Remnants of Nadine (14L)

[Ed Lizard]

So if it's not subtropical, it's... a warm seclusion? Warm occlusion (see latest ascat)? Just another warm cored gale?

I thought this was a joke, but just aw the Hart reference "deadly but rare" a warm core seclusion in NYC regional 1938 thread, and thought only polar cyclones could do that. Apparently I was wrong.

Cliff Notes version of how a tropical cyclone could do this?

http://www.americanwx.com/bb/index.php/topic/36755-the-great-hurricane-of-1938/

[thewxmann]

I'm rooting for this to get to the Mediterranean.

[Mike.Ventrice]

I'm sure its pain to forecast for a system that is rather weak with the track forecast being so highly uncertain. I still remain skeptical that Nadine ever becomes extratropical within the forecast period unless it shows increased evidence of recurving. While the deterministic solutions have shifted eastward, the ensembles are still nearly split down the middle in regards to a West vs. East track. This is probably one of the hardest track forecasts of the year, even beating out Debby.

You have no idea what we've been going through here at HS3. Every forecast briefing I give is the same tune "Highly uncertain track" or something along those lines. Some may disagree, but it's sad this is the only TC we've truely sampled numerous times during the campaign.

[Ground Scouring]

I didn't even Josh's lips move in any of your last 3 posts.

G-L-O-B-A-L W-A-R-M-I-N-G

=

This year

There. I said it

Late 19th century + mini-Ice Age > 2010s crappy seasons

[phil882]

Nadine is looking rather tropical right now.

[NYCSuburbs]

Nadine is looking rather tropical right now.

Up to 60% chance of redevelopment as of 2 AM, certainly looking better... Nadine becoming subtropical, then post-tropical while stalling close to the Azores and eventually redeveloping would probably label it as one of the stranger storms of the year IMO. At least there appears to be a better consensus on the track compared to a few days ago.

[Mike.Ventrice]

Uh oh....

[dan11295]

up to 90% at 8 am.. Just checked the 6z GFS and doesnt do anything exciting with it. Has it wander west, north and east a bit before merging with a front.

[Mike.Ventrice]

up to 90% at 8 am.. Just checked the 6z GFS and doesnt do anything exciting with it. Has it wander west, north and east a bit before merging with a front.

The global hawk found a 70 kt 900 hPa wind.. Hurricane Center should get this data soon and most undoubtly will bring back Nadine today as either a strong TS/low grade Cat 1

[bluewave]

The strong Atlantic blocking pattern really threw the models a curve ball in trying to guess Nadine's track.

It's a rarity to have a TC tracking westward from a position NE of 30/30.

[phlwx]

The global hawk found a 70 kt 900 hPa wind.. Hurricane Center should get this data soon and most undoubtly will bring back Nadine today as either a strong TS/low grade Cat 1

60 mph at 11.

[dan11295]

Time to update the title..lol. NHC takes it west now and makes it a Hurricane again.My guess is the GFS scenario is most likely. West then north followed by frontal merger,

[PSUBlizzicane2007]

This storm is filled with lols.

[Amped]

^{Half of it was absorebed by the front yesterday. This is similar to how Ivan regenerated.}

[bluewave]

Nadine has a chance to join the 20 days or more club. The Euro maintains the very slow motion right into October.

...LONG-LIVED NADINE BECOMES A TROPICAL STORM AGAIN...

http://www.aoml.noaa...d/tcfaq/E6.html

[phil882]

^{Half of it was absorebed by the front yesterday. This is similar to how Ivan regenerated.}

The low level circulation associated with Nadine was never absorbed. This is a much different evolution than what you were describing with Ivan.

I think Nadine is a good example on how broken and subjective the subtropical/post-tropical/tropical definitions can be. At what point do you call a system post-tropical because it does not have enough convection? Nadine was never "devoid" of convection at any point during its life cycle, its just the convection was low topped and didn't reach as high up into the troposphere as deeper tropical convection might.

[NYCSuburbs]

The low level circulation associated with Nadine was never absorbed. This is a much different evolution than what you were describing with Ivan.

I think Nadine is a good example on how broken and subjective the subtropical/post-tropical/tropical definitions can be. At what point do you call a system post-tropical because it does not have enough convection? Nadine was never "devoid" of convection at any point during its life cycle, its just the convection was low topped and didn't reach as high up into the troposphere as deeper tropical convection might.

NHC's discussions prior to declaring it a post-tropical cyclone clearly highlighted the uncertainty with how to define Nadine. I'm not sure if it's significant enough to any post-season review to be done on it, although it is a great example of how subjective these definitions can be as you said.

[icebreaker5221]

Incredibly, today's 12Z Euro still has Nadine a distinct entity SW of the Azores at day 10 - Oct 3. Nadine formed Sep 7, and almost all of it's life was at least tropical storm (or subrtopical, or extratropical) strength. The record is San Ciriaco (1899) with 28 days at least TS strength. How awesome if a non-tropical crap storm like this overtook the record?

[Ground Scouring]

NHC's discussions prior to declaring it a post-tropical cyclone clearly highlighted the uncertainty with how to define Nadine. I'm not sure if it's significant enough to any post-season review to be done on it, although it is a great example of how subjective these definitions can be as you said.

Another classic case of such a conundrum was the classification of Erin 2007 over Oklahoma. The system was in a different synoptic environment than that of Nadine--trapped beneath a large-scale heat ridge as a mid-level shortwave reflection pulled it slowly NE--but the dilemma was similar: the system regenerated as an MCS and even developed a hurricane-like eye feature over land while producing sustained winds near 50-55 kt over the Oklahoma City metropolitan area. The NHC in its post-storm assessment, if I recall correctly, classified the system as a remnant low but did not deny its tropical links, though there was apparently a weak cold core aloft at 500 mb. But one person could argue that a weak cold core aloft, particularly with a system like Erin that is mainly in the low levels, does not necessarily preclude a tropical classification as outside factors such as adiabatic cooling and nearby synoptic features--such as the troughs in the case of recurving, transitioning extratropical cyclones--could influence the mid-level temperatures while the fluid processes involved in sustaining convection are not too distant from those of a classic tropical cyclone over water...namely, latent heat of condensation, particularly if a region has been saturated prior to the system, as OK was before Erin arrived. There are easily many cases I can imagine in which the normal rules of tropical-cyclone formation may be complicated by external factors. At any rate, we may eventually reach the point where typical ideas of TC formation may need to be redefined somewhat as in cases like Ivan 1980 (a cold-core low near the Azores that became a near-major hurricane, somewhat like Gordon and Michael this year).

[phil882]

Incredibly, today's 12Z Euro still has Nadine a distinct entity SW of the Azores at day 10 - Oct 3. Nadine formed Sep 7, and almost all of it's life was at least tropical storm (or subrtopical, or extratropical) strength. The record is San Ciriaco (1899) with 28 days at least TS strength. How awesome if a non-tropical crap storm like this overtook the record?

The 00z run does the same thing, with no signs of recurvature at day 10. While I'd peg that to be a highly unlikely solution, this entire atmospheric pattern across the Atlantic basin that allowed for Nadine to reach this position is highly unusual. TCs of any type at any time in this region of the Atlantic basin are HIGHLY usual, as evidence through this IBTrACS graphic, which shows a very low to non-existent density of TCs in the 30-35N and 20-30W corridor. That leaves us in uncharted waters, so its not surprising that Nadine has been a very difficult to forecast system thus far, and that does not appear to be changing anytime soon. As long as the anomalous riding to its north and west holds, the system is unlikely to recurve. Both the ECMWF and GFS suggest this could finally relax to a more zonal flow in the day 7 range, but a lot can change before now and then.

[icebreaker5221]

Incredibly, today's 12Z Euro still has Nadine a distinct entity SW of the Azores at day 10 - Oct 3. Nadine formed Sep 7, and almost all of it's life was at least tropical storm (or subrtopical, or extratropical) strength. The record is San Ciriaco (1899) with 28 days at least TS strength. How awesome if a non-tropical crap storm like this overtook the record?

Sry, Nadine formed Sep 11. Still a long-lived system and especially rare for something already beginning to recurve the day it formed.

The 00z run does the same thing, with no signs of recurvature at day 10. While I'd peg that to be a highly unlikely solution, this entire atmospheric pattern across the Atlantic basin that allowed for Nadine to reach this position is highly unusual. TCs of any type at any time in this region of the Atlantic basin are HIGHLY usual, as evidence through this IBTrACS graphic, which shows a very low to non-existent density of TCs in the 30-35N and 20-30W corridor. That leaves us in uncharted waters, so its not surprising that Nadine has been a very difficult to forecast system thus far, and that does not appear to be changing anytime soon. As long as the anomalous riding to its north and west holds, the system is unlikely to recurve. Both the ECMWF and GFS suggest this could finally relax to a more zonal flow in the day 7 range, but a lot can change before now and then.

Good points Phil about the historical precedence of the location of Nadine. What's worse is that any regional analogues we do have had an extremely different synoptic setup (e.g. Becky 1962, Charley 1992), typically with a ridge to the east and a trough to the west resulting in NEward motion. Here we have the opposite synoptic setup, and hence a storm motion opposite climo.

[PSUBlizzicane2007]

Incredibly, today's 12Z Euro still has Nadine a distinct entity SW of the Azores at day 10 - Oct 3. Nadine formed Sep 7, and almost all of it's life was at least tropical storm (or subrtopical, or extratropical) strength. The record is San Ciriaco (1899) with 28 days at least TS strength. How awesome if a non-tropical crap storm like this overtook the record?

Just as a remark, Hurricane Ginger holds the record for most consecutive days as a tropical cyclone and is the longest-lived cyclone in the satellite era.

[icebreaker5221]

Just as a remark, Hurricane Ginger holds the record for most consecutive days as a tropical cyclone and is the longest-lived cyclone in the satellite era.

True. We really don't know the exact dates and times of the genesis and dissipation of San Ciriaco with the kind of certainty we have with Ginger.

[Derecho!]

Just as a remark, Hurricane Ginger holds the record for most consecutive days as a tropical cyclone and is the longest-lived cyclone in the satellite era.

Isn't it Hurricane/Typhoon John?

[aslkahuna]

Ginger lasted 29 days while John lasted 30 days.

Steve

[wxmx]

In the 12z Euro, Nadine keeps missing trough after trough after trough...NE should keep an eye on it.

[PSUBlizzicane2007]

Isn't it Hurricane/Typhoon John?

I was talking about the Atlantic. John is the longest overall.

[Amped]

In the 12z Euro, Nadine keeps missing trough after trough after trough...NE should keep an eye on it.

Good thing, otherwise what would there be to bore us for the next 10 days?

[phil882]

Nadine looking better today, with more deep convection near the center.

As has seemed to be the trend in most of the modeling this year, Nadine is responding to stronger than forecasted ridging in the modeling. If you remember from last week, the guidance was essentially split between a recurve out into Europe vs. a westward track back in the Atlantic basin. The stronger ridging prevailed as the upper level trough was not able to pick up Nadine. The models (the GFS in particular) continues to underestimate the amount of ridging that is expected over the next 48-120 hours, which has significantly slowed down the forward progression of Nadine that was expected to take place this week. A stronger ridge in place has effectively blocked a more northward motion over the next 2-4 days as the system meanders south and continues to remain a nuisance TC while perhaps intensifying over the slightly warmer waters located south fo 30N.

http://www.atmos.albany.edu/student/abrammer/GFS_forecast/500vr_hgt/

[phil882]

Probably the best satellite presentation Nadine has had its entire lifespan with a well defined eye and convection (albiet moderate) rotating in all quadrants.