ATL: HERMINE - Post-Tropical - Discussion

[stormhunter7]

btw, recon hit what should be the center at 16:50:30Z Coordinates: 18.733N 64.500W Acft. Static Air Press: 988.5 mb Acft. Geopotential Hgt: 177 m (581 ft) Extrap. Sfc. Press: 1008.7 mb (29.79 inHg)

[HurriGuy]

As long as the LLC keeps pulsing the convection near south and southeast side of it, I don't see this going anywhere.

[Siker]

from the 00z ECMWF, it did not have a stacked system until Friday 00z. I don't know what everyone was expecting today. So far the model hasn't missed a beat. Had the system decoupled at 18z today pretty severely

Yes, the divergence between the Euro and GFS starts most notably in 24 hours when the Euro has upper level vorticity redeveloping over the low level vorticity maximum while the GFS keeps any upper level vorticity displaced 200 miles to the east.

[xironman]

There is something going on out there

Code: Select all

Product: Air Force Tropical RECCO Message (URNT11 KNHC)
Transmitted: 24th day of the month at 17:14Z
Agency: United States Air Force
Aircraft: Lockheed WC-130J Hercules with reg. number AF98-5308
Mission Purpose: Investigate fourth suspect area (flight in the North Atlantic basin)
Mission Number: 2
Observation Number: 10

Mandatory Data...

Observation Time: 17:05Z on Wednesday
Coordinates: 18.8N 64.0W
Location: 138 statute miles (222 km) to the E (79°) from San Juan, Puerto Rico (U.S.).
Pressure Altitude: 180 meters (591 feet)
Flight Level Wind: From 160° at 54 knots (From the SSE at ~ 62.1 mph)
- The above is a spot wind.
- Winds were obtained using doppler radar or inertial systems.
Flight Level Air Temperature: 22°C (72°F)
Flight Level Dew Point: 18°C (64°F)
Weather (within 30 nm): Shower(s) (continuous or intermittent precipitation - from cumuliform clouds)
Turbulence: Light
Conditions Along Flight Route: In and out of clouds
Radar Capability: Yes
Mean Sea Level Pressure (MSLP): 1010 mb (29.83 inHg), extrapolated

Additional Data...

Estimated Surface Wind: From 160° at 50 knots (From the SSE at ~ 57.5 mph

[RL3AO]

Looks like some northern shear over the main convection. Did the convection lag behind the anti-cyclone?

[setexholmes]

That last euro run has a few people here in Port Arthur a little worried. Looking forward to the next run and what it will tell us. I know it's a long way out but I may go pick up some supplies today.

[Tireman4]

That last euro run has a few people here in Port Arthur a little worried. Looking forward to the next run and what it will tell us. I know it's a long way out but I may go pick up some supplies today.

Still have a long ways to go, much information to be ingested into the models, lots of factors to consider. That being said, it is never "not" a bad time to update your hurricane kits.

[JaxGator]

Looks like some northern shear over the main convection. Did the convection lag behind the anti-cyclone?

Yes. It's a bit west of the convection. It shows up good on the shear maps.

[tolakram]

If you step through the shear maps you can see it has backed off a little in the last 3 hours.

The models have shown this struggling until very near Florida so this is expected, but I don;t blame people for doubting it base on experiences from the last few years.

http://tropic.ssec.wisc.edu/real-time/w ... oom=&time=

[Weatherboy1]

With those kind of winds, I'm actually somewhat surprised they haven't just gone ahead and called this thing a TD. We've seen relatively sheared systems like this get named/designated before. A few naked swirl/displaced convection-type systems off the coast of FL, particularly at the beginning of a couple of seasons, come to mind. Obviously, a lack of convection over the center and probably some worry about naming the thing only to have it fall apart a few hours later are probably to blame. But seems to pretty much meet the requirements for a TD here ...

[psyclone]

A vigorous disturbance rolling across a few thousand miles of tropical/subtropical waters in late August is likely to eventually find a sweet spot and form. The shear looks to abate in a couple of days and the system will have had a chance to clear Hispaniola (even skirting the north shore would disrupt inflow)...so we just need to do more of what we always do...hurry up and wait. I would not be the least shocked if a strong TS or category 1 blasts across south florida on its way to the Gulf.

[Hammy]

I'm jumping back on the no-development train with this, I still have a bet riding on nothing coming of it. The shear was not forecast by any of the models to be this strong at this point and it's essentially being shredded. Basically Erika 2015 redux.

Looks like some northern shear over the main convection. Did the convection lag behind the anti-cyclone?

It moved WNW-NW while the anticyclone kept moving straight west by the looks of it.

[fci]

finally finding west winds..

Yeah, I don't think there is debate to be had that there is at least one circulation present, I feel its more a question of whether or not the organisation justifies it right now...

With that being said, if this is 100 miles from the coast of the USA...it gets an upgrade...if its at 40W, no upgrade.

I respectfully disagree with your assertion.
If it meets the criteria, they upgrade; no matter the location.
With no convection around a swirl and convection really hundreds of miles south, this is a classic tropical wave albeit a strong one.

[StormHunter72]

I'm jumping back on the no-development train with this, I still have a bet riding on nothing coming of it. The shear was not forecast by any of the models to be this strong at this point and it's essentially being shredded. Basically Erika 2015 redux.

check out remnants of fionna. playing a big part.

[SoupBone]

I'm jumping back on the no-development train with this, I still have a bet riding on nothing coming of it. The shear was not forecast by any of the models to be this strong at this point and it's essentially being shredded. Basically Erika 2015 redux.

I would love for you to be right, but I just don't see it. However, I noted a page or so back that the shear is increasing in the GoM according to the last few updates on the shear charts. Is that what the models are sniffing at for keeping this in check?

[OntarioEggplant]

finally finding west winds..

Yeah, I don't think there is debate to be had that there is at least one circulation present, I feel its more a question of whether or not the organisation justifies it right now...

With that being said, if this is 100 miles from the coast of the USA...it gets an upgrade...if its at 40W, no upgrade.

I respectfully disagree with your assertion.
If it meets the criteria, they upgrade; no matter the location.
With no convection around a swirl and convection really hundreds of miles south, this is a classic tropical wave albeit a strong one.

A wave isn't closed off, a low is. If recon can close a low, then it isn't a wave anymore.

[alienstorm]

Here is a shot from the San Juan Radar

[fci]

from the 00z ECMWF, it did not have a stacked system until Friday 00z. I don't know what everyone was expecting today. So far the model hasn't missed a beat. Had the system decoupled at 18z today pretty severely

People are just understandably anxious. Models showing possible TC hitting South Florida in 4 days and then maybe a Cat 3 in GOM bathrub; makes people impatient to actually see "something".

[AutoPenalti]

Shear increasing... This thing is dying. NHC should lower its chances now. I don't see it making it.

[StormHunter72]

Here is a shot from the San Juan Radar

looks like an open wave at best.