jbenedet

I mean, I get that. You’re talking 988 type low at the high end. It’s capped but at a slightly higher level imo, than the alternative. I just think more can go right, with a legit miller B, and much more can go wrong with a SWFE given the players.

I see a hybrid (late bloomer) in EPS and UK. GFS mostly SWFE. ukie most miller B like, GFS least, EPS in between

When the NAO is this negative, and flow is slow, I say let cyclogenesis work its magic off the east coast strong vort be damned. You’re more likely to get positive surprises than negative, so long as temps are supportive.

Yea that’s what’s getting it twisted—an us vs them scenario. NNE wants a SWFE (primary holds on indefinitely) whereas SNE and north Mid Atlantic want a legit Miller B. The snowfall outcome is very much capped (everywhere) at moderate scale outside of an outcome that results in a weak primary that quickly transfers to Del Marva and then phases with the Northern Stream Shortwave, somewhere south of the Cape.

Again. Similarities to 12/12/22

I still believe the prevailing issue is the shortwave over Manitoba. There’s theories on what would help bring back a stronger storm—why not just look at the earlier runs which were outputting such solutions? What was the biggest change? The late phasing of the primary, which causes it to hang on later, and diffusing chance of a clean phase with the coastal. To my mind if you dampen this feature, and the primary fizzles sooner, you can get a dynamic cyclogensis —even with weak UL forcing—to occur given the slow flow over the western Atlantic. This wouldn’t be great for everyone of course, but it would give much higher totals to SNE and northern Mid Atlantic.

This reminds me a lot of the December 12 event. A more potent version.

The 6z EPS makes much more sense to me than the 12z GEFS. The GEFS is phase happy with the shortwave over Manitoba. But it could be correct. The result is much less clean; energy broadened rather than consolidated. QPF expectations should be 1/4 - 1/2 of the EPS-eque evolution. This shortwave out of a data sparce region is definitely adding to uncertainty. Am very curious to see EPS at 12z.

Freezing drizzle

If the deepest cold was advecting from the northern plains and central Canada behind it, I'd agree with your concerns - the primary will want to hang on, and bend back. But the airmass behind it is relatively quite warm.

I can see that. I mean when it comes to the wave inhibiting strength of confluence I try to focus on where the deepest (relative) cold anomalies are. If they are collocated with the confluence, out ahead of the amplifying wave--and within the sphere of its would-be warm sector-- that's a pretty damn good indication it will not be able to bend north, in the face of it, and quickly concede to an earlier secondary. This of course is conditional that the confluence is anchored, which is what we are looking at in this case, with a strong -NAO developing.

That's a good point. Possible though currently unlikely. But if what I believe to be a trend of Stronger block-->slower trajectory, that would increase the odds quite a bit vs the current guidance consensus on that aspect. Point of interest highest for eastern locations.

Some members with much less blocking? I mean, they are possible, but I don't see any reason to buy into those at the moment, given the trends and forecast teleconnections. That's just me. Then there are others that show more, hence the mean, with E trajectory.

We'll see. I believe this one will spread the love, "so to speak". Hit the areas hardest who have seen the worst snowfall deficits. I strongly doubt a persistence outcome. The significant -NAO alone says this event is quite different than the recent past, at least going back to mid December.

Yea that's the bite of this for Pike North. I mean there's no curling (bending back) as it hits the Atlantic, the strength of the block increases greatly from that point.

That's a sig block incoming, peaking right around this storm's closest approach. Strongest -NAO we have seen all season. Great for coastal SNE and Northern Mid Atlantic. Too much of a good thing for the northern folks, is my take.

We haven’t seen a similar pattern to this since early to mid December. We had our little CT crusher during that timeframe, even with warm climo.

12-18 is very much still on the table. I mean, don’t take my word for it, just read the GEFS and EPS verbatim.

The guidance right now, looking at MJO and NAO forecasts, both point to strengthening the -NAO block up until go time. Maybe these are wrong…? But when I see EPS and GEFS following those forecasts, as I do now, I’m hedging in favor of a stronger block in 5 days than what is currently being shown across guidance.

By CNE you mean pike north to NH/VT border? If that’s the case I think you’re going to see a sharp west/east gradient in CNE. Higher amounts west, Lower amounts east. I like NJ and LI better than most of CNE for this one. And def better than NNE. At least right now.

My *current* take on heavy snow probs. SNE > N Mid Atlantic > NNE

Good news is the strong -NAO block is real. The bad news is there is little arctic interaction and therefore we’ve seen a dampening in the solutions with time, due to the combination of these factors. The balance of this is certainly net positive for snow-starved SNE. Highest confidence that the axis of heaviest snowfall is in SNE, and increases as you move closer to the coast.

Can’t argue with this current guidance consensus inside 5 days. Best SECS chance for sub-forum this season, by far.

Sleet. Looks like 2”. Was probably closer to 3” before the sleet compaction.