40/70 Benchmark

Strong forecast for last night...maybe a hair too heavy in western Mass, and too light in southeastern NH. Give this one an "A", as the white Xmas lock (greater than 2" amounts) did indeed straddle I 495, as expected. https://easternmassweather.blogspot.com/2025/12/strong-forecast-for-tuesday-snows.html Saturday looks like a miss for most of the area, followed up by some rain on Sunday before turning colder. Merry Christmas!

@MJO812Congrats....I was wrong on December snow in NYC, and you were right. Reason being I missed the late month blocking. Let's see if you guys get above my 19-29" seasonal call.

Some folks need to practice staying out of "defense mode" when someone else insinuates that they may be wrong, and/or have bias....I know it's tough to do, but when you own shit like that, not only is it better for your own mental health and prospects for personal enrichment moving forward, but it disarms the other side entirely, and avoids the OT bickering that derails these threads. I have bias, and am often wrong...it's called being human. It's also fine if you don't actually agree that you are wrong....just tactfully explain it and the other side remains venomous, then they look like the ass.

Yea, I declared a mea culpa on that last night....I was wrong on latter December blocking, though did get the emergence of Pacific troughing right...end result is I will be too warm for December. and maybe January. The stat warming last month was more impactful than I had theorized.

Strong PV doesn't necessarily mean "torch", either...

Dude, we need less of this in the thread. Just disagree and move on...

Oh, I always want to see it at 50mb...sometimes 10mb is too high up to really do much.

Even I had a pine branch come down right in front of me just as I was finishing shoveling last night....very heavy stuff.

Same....just under 3". Once I hit Medford, it was down to thing coating, and then at Everett...GONE. Tough early season start for the city....

2.75" should do it.

2.5".....looks like it's starting to taper a bit, as growth has eroded some...

2.25" Great growth

First Call For Weekend Snows Major Accumulations "Blocked" From Region Latter November Stratospheric Warming Impacts On The Forecast The time has come for an Eastern Mass Weather mea culpa of sorts as it pertains to the stratospheric warming this past November. The winter outlook published during the early portion of November referenced the early December 2000 analog in postulating that this warming would not result in a reversal of the 850 zonal winds across the arctic. It was also (incorrectly) asserted on December 16th that this event did in fact barely fall short of the reversal criteria. This was an honest mistake, as it has been brought to my attention by the very meticulous Larry of the Americanwx.com forum, that there was barely a marginal reversal on November 28th. This is in more in line with the December 4th, 1981 warming that was cited as a potential alternative scenario that would in fact yield a full reversal. Ultimately, while the warming episode in-and-of-itself was relatively well forecast using the 1981 and 2000 analogs, the ramifications of it were certainly understated in that high latitude blocking was not expected to materialize prior to the new year, following the mid-month relaxation. However, it is now clear that this will be incorrect given that NAO blocking has rapidly burgeoned into existence on modeling in the period centered around the holiday week. This is approximately 30 days after the 11/28 reversal and consistent with the time lag of the development of high latitude blocking following a reversal per research, and this will have major ramifications on the potential weekend storm. Synoptic Evolution Yields North Atlantic "Traffic Jam" The emergence of the north Atlantic block this Christmas, on the eastern side of the NAO domain in response to the previously referenced stratospheric warming late last month, is what sets in atmospheric "traffic jam" of sorts. Normally, high latitude blocking helps to facilitate snow storms for the area, but in this instance the opposite is actually the case. Northern stream energy dumping into the Maritimes pools underneath the developing block once off of the coast and amplifies. At the same time, the energy for the weekend potential ejects out of the Pacific trough careens east-north-east over the top of the central US ridge and on a collision course with the Great Lakes by Boxing Day. The lead wave has developed into a deep, closed 500mb low near the 50/50 position by this time and is largely impeded from exiting to the NE by the nascent block to the southeast of Greenland. This results in yet another zone of confluent flow over New England since this system can not "get out of the way", so to speak, which shears and redirects the weekend system to the southeast as it approaches the region after descending from the peak of the ridge. This should relegate any significant snowfall to the southwestern quadrant of southern New England, primarily impacting portions of the state of Connecticut. FIRST CALL: Final Call will be Thursday night or Friday.

https://easternmassweather.blogspot.com/2025/12/first-call-for-weekend-snows.html FIRST CALL: Final Call will be Thursday night or Friday.

This wasn't a traditional SSW, as started in the troposphere and worked up...

Cool. Yea, still learning...

Chuck, I have in my notes that it's about 30 days for December warmings, and 45 days for November...maybe it will be closer to 30 days since it was so late in the month of December?

1"

So it doesn't have to be a reversal...

Yes, the speed of flow is a common theme...I thought you meant the overall patterns.

Implication being that they are all the same due to CC, but thing is they really aren't....I can tell you right now now this month won't be January 2024 or January 2020. Probably closer to 2022.

Should be me....I struggle to wrap my mind around that.

Same result, though...still got the lagged NAO.

Irony is I specifically made a note of your lag periods last off season, and then got the opportunity to practice it, and didn't. lol Do you still use it even if there is no reversal?

Yea, typo.