40/70 Benchmark

Major-Long Duration Winter Storm Likely for the Deep Interior Friday-Saturday Elevations favored The first major winter storm of the season look to arrive early on Friday, and as advertised in last week's initial threat assessment, it looks to be a mixed bag that promises to present many precipitation type issues across the region The Synoptic Situation: Deep low pressure will be begin to encounter the negative NAO block currently in place, as it moves northeast through the plains on Wednesday. Ordinarily, a storm system on the trajectory in the plains would mean a mild rainstorm for most of New England, however, it will ultimately succumb to resistance from the block and redevelop to the east. This is what will allow a portion of the area to still experience a significant snowfall. But notice that while the block ultimately does win the battle, it is not before the powerful primary closed low in the in midwest has forced the block to cede just enough ground the system to make it all the way north into the Great Lakes. This is why it is important to remember that it is the synoptic scale nuances that dictate the details of a storm, not necessarily the mode of large scale index, as evidenced by the fact that the NAO remains quite negative despite the small cessation of ground that proves crucial to the forecast. Anticipated Storm Evolution: Precipitation should begin as snow anywhere roughly outside of I495 and off of the south coast after midnight early Friday morning. However, the aforementioned stronger and more resilient primary low results in a stronger southwest flow aloft for a longer duration of time that ultimately scours out the antecedent cold more efficiently, and allows the secondary to track closer to the coast, which creates an easterly fetch into the lower levels of the atmosphere. Given the fact that sea surface temperatures this early in the season are near 50 degrees, this renders it impossible for any initial snowfall to last very long on the coastal plain of southern New England. Thus the precipitation will rapidly transition to sleet and then rain anywhere east of the Worcester hills early Friday morning, so that by midday Friday, only the hills of Worcester county, northwestern Connecticut and the Berkshires are snowing heavily. While it may continue to snow at some valley locations of western mass during Friday afternoon, it will likely struggle to accumulate as efficiently as locales at higher elevations above approximately 700', where power outages will be possible across the Berkshires, northern Worcester hills and Monadnocks of southern New Hampshire. Rain may begin to change back to snowfall on early Saturday morning from west to east, as the secondary low pressure areas passes the region. And the midlevel low begins to redevelop off of the coast. Had the block not eroded as much and allowed the primary to penetrate as high up in latitude as it did, this mid level redevelopment could have limited the change to rain, but it still may aid in a period of snow showers on Saturday afternoon all of the way to the coast before precipitation tapers off entirely. First Call: Initial Threat Assessment Issued on Friday, December 9 at 12pm: Final call will be issued on Thursday-

First Call: https://easternmassweather.blogspot.com/2022/12/major-long-duration-winter-storm-likely.html Final on Thursday-

He is due for hell to pay.

Yea, it would suck if my luck ran out. Wouldn't want that

God, I can't wait for the opportunity to troll the ever-living shit out of other locales.

The NAO is negative, not that it changes anything. The block recedes just enough to allow the primary to last into the Great Lakes, which not only advects mid level warmth more aggressively, but allows the secondary SLP to hug the coast more closely, which cooks the coastal plane with onshore flow.

That's a Kev question frame lol

Hopefully Xmas isn't ruined snowwise...first holiday season that my oldest knows what is going on and I expected some snow. This is why I melted yesterday...not because I think the season is ruined or anything. Sucks. Absolute cannot catch a break

Nah, I'm past that with this...just focused on the forecast.

There is our Dec '96 lite.

I think that is less of a threat this time around because the PAC is changing.

Working on that now..

Yes, and its about to erupt if I don't pull off a white xmas this year.

Methuen can't even do fake cold well anymore That was the one thing that my locale still excelled at in terms of winter haha

I was about to post that....part of the reason why we can't get the snow deeper onto the CP.

Not sure why I didn't radiate....I am usually one the cooler spots.

Hopefully it trends a bit more for Kev.....but I am completely uninvested as far as MBY...let that go on Sunday.

I knew we would get one like that this month...lets get it out of the way now, while there is till time to recover prior to Xmas.

06z GFS gave Kev like an inch, tops...it was mainly good for N ORH co.

23.5 for the low here....fresh snowpack FTW out west.

Hr 186 is still long range in my book....medium range is like day 5-6.

Ditto...

Yea, guys have a shot, but you need a good day today.

It's been over for 2 days...let 'er go, folks...

I'm going to look into my crystal ball and guess that the euro sucked again lol Crickets....