet another excellent discussion, which clearly explains your thinking !
Wordle: 4
I’m a Steelers fan today. 🙂
Wordle Fail
Wait….arent the Steelers playing the Bills?
Yes !!
This is a comparison between a 06z and a 12z run, but it’s interesting to note that there is about a 400 mile difference in the position of the surface low at closest pass to our area between the 06z RRFS (which has the low basically where my discussion indicates) and the 12z NAM (12km version) which has the low passing right overhead.
Thanks TK
Looking like an advisory level snowfall for the interior on Tuesday at the moment.
Thanks Tk
I hope Dr S will post the channel 7 snow map from this morning !
Their map seems to be most influenced by the Euro.
If the Euro has this simulated correctly, then good for ch 7.
0Z EURO 10:1 24 hour snow
https://www.pivotalweather.com/model.php?m=ecmwf_full&p=sn10_acc-imp&rh=2025113000&fh=78&r=us_ne&dpdt=&mc=
6Z EURO says, WHAT????
https://www.tropicaltidbits.com/analysis/models/ecmwf/2025113006/ecmwf_mslp_pcpn_frzn_neus_21.png
Those 0Z amounts would have to be shifted N&W
The 00z euro had a weird setup at 850mb with almost 2 (850mb) lows, one near the south coast like other models and then this 2nd, compact one south of it, which maybe explains its deep low south of the benchmark. I think this polluted the 00z run and made it useless.
https://www.pivotalweather.com/model.php?m=ecmwf_full&p=850wh&rh=2025113000&fh=72&r=us_ne&dpdt=&mc=
That 2nd one east of the Maryland coastline. I’m ok with the one that’s broad and weaker to its north, but I think that second one is very questionable.
Here is the CH7 snow map. To me, it looks like they did incorporate the 6Z Euro
https://ibb.co/xqZhVtV2
Good morning and thank you TK.
40 here after low of 30
Ocean: 49
Wordle: 6 after Zilch with guesses 1 & 2. PHEW!!!
re: Tuesday
Not expecting much here, that is for sure.
I will note, however, that even the NAM has trended a little farther S&E
6Z snow
https://www.pivotalweather.com/model.php?rh=2025113006&fh=72&dpdt=&mc=&r=us_ne&p=snku_024h-imp&m=nam
12Z
https://www.pivotalweather.com/model.php?rh=2025113012&fh=66&dpdt=&mc=&r=us_ne&p=snku_024h-imp&m=nam
I was MOST encouraged by the 0Z EURO ONLY to be DASHED this morning when I viewed the 6Z EURO.
Oh well, it is what it is. Who said that? It’s a silly statement, but I like it and very apropos today.
Thank you TK. A good positive write up this am.
https://www.wpc.ncep.noaa.gov/Prob_Precip/idss-map/mapgen.php?office=BOX&summary=true&pointpreferences=BOX&ptype=prob_sn&product=expected_range&2025113014
Some new ranges this year ??
1-6, 1-7, 0.5-5
I forgot 1-8 and 1-9
That has to be a mistake. Pretty HILARIOUS just the same!!
🙂 🙂 🙂
I’m in the pinpoint 1-9 zone! 🙂
I got Wordle in 1-fail today.
With a new precision update, I got Wordle in 4.
Nice job
WTF is that map!? LOL!
Even the RDPS wants to rain on our parade
https://www.pivotalweather.com/model.php?m=rdps&p=prateptype-imp&rh=2025113012&fh=60&r=us_ne&dpdt=&mc=
NWS HIGH END (1 in 10 chance) snow map
https://www.wpc.ncep.noaa.gov/Prob_Precip/idss-map/mapgen.php?office=BOX&summary=true&pointpreferences=BOX&ptype=prob_sn&product=high_end&2025113014
And for completeness, their low end snow
https://www.wpc.ncep.noaa.gov/Prob_Precip/idss-map/mapgen.php?office=BOX&summary=true&pointpreferences=BOX&ptype=prob_sn&product=low_end&2025113014
It’s lock. Place your bets online!
Where is my cold eastern Canadian high? I’m looking for it.
About 500 miles too far east – that’s where. 😉
https://www.pivotalweather.com/model.php?m=rdps&p=850wh&rh=2025113012&fh=60&r=us_ne&dpdt=&mc=
Here’s the RDPS 850 mb map.
A broad, not strong 850 mb centered around the eastern tip of Long Island that at hr 63 tracks over the islands. That’s far north as we know the best snow is a decent distance north and west of the 850 mb low track. I still even think the inland snow amounts are overcooked on the coldest models.
https://www.pivotalweather.com/model.php?m=icon&p=850wh&rh=2025113012&fh=60&r=us_ne&dpdt=&mc=
Here’s the 12z ICON location of the 850 mb low !!
I think the 00z euro was polluted by a strange 2nd 850 mb low which explains its strong low south of the benchmark. I hear the 06z euro may have corrected and I expect the 12z euro to correct.
850 mb low too far north and no polar high for this system.
The ECMWF model initially had the idea of a slightly weaker system slightly further SE correct, but in the last several runs it’s kind of lost the overall idea of this thing – I abandoned it late yesterday.
Probably not far off on amounts.
https://www.wpc.ncep.noaa.gov/Prob_Precip/idss-map/mapgen.php?office=BOX&ptype=prob_sn&summary=true&state=MA&pointpreferences=MA&product=expected&2025020905
IMO that’s fairly reasonable.
Agree. That map looks reasonable.
Thanks TK.
1,374 ❄️
Snowfall forecasts from around the dial: https://ibb.co/zH4prLxJ
Wordle in 2.
Thank you!
There is a corrected NWS map I posted above.
Wow!!
Awesome wordle and thank you for the maps
Awesome !
ICON Kuchera snow
https://www.pivotalweather.com/model.php?m=icon&p=snku_024h-imp&rh=2025113012&fh=72&r=us_ne&dpdt=&mc=
The tv mets seem focused on interior SE MA as the “wild card” for heavy snow.
TK – Obviously you haven’t mentioned this in your discussion even as a remote possibility but what are your thoughts on that?
GFSRAINORAMA!
https://www.pivotalweather.com/model.php?m=gfs&p=prateptype_cat-imp&rh=2025113012&fh=60&r=us_ne&dpdt=&mc=
This low placement would have been oh so much better
with a nice COLD Hight To Our North!!!
GFS 24 hour Kuchera Snow
https://www.pivotalweather.com/model.php?m=gfs&p=prateptype_cat-imp&rh=2025113012&fh=60&r=us_ne&dpdt=&mc=
You did it again 🙂
Here is the snowmap:
https://www.pivotalweather.com/model.php?m=gfs&p=snku_acc-imp&rh=2025113012&fh=69&r=us_ne&dpdt=&mc=
That is a colder/further SE solution than what it had been showing. It is coming back to Earth. Even gets heavy snow into my area at the start of the system and again at the end. Accumulations from nothing in southern Tolland County to 8″ in the northern part of the county near the MA border. Threading the needle in many areas as I said last night!
The cutoff between a lot and nothing in the western and NW suburbs of Boston is also pretty impressive.
I guess I haven’t been with it lately. 🙂 🙂 🙂
https://www.pivotalweather.com/model.php?m=gfs&p=850wh&rh=2025113012&fh=60&r=us_ne&dpdt=&mc=
12z (850 mb low) location
A little further south than the icon/RDPS
http://forecast.weather.gov/data/obhistory/KBOS.html
Different setups, but look at what the wind off the ocean has done in a handful of hours to Logan’s temp and dewpoint this morning.
yup!!
Thanks TK.
Light snow in Amsterdam NY this AM and about 33F. Just a dusting on top of the already snowcovered ground but not really accumulating on the pavement.
Heading back to CT later this PM and getting the snowblower and shovels out of the shed. I expect I expect I may be scraping some slush off the driveway Tuesday night. Regardless, If I dont need them Tuesday, likely I’ll be needing them relatively soon.
Nice looking snowmap from the NWS for CNE and NNE. Continued good news for the ski areas:
https://www.americanwx.com/bb/uploads/monthly_2025_11/mapgen.thumb.png.3fcf3bdd53306056fa44fc6bbe07ad1e.png
Interesting writeup from the NWS:
Significant detail differences continue to impact the forecast for a low pressure passing by our region Tuesday into Tuesday night. Some of the latest guidance suite notably the GFS and Canadian, have trended their tracks farther north. This time being inside of the 40N/70W benchmark. Meanwhile, other members continued to linger near or south of that point. With no blocking high over Quebec to trap low level cold air across southern New England, the track and timing details will greatly impact temperatures. Minor changes to temperatures around freezing will have a major impact on precipitation type, and ultimately snowfall accumulations.
The latest NationalBlend data continued to show some mixed messages, highlighting the remaining uncertainty. While uncertainty decreased across portions of central and western MA and northern CT, uncertainty increased across eastern MA. The 50 percent confidence interval for 24-hour snowfall ending 7 AM Wednesday lowered to 4-5 inches, while across eastern MA it increased to 10-14 inches. Expecting changes almost up to the last minute with this particular event.
Continue to have the greatest confidence in accumulating snowfall across the higher terrain of the northern Worcester Hills and east slopes of the Berkshires. Still no certainty on the amounts. However, there are moderate probabilites (50-70%) for at least 3 inches of snowfall, and about a 30-45% chance for 6 or more inches of snowfall. The probabilities only go down from there towards the I-95 corridor between Boston and Providence, about 30-45% for at least 3 inches of snowfall and 15-25% for at least 6 inches of snowfall.
6z Euro AI Snowmap at 10:1
https://www.americanwx.com/bb/uploads/monthly_2025_11/floop-ecmwf_aifs-2025113006.sn10_024h-imp.us_ne.gif.c67cfd555d4b28b3e7f9fd930b885c1f.gif
UKMET 10:1 snow
https://www.pivotalweather.com/model.php?m=ukmo_global&p=sn10_acc-imp&rh=2025113012&fh=66&r=us_ne&dpdt=&mc=
https://www.pivotalweather.com/model.php?m=gefsens&p=snodpc_024h-mean-imp&rh=2025113012&fh=66&r=us_ne&dpdt=&mc=
Just watched a very nice movie entitled
An Angel for May.
I saw this movie more than 20 years ago and recently I have been looking for it and could not find it. As much as I don’t like AI, it located it for me.
Free on You Tube
https://www.youtube.com/watch?v=KRa_Us4Pv-Q
Trailer
https://youtu.be/igzPbkI6qA4
Awesome. Will watch this week. Thank you
Euro will be out soon. This should be interesting.
https://www.pivotalweather.com/model.php?m=ecmwf_aifs&p=sn10_024h-imp&rh=2025113012&fh=66&r=us_ne&dpdt=&mc=
Euro-AI
I’m posting these, but don’t necessarily agree with them, lol.
That is a given. But we can hope for verification on those we like OR not. 🙂
If we get a cold scenario to verify, I could agree that the very top of blue hill might get a few inches of wet snow. (635 ft per blue hill website)
I don’t know, I feel like we’ve live this scenario before and I seem to remember the models upping snowfall projections about 2-3 days before the event and then as we get to 24 hrs before, they adjust downward.
Still know there’s no high to the north and they 850 mb low may be just a little bit too far north.
That’s why I’m kind of skeptical.
Surface
https://www.pivotalweather.com/model.php?m=ecmwf_aifs&p=sfcwind_mslp&rh=2025113012&fh=60&r=us_ne&dpdt=&mc=
Even the EURO AI would have a period of rain or sleet for Boston.
850mb
https://www.pivotalweather.com/model.php?m=ecmwf_aifs&p=850th&rh=2025113012&fh=60&r=us_ne&dpdt=&mc=
Thank you TK!
Wordle: 5
Nice.
12Z Euro shows a heavy “mix” along the coast. Now is this rain ^ snow mixed? rain and sleet mixed? Or is it sleet?
https://www.pivotalweather.com/model.php?m=ecmwf_full&p=prateptype_cat_ecmwf-imp&rh=2025113012&fh=60&r=us_ne&dpdt=&mc=
850 and 925 mb temps suggests a boundary layer issue and
it is a rain/snow mix
https://www.pivotalweather.com/model.php?m=ecmwf_full&p=850th&rh=2025113012&fh=60&r=us_ne&dpdt=&mc=
https://www.pivotalweather.com/model.php?m=ecmwf_full&p=850th&rh=2025113012&fh=60&r=us_ne&dpdt=&mc=
Good question !!
On the euro-AI, that 850 mb map you posted just above ….
Ok, it’s got an 850 mb temp slightly above freezing, a sfc temp of 36F and it’s projecting several inches of snow !!
No !! And I feel like that’s a common theme on some models on the SE edge of their snow totals, where the project 6-8 inches of wet snow, but then you look at the 850 mb temps and the sfc temp and it’s like, how are you going to accumulate that much snow in that temp profile?
BUT the regular EURO has 850 and 925 mb temps below freezing.
12Z EURO 10:1 snow
https://www.pivotalweather.com/model.php?m=ecmwf_full&p=sn10_024h-imp&rh=2025113012&fh=66&r=us_ne&dpdt=&mc=
Totals on ground would be less due to warm ground and the mix or very low ratio snow.
BUT this is the COLDER solution if you like snow.
Here too.
I thinks it’s hr 60 at its most intense, where that 10.2 inch snow projection temp is ….
The 850 mb temp is either -1 or -2C and the sfc temp projects 34F.
I’ll take the vast under on that 10.2 with that profile.
https://www.pivotalweather.com/model.php?m=ecmwf_full&p=850th&rh=2025113012&fh=60&r=us_ne&dpdt=&mc=
https://www.pivotalweather.com/model.php?m=ecmwf_full&p=sfct-imp&rh=2025113012&fh=60&r=us_ne&dpdt=&mc=
Remember those snow projections are for 10:1
I’ll bet the ratio would be something like 6 or 7:1 cutting totals by 40-30 %
I suppose the ratio could even be 5:1,
This system is getting interestinger and interestinger.
No matter what happens, it’s been a blast following the model runs. 🙂 🙂 I wouldn’t want to have the responsibility of making
a proper forecast with this one. Bust potential either way is huge.
I suppose the safe bet would be for RAIN along the coast, but it doesn’t always work that way. Looking forward to this event for sure!!
Not for me.
See above.
The models snow projections are so misleading once you examine the projected column in that same spot.
I feel bad for all the hope that may be reading which is likely to be met with vast disappointment.
Reading = creating
Disagree. See above. Sure those totals won’t be realized, but cut them in half and I’d take it for a 1st system of the year. 🙂 🙂
Of course we have many models in total disagreement, so we
are arguing about only one possibility. 🙂 🙂 🙂
Indeed 🙂
Absolutely true
https://www.pivotalweather.com/model.php?m=ecmwf_full&p=925th&rh=2025113012&fh=60&r=us_ne&dpdt=&mc=
Look at that 10.2 in RI, quite some distance south of RI
Here’s the 925 mb temp profile, at that location it’s arguably btwn 0 and +1C !!!!!!!!!!!!!
Garbage snow projections, I don’t know what these models are doing, but something is vastly amiss.
Again 10:1. IN reality with that profile, ration would be something like 5 ot 6:1, perhaps even less.
So call it 4-6 inches and not 10.2 That would be more real and it might even be less than that.
EXPERIMENTAL FIM MODEL 0Z last even total snow depth
https://fim.noaa.gov/FV3new/displayMapUpdated.cgi?keys=ccpp_fv3gsd_l127_alt:&runtime=2025113000&plot_type=snod_NE_sfc&fcst=084&time_inc=360&num_times=29&model=fv3&ptitle=Experimental%20UFS%20Model%20Fields&maxFcstLen=168&fcstStrLen=-1&domain=NE&adtfn=1
Not sure when/if the 12Z version will be available.
I see that the RRFS A model now runs out to 84 hours.
Did TK say that this model will replace the NAM very soon???
I think I saw that?
The aim is to replace it ASAP – but they are soliciting comments from the weather community to help with this decision.
I say it’s time. The NAM is outdated and nearly useless with a few exceptions. The 3km still does ok with some things, but from what I have seen, it’s future replacement is equal to or better than it on most set-ups.
I am still not over losing the ETA/AVN/NGM suite…
About to put up the Christmas tree and then football 🙂
I will be the happiest person if the colder models snow projections verify because it will make a lot of people in general and here on the blog, very happy.
When I post things that work against snow, (or that I think work against snow), I promise it’s not done to antagonize. I hope that proof of that is I usually include some link about something in the event I think might work against snow or the amount of snow being seen in model projections. I’m looking forward to a future setup I think will dump a good snow in both Boston and Marshfield 🙂
Ok, now for this tree 🙂
You don’t need to explain anything here Tom regarding your forecasts . From day 1 I have always enjoyed reading your posts as you know your weather & we are neighbors.
Absolutely understood
Looked at the 12z stuff and after doing so, there are no changes or updates to my discussion from this morning. It’s adequate.
I feel like this storm is creating a lot of both sides antagonism and its driven by online sources and its uptake driven by bias, hope, and naïveté. Sound familiar?
This storm is not that hard of a forecast. Closer to the coast, little impact. Inland, light impact. Higher elevations, moderate impact.
0-1″ coast
1-3″ inland
4-6″ elevation (maybe more 1,000-1,200′)
May but to me It isn’t antagonism. It’s the amount of negativity. Everywhere
12z Euro EPS Ensemble Mean Snowmap (keeping in mind this is 10:1):
https://www.americanwx.com/bb/uploads/monthly_2025_11/1079957472_index(28).png.9fa7eed9a689ddb9d385baf7ef967901.png
Still not caving on the colder/further SE solution.
Broken link, try this:
https://imgur.com/3Obf1XP
And this is the almighty European Ensemble.
Interesting. I am dying to see how this all plays out.
The snow lover in me wants to believe this ensemble, but
the realistic side of me says there is no high to the north and the ocean is 49 degrees, thus rain/mix near the coast.
I know it could go either way, but I should be leaning rain/mix, but I want so much for it to be SNOW!!!!
Rain / mix Boston
https://www.americanwx.com/bb/uploads/monthly_2025_11/1079957472_index(28).png.9fa7eed9a689ddb9d385baf7ef967901.png
Copy and paste also works.
Winter Storm Watches posted for all of southern VT, NH, and Maine, northern Litchfield County CT, and all of Massachusetts outside coastal NE MA, Boston metro and SE MA…
https://www.weather.gov/box/
Watch in MA is for greater than 6″ of snow.
NWS Expected snowfall
https://www.wpc.ncep.noaa.gov/Prob_Precip/idss-map/mapgen.php?office=BOX&summary=true&pointpreferences=BOX&ptype=prob_sn&product=expected&2025113019
Thank you, TK.
I’m simply not buying anything (in a figurative sense) that many mets on social media have been posting for the weather this December. Frankly, I’m not even sure the cold will last that long this upcoming month, let alone there being lots of snow chances. I’d like to see both cold and snow, but I’ve learned to not be baited into forecasts based on hope and wishful thinking.
I haven’t seen an SAK weekend update recently. Did I miss one?
JMA, thank you for your post. Your predictions seem about right. I think of this early December storm as having some features of a mid to late March event.
I haven’t seen a SAK post in a while. Hope he’s ok.
You’re not paying attention I post . Maybe not as much as I’ve been working a ton of overtime at the Hospital ( always so much available)
He means SAK, not SSK 🙂
He’s paying attention. 😉
Yes, he is and so are we.
That is a switch for me.
I guess I’m not lol , these glasses suck
I’ve been on the phone for over two hours trying to straighten out an order from bed bath and beyond and it may be days before it’s fixed.
I’m surprised I noticed
Yuck, good luck !
NWS write-up of two camps.
Scenario one, which will serve as the basis for the forecast would
keep the low-pressure system inside of 70N/40W, and is supported by
the GFS, NAM, and GEM. Onset of the precipitation Tuesday morning is
likely a singular PType, snow, due to the thermal profile from the
surface to 850mb remaining below freezing. This is short-lived as a
southerly LLJ leads to WAA, increasing temperatures above freezing
for areas outside of the higher terrain. There is plenty of moisture
to be had, origins are out of the Gulf. Probabilities of more than
0.5″ of precipitation are 60-90 percent for the CWA. As for 1.0″ or
greater, those are 20-40 percent, plenty to work with. Thinking this
event will be progressive as there is no blocking downstream over
the North Atlantic. As for the dynamic set up, the 750mb wave does
not close off until reaching eastern Gulf of Maine and the 850mb low
is nearly over southern New England, not a great set up for snowfall
in the lower elevations. While the coastal plain deals with a cold
rain, snowfall will be based in the higher elevations of central and
western Massachusetts. Given the uncertainties, there is a low to
moderate level of confidence the greatest snowfall, more than 6.0″
occurs in the northern hills of Worcester County and eastern slopes
of the Berkshires. Here GEFS have probabilities 40-60 percent, while
the CMC ENS are 80+ percent. Given the guidance mentioned above have
been in the same camp the past few days, opt`d to issue a Winter
Storm Watch in collaboration with neighboring WFOs and WPC for much
of Massachusetts west of I-95.
Scenario two is the outlier solution, though still worth paying
close attention, as the ECMWF and UKMET advertise the low-pressure
system passing further south. While the UKMET is joining this camp
the ECMWF has not deviated and what this solution does is shunts the
greatest axis of snow towards eastern Massachusetts and northern
areas of Rhode Island. The dynamic set up differs a bit from the
previous scenario with the 700mb wave closing off near Cape Cod and
the 850mb low just south of the islands. ECMWF ENS show probabilites
of 6.0″ or more of snowfall between 50-70 percent across most of
eastern Massachusetts and northern Rhode Island. Lower probabilites
of 20-40 percent for western Massachusetts. Something to monitor,
especially as we enter the window for high-res guidance.
Give me scenario #2 please.
Then there is scenario #3 which basically splits the difference.
THE RRFS-A model
https://www.pivotalweather.com/model.php?m=rrfs_a&p=snku_acc-imp&rh=2025113018&fh=66&r=us_ne&dpdt=&mc=
This one seem the most realistic to me for whatever that is worth.
Some front end snow, mix or switching back and forth in the middle and snow at the end.
This morning the tv mets seemed focused on interior SE MA as the “wild card” for heavy snow. If I understood correctly, the coastal front may set up just SE of those locations and the snow would develop just NW from there.
TK – What are your thoughts and will the evening mets continue that line of thinking or is that scenario now off the table?
Philip, I’ll take a weather enthusiasts guess at your question ….
2 reasons I don’t think the coastal front is a big player in this scenario
https://www.pivotalweather.com/model.php?m=gfs&p=850wh&rh=2025113018&fh=54&r=us_ne&dpdt=&mc=
1) I think coastal fronts create enhanced snow to the west and northwest of them when you have a strong NE (850 mb level) jet advecting additional moisture off the ocean up and over that coastal front boundary. This set up isn’t producing most of the precip that way. It doesn’t have much of a NE (850 mb jet) at all.
2) to further enhance snow northwest of the boundary, it works best if the temp is say 36F at Logan and Marshfield, which it might be in this case, but a lot colder (like 20F or less) west of the boundary and I don’t think that’s the case here.
So, I don’t think the coastal front is a big player here, even though there might be one there, I don’t think it’s the good strong ones we are used to.
This also applies to the much colder euro
It has a very, very weak 850 mb jet to the north of the 850 mb low.
https://www.pivotalweather.com/model.php?m=ecmwf_full&p=prateptype_cat_ecmwf-imp&rh=2025113012&fh=60&r=us_ne&dpdt=&mc=
https://www.pivotalweather.com/model.php?m=ecmwf_full&p=850wh&rh=2025113012&fh=60&r=us_ne&dpdt=&mc=
Sorry, meant this one, not the sfc map
It’s funny, we track the last 6”+ snow and it was that massive blizzard 4 winters ago.
Marshfield had blizzard conditions for 8 hrs ago. We snowed at 2” per hour for those 8 hrs in a row.
The moist, 850 mb low level jet, perhaps we could call it a mini atmospheric river, that, that system had was nuts !! It’s etched in my brain what it looked like on the 840 mb map and to be sure, those bands were enhanced along the coast cause the coastal front was sitting 15-20 miles out east over the ocean and it just was nuts that day.
1,374 days ago. ❄️ 😉
My line of thinking never changed yesterday – and still hasn’t this morning.
https://buffalowebcam.com/live-webcams/buffalo-ny-elmwood-ave-mr-pizza
That current system bringing us rain has turned the wind SW in Buffalo and the lake effect is developing.
C-3” of snow in Marshfield on the ch 5 snow map I see on their website.
3-6” JUST west of the city.
I wouldn’t be surprised if the precip started as a bit of wet snow in the air early Tuesday and I wouldn’t be surprised if even Boston’s suburbs get a dusting or even a coating early Tuesday morning.
But, I just don’t agree with those amounts overall. I think they are way too high, especially low elevations in eastern Mass.
I 100% do not agree with this at all for Boston / south !!
Heavily influenced by the Euro and ukmet.
Anyone have access to the 18z Euro yet? Usually available on tropical tidbits by about 7-8 PM.
it shifted a tad north with the heaviest snow band moves the 6 inch north and west of the city and coast.
Just watched AJ. I can verify the above. I might add, JP is in the 3-6 inch range, likely closer to 3 than 6.
CH4 snow map
https://ibb.co/MDDT914w
Here’s the recently updated one:
https://ibb.co/zDSNsm0
Thanks SClarke.
https://www.pivotalweather.com/model.php?m=ecmwf_aifs&p=sn10_024h-imp&rh=2025113018&fh=60&r=us_ne&dpdt=&mc=
4.2 inches around Boston if I’m reading correctly ?
Ok ….
https://www.pivotalweather.com/model.php?m=ecmwf_aifs&p=850th&rh=2025113018&fh=54&r=us_ne&dpdt=&mc=
https://www.pivotalweather.com/model.php?m=ecmwf_aifs&p=925th&rh=2025113018&fh=54&r=us_ne&dpdt=&mc=
https://www.pivotalweather.com/model.php?m=ecmwf_aifs&p=sfct-imp&rh=2025113018&fh=54&r=us_ne&dpdt=&mc=
850 mb temp at crunch time over Boston is 0 to +1C, 925 mb temp is +1 to +2c and the sfc temp is 35F and the model suggests 4.2 inches of snow.
Euro doing this too.
I think that’s a major red flag.
BZ should have kept its first map.
I think these inside 495 ants showing up tonight have a high likelihood of failing.
Additionally, the further southeast track on the models that have a snowier outcome, you know where the heaviest precip is likely to be …. Mostly towards the coast, cape and islands with more moderate amts inland. And with less QPF inland, I think those amts are overdone too, it’ll snow, just not enough precip to verify 6-9” out there.
Lastly, the ch 5 weather cast is saying c-3 at Logan and 3-6 just west of the city and then the model they used to simulate was one of the warmer models with rain in Boston and its suburbs and it simulated a temp of 40F at Logan. I find ch 5 weather casts excellent, tonight did not meet that standard. And that’s too bad because the meteorologist on tonight is really good, in my opinion, overall.
Again, bring back the first BZ map, it’s the best TV weathercast map
And I agree with TK and JMA on their amts too.
Apologies if I misssed it. Is this late Tuesday into Wednesday or most of Tuesday afternoon.
Thsnk you
Tuesday, all day.
Ending Tuesday evening.
Oh. Thank you very much not sure why I thought ties night into wed. I’ll be rescheduling a couple of appointments tomrroe
https://www.pivotalweather.com/model.php?m=hrrr&p=sfct-imp&rh=2025120100&fh=44&r=us_ne&dpdt=&mc=
00z HRRR mid-late afternoon temp projection
Tuesday
Sfc map
https://www.pivotalweather.com/model.php?m=hrrr&p=ref1km_ptype&rh=2025120100&fh=46&r=us_ne&dpdt=&mc=
Well, they have the 11pm newscasts to make some changes.
Is that the most likely scenario?
No, but I take note because it’s entered into the HRRR’s range.
I think it’s a believable one though because with the high in retreat to our east by Tuesday morning, this high resolution model may do a better job than a global model of how fast the marine layer may warm with a SE, then E wind a good part of Tuesday.
Up to .19 inches in marshfield today and am getting clipped by more decent rain from this next batch passing thru SE Mass
https://radar.weather.gov/station/KBOX/standard
0.26 here
https://www.pivotalweather.com/model.php?m=hrrr&p=ref1km_ptype&rh=2025120100&fh=48&r=us_ne&dpdt=&mc=
Back to that 00z HRRR run, 2 things ….
1) I think it may be what TK described in his discussion above. It’s a northern and southern piece, at first, it’s the northern piece that starts the precip and then the southern piece is adding some in, but they are not looking like they are phasing.
2) that low in this simulation is going to have a nice winter track, but that doesn’t matter in early December without a cold high to the north and for whatever reason, the euro and now euro-AI seem to be not handling it very well.
According to the Ch.7 met, Boston gets their snow on the backside as the storm moves away.
Cool
Tuesday evening
Without serious lift and cold behind it, backside snow does little or nothing. I’ve seen some nice backside snow in Boston. – March 2005, for instance – but these are rare events. The one I am referring to was remarkable: Intense snow, wind, and biting Arctic cold in March as a strong system departed. We ain’t getting that on Tuesday.
Well, if this were election night, the early returns don’t look good. 0 for 3 (HRRR and both Nams)
Hopefully the outstanding models in the 00z suite will turn things around. 🙂
Make it 0 for 4 as RDPS says rain as well. Not looking good and 18z euro said forget snow at the coast as I suspect tonight’s euro and unkmet do as well. IF no, then I wouldn’t know what to say. I’M betting the correct this evening. Ther’s always next time.
Is this at coast?
NWS updated as of 10:09 pm
https://www.weather.gov/images/box/winter/StormTotalSnow.jpg
Cutting back on totals?
Some of these snow maps looks ridiculous. All TOO HIGH, imho.
More runs tomorrow. I’ll bet anything the EURO backs off tonight. I’d be SHOCKED if it holds course.
https://ibb.co/wm4mZrk
Evening snowfall map lineup
Thank you.
lol Nam
New post…