40/70 Benchmark

It is, but its a different process than the traditional SSW....its happening due to lower proceccess and working up into the strat, so the impacts are felt more quickly since its beginning in the troposphere rather than the strat and downwelling.

I'll have to note that in my post-season analysis...didn't specify in real time.

Troposphere feeding back into strat?

Yea, I noticed that...what is drivinf this?

They seldom produce immediately....like folks have been saying, wait until the tropics begin to align with what is going on at the pole.

EURO AI is pretty pants-tenty all the way around......Thursday is like 3-4" from I 84 N & W, next weekend another 6-8" outside of 495, and then a big dog next week.

PV looks pretty split to me....I think the failure is in assuming that 3 feet of snow should instantaneously apprear in our driveway.

Yea, morale of the story is that they were both nuciance variety inconveniences that sucked.

The NAO has is so nuanced...there are like 6 different calculations and the orientation/shape of the heights can have drastically different implications on the pattern. Good luck to anyone trying to soley utilize a numerical index derivative of it in a forecast.

I got an like 1.5" on Feb 2, so probably something similar.

You should change your handle to wpc lol

The piles along my driveway are like 4-5'.

This remainds me of alot of that Sunday night, Feb 2 event.

That is the window...after this weekend.

Yea, he will probably have a net gainer and I may even...just saying I don't see it as a KU.

I think SWFE will be the name of the game until the tropics become aligned with the pole....ie these will be messy systems. Now, that doesn't mean it can't trend more favorably/colder, but I don't anticipate this ending up a pure east coast snow event.

I like the period from around the 20th onward.

Mine are actually getting pretty high....

This is what I meant....right now we have the tropics in conflict with the pole, but shortly beyond mid month, that will no longer be the case....huge potential.

I couldn't care less...just a window for me to finish my blog.

I would not necessarily say that.

Active Pattern Set to Continue into Mid Month Tropics & The Pole Initially Conflict There were two assertions made by Eastern Mass Weather with respect to the month of February, and the fact that they have both come to fruition is making for some challenging forecasts with respect to storm tracks because they reality is that they both conflict with one another. Maritime Continent Forcing to Remain Prevalent Throughout First Half of Month Currently the MJO is in phase 6 and approaching phase 7 at a fairly strong amplitude, both of which tend to favor lower heights in the west and greater heights in the east. Note the shift to the east of the east coast ridging and the building of higher heights in the west, which serves as a prelude to the changes that will grow more prevalent beyond mid month. While intuitively one may suggest that this promotes in inland track of east coast cyclones, that is not always the case, as is the cast with storm number one on Tuesday. Note that the system is forecast to pass south of the area and out to sea. despite the east coast ridge. However, if there were more of a trough on the east coast, the wave could potentially "dig" more, which could allow it to amplify and track further up the coast. Thus the more precise way to articulate this is that Maritime continent forcing is simply more unfavorable for major east coast winter storms because the east coast ridging that it promotes is hostile in a multitude of ways. However, tropical forcing does not operate in a vacuum, and there other global influences that can dictate the pattern. Namely, the higher latitudes. Ensuing Polar Vortex Split Will Play A Role In addition to a return to Maritime continent forcing and west coast troughing, the other Eastern Mass Weather postulation that is coming to fruition this month is a major disruption of the polar vortex, which will take place early this week. Not only will the disjointed polar vortex lobe supply antecedent cold air masses in advance of storm systems, but it will also act to foster the development of higher heights around the pole, which will only grow more prominent and represent added resistance to inland tracks towards mid month. While this next storm system on Thursday is an example of Maritime continent forcing mitigating an east coast storm opportunity via higher heights allowing for a more inland track, the aforementioned antecedent cold will also be evident. There is likely to be a few inches of snowfall across at least the interior prior to ending as sleet and rain. Cold will become more prevalent and there will be added resistance to inland tracks of low pressure systems as the month of progresses. A potentially major storm next weekend looks to at least deposit several inches of snowfall across the area prior to any mix or change to sleet and rainfall. Beyond mid month tropical forcing will begin to augment the building of heights near the pole as the MJO approaches phase 8. Stay tuned for First Call for the Thursday system tomorrow night and more update on the potential weekend system throughout the week.

Thoughts moving forward this week/month. https://easternmassweather.blogspot.com/2025/02/active-pattern-set-to-continue-into-mid.html

Downsloping probably plays into it....buts it not the elevation, per se....

Forecast for Weekend Snows Too Aggressive Dry Air Mitigating Factor Clearly the forecast for this weekend's snows was not one of the better efforts from Eastern Mass Weather, as the 6-10" and 5-8" forecast ranges ended up verifying as 5-8" and 3-6". The short answer as to why this was the case is that the encroachment of the drier air from the south, as discussed in the Final Call, was both faster and more aggressive than expected. This acted to essentially put an end to accumulating snowfall by around dawn on Sunday, as opposed to lingering throughout much of the morning. There were some subtle warning signs amongst guidance that snowfall could be a slightly less prolific than forecast as a direct result of less proficient snow growth. Lift and Moisture Less Than Ideally placed Within Snow Growth Region Here is data derived from the NAM forecast sounding for Lawrence, MA during yesterday's storm. Note how the maximum area of lift and moisture was not colocated with the -12 to -18c snow growth region, which is the ideal thermal range within the atmosphere for moisture and lift to combine for the optimal production of snow flakes, which of course accumulate the most efficiently. While this data was considered, it was obviously not weighted heavily enough into the forecast. The reason forecasting is so difficult is because not only is it incumbent on the forecaster to complete an exhaustive review of the data, but its also crucial to determine how heavily two weight each piece of data and when to disregard. Final Grade: C+