Suptropical Storm 1 (Upgraded in Pre-season Reanalysis)

[cycloneye]

Wikipedia already has it.



https://en.wikipedia.org/wiki/2023_Atla ... ane_season

[CrazyC83]

That uses the provisional Invest track, which is all we have for an operational perspective. We don't know yet when it became a STS, or when it became a remnant low again. I personally would have gone with a fully tropical classification, but that was just my own thought.

[cycloneye]

That uses the provisional Invest track, which is all we have for an operational perspective. We don't know yet when it became a STS, or when it became a remnant low again. I personally would have gone with a fully tropical classification, but that was just my own thought.

I guess, the TCR will have all the details.

[LemieT]

I remember looking at all of the available evidence wondering what the reason was for it NOT being upgraded... Hindsight is 20/20 I suppose.

[Old-TimeCane]

Perhaps this means that what would have been Idalia for the 2023 season now becomes Harold, so we manage to avoid the I curse for once

Take that Mother Nature!

Or it could go the other way. It might have been Jose, but now will be Idalia.

[aspen]

https://twitter.com/philklotzbach/status/1656679083995004929

Why aren’t they calling it Arlene? It’s not like any other name-able systems have formed or are about to form. It doesn’t seem like there’s anything to stop them from retroactively giving STS-1 a name.

[Teban54]

https://twitter.com/philklotzbach/status/1656679083995004929

Why aren’t they calling it Arlene? It’s not like any other name-able systems have formed or are about to form. It doesn’t seem like there’s anything to stop them from retroactively giving STS-1 a name.

Probably because the primary reason for tropical cyclones to be named (and the historical reason why naming started in the first place) is for clarity in informing the public about upcoming storms. Since this storm has already happened long ago, there's no longer a need to give it a name retroactively, especially as the impacts don't seem severe enough that people will be talking about it for ages.

Same reason why NHC didn't name the December 2013 subtropical storm Nestor.

[cycloneye]

After the upgrade, AL012023 starts the 2023 season with 2.2 ACE units.

[Hammy]

https://twitter.com/philklotzbach/status/1656679083995004929

Why aren’t they calling it Arlene? It’s not like any other name-able systems have formed or are about to form. It doesn’t seem like there’s anything to stop them from retroactively giving STS-1 a name.

Probably because the primary reason for tropical cyclones to be named (and the historical reason why naming started in the first place) is for clarity in informing the public about upcoming storms. Since this storm has already happened long ago, there's no longer a need to give it a name retroactively, especially as the impacts don't seem severe enough that people will be talking about it for ages.

Same reason why NHC didn't name the December 2013 subtropical storm Nestor.

1991 hurricane that formed from the Perfect Storm event was similarly not named, despite nothing following it, though that is an even more interesting case given to my knowledge, it was intentionally not given operational advisories to avoid media confusion

[cycloneye]

[Dean_175]

As many of you may remember, there was a warm seclusion in January off the coast of the US that had some characteristics of a subtropical cyclone. The original extratropical low brought cold conditions as far down as south Florida. I remember lows in the 40s in SFL, wintery southeast US, and snow up in New England from this system. However, after bringing this cold airmass to the south, the frontal bands to the east began to wrap up and the system developed a warm core and some deep convection. I understand the NHC reasoning for reclassification but I am honestly surprised by the upgrade. They operationally issued an advisory saying that the airmass in which it formed was "too cold" for it to meet the definition despite having detached from the frontal boundary and supporting deep convection. I agreed with that perspective. It is hard to mentally think of a system as being subtropical after delivering some of the coldest air of the year to the south Florida simply because the warm sector wrapped up and formed some convection. The air temperatures in the center were lukewarm at best and there had clearly been some extensive mixing with the non-tropical colder airmass of the north. Temperatures were in the low 60sF at the core. This is low enough to feel subjectively "cold" to a lot of people. I understand that the 1993 perfect storm formed from a nor'easter but temperatures in the core were much warmer. You can thus easily make that case that the '93 system formed within a tropical/subtropical airmass. I personally feel like the original assessment of "formed in a cool air mass" was accurate, because that is overall what happened. The impact of the storm to the US and Nova Scotia was mostly similar to what you find during a non-tropical system and intuitively, I storm that brings some of the coldest air of the year to Florida and then forms a short lived warm seclusion after occlusion is not subtropical. Thoughts?

[Hammy]

I understand that the 1993 perfect storm formed from a nor'easter but temperatures in the core were much warmer. You can thus easily make that case that the '93 system formed within a tropical/subtropical airmass. I personally feel like the original assessment of "formed in a cool air mass" was accurate, because that is overall what happened. The impact of the storm to the US and Nova Scotia was mostly similar to what you find during a non-tropical system and intuitively, I storm that brings some of the coldest air of the year to Florida and then forms a short lived warm seclusion after occlusion is not subtropical. Thoughts?

Air masses can modify as they move over the Gulf Stream, as tends to happen often with systems of subtropical/extratropical origins, so the conditions they had produced over land days earlier is not pertinent to what the conditions are at the time it forms. Regarding the bold in particular, an important distinction is that the 1993 system was frontal it's entire lifespan, where this was not (hence the subtropical designation) and was also producing snow during the same period--had it, accompanied by light upper winds, meandered over the Gulf Stream for several days, it too would have had an opportunity to transition to a subtropical system.

Karl in 1980 and the 1991 Perfect Storm show it is relatively uncommon, but not impossible, for systems to form entirely within colder airmasses--essentially a tropical/subtropical cyclone within a larger extratropical cyclone.

[JetFuel_SE]

I understand that the 1993 perfect storm formed from a nor'easter but temperatures in the core were much warmer. You can thus easily make that case that the '93 system formed within a tropical/subtropical airmass. I personally feel like the original assessment of "formed in a cool air mass" was accurate, because that is overall what happened. The impact of the storm to the US and Nova Scotia was mostly similar to what you find during a non-tropical system and intuitively, I storm that brings some of the coldest air of the year to Florida and then forms a short lived warm seclusion after occlusion is not subtropical. Thoughts?

Air masses can modify as they move over the Gulf Stream, as tends to happen often with systems of subtropical/extratropical origins, so the conditions they had produced over land days earlier is not pertinent to what the conditions are at the time it forms. Regarding the bold in particular, an important distinction is that the 1993 system was frontal it's entire lifespan, where this was not (hence the subtropical designation) and was also producing snow during the same period--had it, accompanied by light upper winds, meandered over the Gulf Stream for several days, it too would have had an opportunity to transition to a subtropical system.

Karl in 1980 and the 1991 Perfect Storm show it is relatively uncommon, but not impossible, for systems to form entirely within colder airmasses--essentially a tropical/subtropical cyclone within a larger extratropical cyclone.

I believe Alpha in 2020 was another example of this.