ATL: INVEST 92L - Discussion

[Ubuntwo]

brand new ascat..

I would say that is pretty darn close for a STS .. if not already a STS>

https://i.ibb.co/P57htSV/Capture.png

https://i.ibb.co/1KDnr7Y/Capture.png

https://www.weathernerds.org/satellite/sessions/GOES16_1km_swir_202005300255_23.25_31.75_-61.75_-47.75_swir1_hgwy_warn_latlon_ascata_ascatb_ascatc_weathernerds.png

Winds are well past the classification criteria... but it's still all tied up in that trough.

thats what makes it a "Sub Tropical Storm" we needed a well defined circ..

Subtropical storms have a shallow, asymmetric warm core, that's what differentiates them from fully tropical cyclones. they still usually need to be cut off from other features

[Aric Dunn]

Winds are well past the classification criteria... but it's still all tied up in that trough.

thats what makes it a "Sub Tropical Storm" we needed a well defined circ..

Subtropical storms have a shallow, asymmetric warm core, that's what differentiates them from fully tropical cyclones. they still usually need to be cut off from other features

they can and have formed directly underneath a ULL... which overtime that ULL weakens..

[Aric Dunn]

It is pretty clear we have a well defined circ. sheared but that is normal for a SUB tropical storm. it should be upgraded ASAP.

[Ubuntwo]

It is pretty clear we have a well defined circ. sheared but that is normal for a SUB tropical storm. it should be upgraded ASAP.

https://i.ibb.co/HV0s4KF/11223344555.gif

Yeah, the low cloud deck is increasing around the center and it's clearly become more defined. Classification is up to the nhc's discretion as always.

[EquusStorm]

I think subtropical storms have a relatively lenient classification standard lately compared to purely tropical systems so yeah wouldn't be shocked to wake up to Cristobal. IF the circulation stays well defined at the surface and IF convection doesn't start dying off.

[chaser1]

Who doesn't enjoy seeing another record fall? On the other hand, what is the relavent merit to "a new record" when it's simply a result of what today's Meteorologists choose to define or classify what yester-year's Meteorologists would not? I contend that back in the day when Hurricane Forecasters had to walk barefoot in the snow just to make it to work (okay, perhaps not LOL), these same mid-Atlantic anomalies were no less prevalent. Only a very few mid/upper level low's that hung around for days "might" have shed their associated frontal appendages and actually acquired a sufficient closed LLC and greater extent of tropical characteristics to then possibly warrant being tagged a sub-tropical storm. But hey, if we're willing to really lower the bar then I'll bet we could easily dig up a good 10 or more cold core N. Atlantic spin-ups each year to guarantee using up an entire alphabet per 12 month season!

I don't know... call me "old school", but this just doesn't deserve to be given a name. Call it baroclinic, call it a Gale, call it for dinner reservations for two. But for the love of all things tropical, please GOD don't permit NHC to call it Cristobal

[supercane4867]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 AM EDT Sat May 30 2020

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Special Tropical Weather Outlook issued to discuss the area of low
pressure over the central Atlantic.

1. A broad area of low pressure is located over the central Atlantic.
The associated shower activity has become better organized during
the past several hours, and the wind circulation has become
somewhat better defined. Additional development is possible today
and tonight, and a subtropical depression could still form while
the system moves generally northward. Further development is not
expected after that time due to unfavorable environmental
conditions. The next Special Tropical Weather Outlook will be issued
by 9 AM EDT Saturday, or earlier if necessary.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 5 days...medium...60 percent.

Forecaster Beven

[Hammy]

I don't know... call me "old school", but this just doesn't deserve to be given a name. Call it baroclinic, call it a Gale, call it for dinner reservations for two. But for the love of all things tropical, please GOD don't permit NHC to call it Cristobal

This looks fairly similar to Arthur (1996) on satellite and in fact is a tad stronger based on ASCAT.

That said, it really should've been upgraded at 11. That they've only upped the chances to 60% (medium range) and now with the circulation being almost completely exposed means they're more than likely not going to issue advisories--unless something drastic changes it's past the point which they'd bother.

[TheStormExpert]

It’ll be interesting to see if 92L will become Subtropical Depression #3 or Subtropical Storm Cristobal considering the past few STWO’s have mentioned it still could become a STD.

[Dean_175]

LLC is moving underneath the trough into a region of lower wind shear. Convection is also starting to wrap around to the southwest- with the main region of convection also becoming more defined and isolated. Classic subtropical storm setup. I think we could see a STD 3 or a STS Christobal by noon EDT.

ASCAT shows wind field is still somewhat of a mess though--circulation elongated and asymmetric.

[USTropics]

First visible imagery this morning. Has some wrapping up to do, but improving. Chances should increase this morning.

[USTropics]

The main inhibiting factor will be the inflow of dry air evident by the cloud structure and pattern:



This mixing process could prevent 92L from consolidating enough convective mass to efficiently lower pressure in one area to sustain an LLC. That will be the evolution to watch throughout the day. After 36 hours, model guidance shows an unfavorable environment for any weak/elongated circulation to persist (increased shear + low RH values):

[Siker]

Clear low-level vortex pivoting on the north end, the site of a convective burst for 12+ hours. I’m not confident in this getting designated because convective activity has continued to decrease and it’s really only got 24 hours to get its act together (and needs to hold together long enough to get classified).

[NDG]

Next!
I'm glad I didn't wasted my time with this Invest, I don't like tracking low pressures so close to a potent ULL, it takes a while to transition especially over SSTs only in the mid 70s.

[Dylan]

Next!
I'm glad I didn't wasted my time with this Invest, I don't like tracking low pressures so close to a potent ULL, it takes a while to transition especially over SSTs only in the mid 70s.

https://i.imgur.com/0abSj9k.jpg

Yep, doesn't look healthy at all.

[wxman57]

Up to a 60% chance the NHC will call this mess a subtropical depression or storm that will last 12 hours or less. Doesn't get more exciting than this!

My focus is on the Arabian Sea, where we have clients in the path of a possible strong TC on the west coast of India next week.

[TheStormExpert]

Up to a 60% chance the NHC will call this mess a subtropical depression or storm that will last 12 hours or less. Doesn't get more exciting than this!

My focus is on the Arabian Sea, where we have clients in the path of a possible strong TC on the west coast of India next week.

Where’s Bones!?

[Aric Dunn]

Overall it does not matter what it looks like. If dynamics of the system.make it a STS if should be upgraded regardless of how long it lasts. Skewed historical data helps no one.

The ULL will keep this a STS. Convection is sheared. But it is still a STS.

[cycloneye]

 https://twitter.com/pppapin/status/1266765170304364546

[NDG]

Not enough for an upgrade, IMO. It will be moving over SSTs in the low 70s tonight.