Some (hopefully) clarifying thoughts regarding this "modeled" historic pig

[Typhoon Tip]

I am hoping this doesn't get lost in the din of the emotive threads on the matter -

The relay from the western Pacific (Prapiroon) is instrumental in getting the -EPO ridge built and in play - that EPO ridge then retrogrades S/SW and the PNA is caused to rise, pretty dramatically actually, as a direct result. The end result might be an ~ 2.5 SD rise in the index; together with an on-going -NAO puts a strong negative geopotential anomaly signal between the OV and the MA between D6 and D10.

Without the ingestion of a tropical entity, this signal alone is impressive and coastal cyclogenesis potential is hightened/favored. Folks in the business should be impressed by this potential alone, I feel, because I could see Appalatian snows perhaps involving the GL, and an impressive backside CAA (eventually) for the MA and NE regions. Typically, by the way, these types of phenomenon in October have a winter enthusiast-favorable correlation for DJF - but let's hold off from going there for now.

Whether we happen to see a well timed TC get caught up into the fray is entirely questionable - who knows - but that should be separate. Time will tell if this is a real hybrid threat, or just another typical autumnal modeled uber phase. We see this once or twice per Fall season, where the models (more typically the CMC) do this. You may recall some 9 days prior to the great December Nor'easter in 2003, the Canadian GGEM was at the time doing something oh too familiar to what is currently being portrayed - what is perhaps a tad disturbing is that so many guidance types are on board for so far in advance. However, what transpired back then was an impressive Nor'easter, with no ultimate involvement of a Caribbean tropical entity.

A Professor and I once noted to one another that often preceding some of Nature's bigger events, the signal tends to show up a longer model leads than is usually observed. This, as we presume, is/was because their dynamical presence in the atmosphere, even as emergent properties, shine just a little brighter than the typically muting capacity of the daily noise in the flow. I suggest there are not so subtle signals, the abrupt onset of the AB phase of the North Pacific is transmitting a teleconnection to the OV-MA that both does not need to involve a tropical system to be impressive, but is just such an emergent property.

I can just hear someone saying, "wow - big storm without there being a tropical system", as though that would be shocking. This statement is in hopes that if this all proves to be computer enhanced delusion, there is still an objective reason to be alerted to the possibility of coastal cyclogenesis.

That all said, yeah - it's amazing what's out there in the runs. In a sense, these runs remind me of a Perfect Storm subsuming scenario, only happening on the MA as opposed to 600 nautical miles seaward, then retrograding toward the coast. There is also a bit of a question as to an 1804 analog - but I think that's questionable. Either way, the impact of a 12z blend would be ...I hate to say, catastrophic and easily of historic nature. There's just no other way around that interpretation of these runs. Those that choose to bring that message to the public eye or ear, need to strongly word that there is a coastal storm threat showing up in the extended range; and should they choose to bring up tropical involvement, that needs to be done as an after thought and highly questionable. That can easily be achieved at this type of time lead without being a detriment to public awareness.

Conclusion: From where I am sitting there is a far more impressive signal for important East Coastal cyclogenesis alone, and whether some may find that less "entertaining", or boring, or allow that to affect them on a deeper level, that is all we really have and should be admired for its own rite. It's really an amazing thing to see an instructional ethos mapped out where a path to an EC storm has an origin from a half way around the world!

[csnavywx]

I am hoping this doesn't get lost in the din of the emotive threads on the matter -

The relay from the western Pacific (Prapiroon) is instrumental in getting the -EPO ridge built and in play - that EPO ridge then retrogrades S/SW and the PNA is caused to rise, pretty dramatically actually, as a direct result. The end result might be an ~ 2.5 SD rise in the index; together with an on-going -NAO puts a strong negative geopotential anomaly signal between the OV and the MA between D6 and D10.

Without the ingestion of a tropical entity, this signal alone is impressive and coastal cyclogenesis potential is hightened/favored. Folks in the business should be impressed by this potential alone, I feel, because I could see Appalatian snows perhaps involving the GL, and an impressive backside CAA (eventually) for the MA and NE regions. Typically, by the way, these types of phenomenon in October have a winter enthusiast-favorable correlation for DJF - but let's hold off from going there for now.

Whether we happen to see a well timed TC get caught up into the fray is entirely questionable - who knows - but that should be separate. Time will tell if this is a real hybrid threat, or just another typical autumnal modeled uber phase. We see this once or twice per Fall season, where the models (more typically the CMC) do this. You may recall some 9 days prior to the great December Nor'easter in 2003, the Canadian GGEM was at the time doing something oh too familiar to what is currently being portrayed - what is perhaps a tad disturbing is that so many guidance types are on board for so far in advance. However, what transpired back then was an impressive Nor'easter, with no ultimate involvement of a Caribbean tropical entity.

A Professor and I once noted to one another that often preceding some of Nature's bigger events, the signal tends to show up a longer model leads than is usually observed. This, as we presume, is/was because their dynamical presence in the atmosphere, even as emergent properties, shine just a little brighter than the typically muting capacity of the daily noise in the flow. I suggest there are not so subtle signals, the abrupt onset of the AB phase of the North Pacific is transmitting a teleconnection to the OV-MA that both does not need to involve a tropical system to be impressive, but is just such an emergent property.

I can just hear someone saying, "wow - big storm without there being a tropical system", as though that would be shocking. This statement is in hopes that if this all proves to be computer enhanced delusion, there is still an objective reason to be alerted to the possibility of coastal cyclogenesis.

That all said, yeah - it's amazing what's out there in the runs. In a sense, these runs remind me of a Perfect Storm subsuming scenario, only happening on the MA as opposed to 600 nautical miles seaward, then retrograding toward the coast. There is also a bit of a question as to an 1804 analog - but I think that's questionable. Either way, the impact of a 12z blend would be ...I hate to say, catastrophic and easily of historic nature. There's just no other way around that interpretation of these runs. Those that choose to bring that message to the public eye or ear, need to strongly word that there is a coastal storm threat showing up in the extended range; and should they choose to bring up tropical involvement, that needs to be done as an after thought and highly questionable. That can easily be achieved at this type of time lead without being a detriment to public awareness.

Conclusion: From where I am sitting there is a far more impressive signal for important East Coastal cyclogenesis alone, and whether some may find that less "entertaining", or boring, or allow that to affect them on a deeper level, that is all we really have and should be admired for its own rite. It's really an amazing thing to see an instructional ethos mapped out where a path to an EC storm has an origin from a half way around the world!

I've had more than a few conversations with fellow mets about this. The Superstorm fell into this category, for instance. The Groundhog Day Blizzard was another (off the top of my head here). Of course, I admit this could be an artifact of my perception.

[Brian5671]

Excellent writeup!

[Typhoon Tip]

06z GFS and the 00z GGEM underscore the central theme in this, in that there is a strong teleconnection for a negative geopotential anomaly from the OV-MA, long before there is the introduction of a happenstance TC that lurks too close to the "gravity well" - so to speak.

Don't get me wrong - that latter would be spectacular. But from a purely Meteorological perspective on things, the successful execution of a deep closure and focus for a L/W as these model runs show is important, and I think somewhat lost in the din of awe over having a TC involved.