jbenedet

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.

Yes, but again, 850's could cooperate here (much more likely than not), all the way up to h500. It's the BL, up to 925 where the problems arise. And even though this 12z GFS depiction shows snow in SE NH on this, I am hard selling the clowns here, with a strong southeasterly fetch out ahead. This IS very similar to the problems we had seen during other favorable windows, earlier in the season.

While we will have a strong -NAO at this time, I believe there's a high risk that this one, ironically, hooks up with the SE ridge, because of the overwhelming pacific. It's not apparent at all at H5; H5 looks generally good. But the warm 850 temps and surface flag high chance of ptype issues. The highest probs is a decent track, but "no cold air". This looks similar to the recurring issue we have had in the recent past, and it's a much different look than this week, with cold anomalies throughout the eastern CONUS and SE Canada.

Yea we were sucking subsidence up until 7. Good snow growth so I imagine ratios are good in those areas. I suspect a lot of what has fallen is gone by tomorrow.

A coating only on cold surfaces. Roads just wet. Probably gone in the afternoon. Yet another early spring type snowfall.

20/8 for a low at DAW. About normal. No wind, full sun. Should be a nice day by mid Feb standards.