March 13th ... west Atlantic bombogenesis type low clipping SE New England, more certain ...may be expanding inland

[Typhoon Tip]

Okay ...so there's enough teleconnector support, along with off-and-on guidance depictions for greater impact to justify monitoring and discussion. 

First off ...to be clear and up front: this is not a high confidence for strike scenario.  I am not sure what other Met's coveted feelings are on this (or skilled hobbyists alike..); I, however, figure about 40% chance and that's a percentage in flux.

I did originally compare this system to last January's southern stream bomb that partially phased as the whole flow instructed it to lift (probably) just too far east to be truly memorable/historic, but far enough west to still clock the region.

There are differences here to be more on the poor side of a total analog ... however.  For one, the surrounding medium back in January was still being plagued by very fast flow and effectively 'too much of a good thing' with deep cold heights so deep that the surrounding balanced flow was utterly screaming in rage ... That all matters, because phasing was not really capable of happening in a raging one-eyed monster SPV construct such as that... 

One thing I am noticing here over all, regardless of model actually ... the issue is that there is a wave-frequency problem between the N/stream and S/streams.  The S/stream is moving too fast ...out -pacing the N/stream, which can't thusly phase.  It's like ... a comet orbiting the sun:  a pure phase is the comet crashing into the sun (pure N/stream subsume); a near miss phase or failures altogether are accelerating close passes, where in this case (completing the metaphor) the object (S/stream impulse) is sling shot around the N/stream gravity well...  interesting.

This is just observationally what appears to be happening for me. I don't know if this correctable ... or whatever, but.. the southern stream impulse is definitely outpacing the N/stream even in this more prodigious impact 12z NAM idea ... There is in fact only partial phasing in the sense that the N/stream is helping to dictate the track of the S/stream system, but it's really not capturing it at all. (Edit - the correction may come from correctly anticipating the western N/A ridge ironically) A more robust complexion with that would transitively influence the flow between 100 and 70 W longitudes over mid latitudes...effectively slowing it and everything in it, down..thus, allowing the diving N/stream to do it's magic... ).

I have a funny feeling ... don't shoot me, but I suspect this Euro run is going to be more substantial here in a couple hours.  Just a hunch -

 

[Typhoon Tip]

Other than these points, the only real difference between the 06z and the 12z NAM runs is that the southern stream impulse is somewhere between 200 and 300 miles farther alone in longitude comparative. That's a big deal?  because the prior run being back west means that it is more so in destructive wave interference with the N/stream, which come hell or high water is coming down - that much is lock-step keyed into the +PNA spike well advertised to date.  We ain't gettin' outta dat much-a dis.  The repositioning of that little amount goes from destructive to modest constructive interference there. 

[JC-CT]

11 minutes ago, Typhoon Tip said:

Other than these points, the only real difference between the 06z and the 12z NAM runs is that the southern stream impulse is somewhere between 200 and 300 miles farther alone in longitude comparative. That's a big deal?  because the prior run being back west means that it is more so in destructive wave interference with the N/stream, which come hell or high water is coming down - that much is lock-step keyed into the +PNA spike well advertised to date.  We ain't gettin' outta dat much-a dis.  The repositioning of that little amount goes from destructive to modest constructive interference there. 

Yeah Tip, it was really close to getting out ahead of the northern stream so the northern stream can dig behind it and allow it to turn up the coast. Not much more needed from that depiction.

[JC-CT]

2 hours ago, JC-CT said:

As much as this appears on life support, there is still a critical piece here that is up in no man's land.

Easy to say now that there are two pieces of 12z guidance that are confirming my thoughts, but these canadian no man's land shortwaves tend to be undermodeled in strength by the satellites and often will trend stronger almost up until go-time.

[Typhoon Tip]

The Boxing Day storm ...so it is dubbed, was an event that seemed to come 'storming' back in short range guidance.

There was another, more recent ...I wanna say three years ago?  more of an open wave that managed to go from flat and almost non-identifiable in the mid range, all the way to about an 18 hour lead warning event... solid 9-12" occurred.. 

This system reeks as being a short duration correction opportunity -whether it avails, we shall see. 

JC',  not sure if this is worth much but that ICON model trended favorably...albeit small amount. If it did so the same for three or four cycles, everyone east of ALB would be in...

[NorEastermass128]

Holy smokes at the 12z GFS. Big hit!  And so close to a huge hit!

[Damage In Tolland]

One more bumpy west and it’s a blizzard 

[weathafella]

1+ qpf inside 128.

[NorEastermass128]

Blizzard for Harwich, MA, USA?

[Bostonseminole]

GFS needs more work

[JC-CT]

GGEM is a scraper but a big adjustment from 0z.

[Bostonseminole]

oops was looking at the 6z.. 12z much better wow..

[CoastalWx]

GFS was a big hit. Canadian a much better look for sure.

[Typhoon Tip]

Okay ... so, we are establishing a trend ?  ...worth questioning.  I still also hunch the 12z Euro may be more interesting...

That said, this is still more a SE zones impact as it looks now, obviously.  But this is clearly a scenario in a state of marinade -

[HoarfrostHubb]

2 minutes ago, Bostonseminole said:

oops was looking at the 6z.. 12z much better wow..

I was gonna say...   But let’s see if it can show some consistency

[TheCloser24]

12z JMA 974mb near Nantucket. Wow.

[Bostonseminole]

winds should be impressive down at the cape with this one also

[CoastalWx]

JMA was just south of the BM.

[JC-CT]

4 minutes ago, CoastalWx said:

JMA was just south of the BM.

Not seeing it. Looks NW of it.

 

[JC-CT]

Trying to figure out a possible analog for this one...not a perfect match, but there are some similarities to Juno (Jan 15).

[Typhoon Tip]

Ho ho man... That GGEM solution really cannot physically ( as in math ... ) interact the N and S/streams there any closer without that S/stream falling into the "event horizon" ... 

[Typhoon Tip]

1 minute ago, JC-CT said:

Trying to figure out a possible analog for this one...not a perfect match, but there are some similarities to Juno (Jan 15).

yeah... CIPS may actually fun for morbid curiosity...

 

[Typhoon Tip]

jma is about 1 degree S of the BM there...  but, that's well close enough to safely assume everyone east of the Berkshires are in the threat envelope so it's quibbling over irrelevance -

[JC-CT]

2 minutes ago, Typhoon Tip said:

jma is about 1 degree S of the BM there...  but, that's well close enough to safely assume everyone east of the Berkshires are in the thread envelope so it's quibbling over irrelevance -

I'll go ahead and retract my previous statement. The JMA is dead nuts on the benchmark.

[Hoth]

9 minutes ago, JC-CT said:

Trying to figure out a possible analog for this one...not a perfect match, but there are some similarities to Juno (Jan 15).

I like the idea of a last minute correction like that one. That was a classic "not happening, James" system where spacing and other subtle problems looked to skunk a great opportunity, but then it came roaring back in one modeling cycle and ushered in three weeks of epicosity. I agree with you that the n/s vort could well be underdone given its source region. We've seen these things trend stronger on a few occasions this year.

[JC-CT]

Just now, Hoth said:

I like the idea of a last minute correction like that one. That was a classic "not happening, James" system where spacing and other subtle problems looked to skunk a great opportunity, but then it came roaring back in one modeling cycle and ushered in three weeks of epicosity. I agree with you that the n/s vort could well be underdone given its source region. We've seen these things trend stronger on a few occasions this year.

Not just that, but the overall evolution. That one had a complete phase, although at this lead time some models were showing a similar evolution to the 12z GFS. The source region of the canadian s/w was similar as well.

[JC-CT]

Navgem is a scraper too, but like the GGEM it is a big adjustment from 6z.

[CT Valley Snowman]

Uncle went back east some from yesterday.  

[CoastalWx]

20 minutes ago, JC-CT said:

Not seeing it. Looks NW of it.

 

Hr 72

[rnaude241]

Any chance we rain down here? I hope not after all my good ju-ju I've put on this storm.