What systems should (not) have been classified?

[404UserNotFound]

The recent formation of Pablo and Rebekah in the Atlantic leads me to wonder: what systems should have been classified that, for whatever reason, weren't? (Or, if you prefer Type I errors, what systems shouldn't have been classified that, for whatever reason, were?)

To start us off, here is a system from the tropical Atlantic in late September 2010:

It's not the strongest of candidates for classification, but if it had been classified, it might have beaten out Tropical Storm Marco for smallest tropical cyclone on record. (More information on this particular system is available here.)

I'm not limiting this to just the Atlantic, though, so feel free to post other examples from around the world. Do try to avoid bashing any agencies that classify or monitor TCs, as they have their reasons behind their decisions; merely expressing disagreement is enough.

[Sciencerocks]

invest 90l 2014



invest 92l 2014




invest 95L 2014





invest 97L 2014




invest 98L 2014



Seriously, 2014 had quite a few nameable systems and had quite a bit of strength overall. But because of the reality these systems weren't upgraded 2014 is laughed at and peered with 2013 and 2015! Lets just say I wouldn't have been able to control my bashing of the nhc in 2014. Sorry.

[TheAustinMan]

In early October 1997 a storm developed near the Azores and tracked eastward, developing quite a bit of convection around a well-organized center of circulation. It eventually made landfall near Gibraltar and entered the western Mediterranean Sea, though it had lost most of convection at that point. Here's an image from when convection was most robust:

5.2MB. Source: Satellite data ordered from NOAA CLASS and processed using NOAA CoastWatch


There was in fact a second system that developed in this region of the northeastern Atlantic later the same month, moving through the Azores before making landfall on the northern Portuguese/Spanish border. It too had an organized convective pattern and was arguably a tropical cyclone, developing an eye-feature in the process. I'll see if I can fetch an image of when it made landfall on the Iberian Peninsula, but here are two images of it east of the Azores:

10KB. Source: Satellite data from NOAA CLASS and processed using NOAA Weather and Climate Toolkit


1.1MB. Source: Satellite data from NOAA CLASS and processed using NOAA Weather and Climate Toolkit

[MarioProtVI]

I have a few instances:

* Colin 2016 was bound to be discussed here, and while I do believe it was a brief TS as it was entering the Gulf before degenerating into a trough, had the POTC system been implemented a year earlier it would have never gotten a name bc of its structure and would bust a la 10L a year later.
* Olga from this year should not have been classified IMO. Was already merging with the front as it was being initiated and the strongest winds were behind the cold front which was not associated with the storm at all. Also not to mention it was only a TC for 6 h according to BT.

[1900hurricane]

In late November 1990, amidst an already active Pacific in both Northern and Southern Hemispheres, one more system may have slipped through the cracks. Active systems in the WPac at the time were Typhoons Owen and Page, which went on to become rare simultaneous category 5s. The SPac also had Cyclone Sina, which isn't in best track as a category 5 but probably be. However, east of Owen and across the equator from Sina was a large disturbance that may have gained enough organization to be classified as a TC, although no agency did so. It's a little difficult to tell if it is actually worthy with the imagery I have access to, but it was at least large enough to apparently interact with Owen, moving northwards out of the near-equatorial latitudes while Owen simultaneously slowed down and took a dive to the SW, dropping below 10ºN. It clearly wasn't anything intense, but I do lean towards it being a missed TC.

[Sciencerocks]

I believe Olga was upgradable 12 hours before they upgraded it and was probably a tropical storm by 5am and a depression about 6-12 hours earlier. The front was no where near the center and it had a clear warm core when it was upgraded so that argument isn't very strong.

Even at landfall and as it was approaching the coast it still had a warm core based on rig and surface observations so the front didn't really attach even then. One could make an argument for a tropical storm landfall with this storm.

[Sciencerocks]

Here's another good candidate! Invest 98L of 2018.

[aspen]

Here's another good candidate! Invest 98L of 2018.
https://imagizer.imageshack.com/a/img921/5130/TZvCpx.gif
https://imagizer.imageshack.com/a/img924/5892/ndljbW.jpg

https://imagizer.imageshack.com/a/img923/8034/rpXEZt.gif
https://imagizer.imageshack.com/a/img922/9653/kvR9zd.gif
https://imagizer.imageshack.com/a/img924/4590/O2frsn.gif

If I’m not mistaken, 98L came from the remnants of Florence after they emerged off of the New England coast.

[MarioProtVI]

Here's another good candidate! Invest 98L of 2018.
https://imagizer.imageshack.com/a/img921/5130/TZvCpx.gif
https://imagizer.imageshack.com/a/img924/5892/ndljbW.jpg

https://imagizer.imageshack.com/a/img923/8034/rpXEZt.gif
https://imagizer.imageshack.com/a/img922/9653/kvR9zd.gif
https://imagizer.imageshack.com/a/img924/4590/O2frsn.gif

If I’m not mistaken, 98L came from the remnants of Florence after they emerged off of the New England coast.

It actually came from the mid-level remnants as the surface circ of Florence had already dissipated over the NEUS. I think if it was classified it would’ve been a regeneration of Florence rather then Kirk (which was the next name since Joyce was already active), since the NHC has counted regeneration of a previous storm from a MLC before, such as Lee 2017.

[Ptarmigan]

Looks like 2014 may have been more active than previously thought.

I am not surprised some go undetected.

[TheAustinMan]

There's a whole collection of Mediterranean tropical and tropical-like cyclones that should probably be entered into the global tropical cyclone database. Some of the intriguing swirls that come up from time to time are often light on convection and very short-lived, but there are some stout examples that are probably very clear, well-organized, and convectively active warm core storms that deserve as much attention (if not more, due to their possible human impact) as their open-basin, north Atlantic counterparts that do get named.

Here's one of the more well-known cases from October 1996.

2.1 MB. Source: Ordered from NOAA CLASS and processed in NOAA CoastWatch.

[EquusStorm]

Oooh I LOVE this subject. Super fascinating stuff. Right off the top of my head 92L from last month one could almost make a case for...



And I could probably argue about multiple tropical storms this year being judgment calls (still unsure about Olga, mainly; usually something that lasts only 12 hours isn't classified) not to mention a few subtropical storms lately that seemed to barely meet criterion (Leslie's initial STS phase comes to mind with rather sparse convection) but lemme dig into my saved satellite archives and see what else I can come up with.

I'll second that 98L last year after Florence was a big one; the most extremely egregious case I can recall recently, and I think could have been classified more so than many marginal subtropical systems in recent decades even despite their hesitation due to scatterometer being a little unsure.

The October 9 2011 Florida storm (93L) is often mentioned when this subject comes up though there are debates.

A few recent cases that probably did NOT warrant classification but came VERY close and might still be as good a case as our most marginal classified tropical cyclones-

The tropical wave NE of where Nate developed in 2017 almost produced a tropical depression/storm in the Florida Straits had shear been weaker, but there were questions about being completely closed off and depth of convection; still awfully close.



95L in Sept 2013 came very close to becoming a tropical depression off the Texas coast before it was carried east with a front... and the remnant vorticity persisted for a few days unlike most weak systems.



Another 95L, last year, in the Gulf during Florence's landfall never really fully closed off in the Gulf but once it went ashore it maintained an organized at least mid level spin for days and well arranged convection, would've absolutely been our FIFTH simultaneous tropical cyclone in the Atlantic if it had 12 more hours over water... reminds me very much of Imelda this year just didn't have that extra burst of time

[1900hurricane]

The recent formation of Pablo and Rebekah in the Atlantic leads me to wonder: what systems should have been classified that, for whatever reason, weren't? (Or, if you prefer Type I errors, what systems shouldn't have been classified that, for whatever reason, were?)

To start us off, here is a system from the tropical Atlantic in late September 2010:
http://cimss.ssec.wisc.edu/goes/blog/wp-content/uploads/2010/09/100924-25_g13_vis_atl_swirl_anim.gif
It's not the strongest of candidates for classification, but if it had been classified, it might have beaten out Tropical Storm Marco for smallest tropical cyclone on record. (More information on this particular system is available here.)

I'm not limiting this to just the Atlantic, though, so feel free to post other examples from around the world. Do try to avoid bashing any agencies that classify or monitor TCs, as they have their reasons behind their decisions; merely expressing disagreement is enough.

The WPac had one of these from July 13-19, 2013 as well. I would tend away from classifying this particular case due to its struggle to maintain convection, but the persistence of the feature is surely fascinating.



“Midget” tropical cyclone over the West Pacific Ocean?

[DioBrando]

What about Lake Huron?
Would have been named Isidore, I think.

[NessFrogVenom]

I know it's been like two years since anyone has said anything, but Odette 2021 (Atlantic) is like another Colin (2016) but worse.

[Europa non è lontana]

In the "should be classified" column, I'd like to propose a small cyclone which appeared to be tropical or subtropical in nature on the 24th of November 1982, west of Dakhla, Western Sahara.

[Sciencerocks]

In the "should be classified" column, I'd like to propose a small cyclone which appeared to be tropical or subtropical in nature on the 24th of November 1982, west of Dakhla, Western Sahara.

https://i.imgur.com/xKOiFqO.png

Looks like a hurricane!

[Ptarmigan]

In the "should be classified" column, I'd like to propose a small cyclone which appeared to be tropical or subtropical in nature on the 24th of November 1982, west of Dakhla, Western Sahara.

https://i.imgur.com/xKOiFqO.png

Looks like a hurricane!

That is what I am thinking too. Looks like a midget hurricane.

[Europa non è lontana]

A further contribution -

an unclassified, very small-scale system with organised and consistent convection lasting for around two days around the 20th and 21st of November, 1983, which dissipated after landfall on mainland Portugal. Attached are visual and IR loops of the system. It traversed waters of 16-18C and likely had a warm or neutral core.



https://i.imgur.com/Nibl35p.mp4 Visual

https://i.imgur.com/MZdumWc.mp4 IR

I would be interested to hear opinions. Personally, I believe it is a system that met the definition of a subtropical storm, but obviously I am not an expert and more qualified eyes are needed to make a definitive judgement.

[Hurricaneman]

How about the nor’easter that went up the east coast on December 23/24 1994, was at one point IMO an 85 to 90 mph hurricane at one point, landfalling on Long Island/Southern New England