ATL: KATE - Post-Tropical - Discussion

[ozonepete]

Thanks Luis. I missed that. Everything's happening so fast with this...

[ozonepete]

After watching the rgb loop for a while it looks like there are a couple of low level circs spinning around. Some of you already commented on the one that's exposed on the south side. I think there's another north-northwest of that one that's elongated a little. So basically it looks like it's still trying to consolidate one LLC from many as is the norm in the early stages. Has to be watched really closely though of course since we all know that little ones can spin up super fast.

edited to fix the spelling.

[Hammy]

Based on watching low cloud movement the swirl that's there formed about 18-19z, several hours after that ASCAT pass. This may get upgraded tonight if we get one tonight that doesn't miss it.

[cycloneye]

Before the sun goes here is last visible image that shows a exposed LLC.

[AutoPenalti]

It's moving rather quickly and it's decoupling. I don't see a TD tomorrow.

[blp]

Before the sun goes here is last visible image that shows a exposed LLC.

[]http://i.imgur.com/kFAOcPb.png[/img]

That is why ASCAT is not always accurate with such a small system. It clearly had a llc today under that convection. It may have a chance tomorrow when it should slow down as it rounds the high and hits the weakness.

[ozonepete]

It's moving rather quickly and it's decoupling. I don't see a TD tomorrow.

It can't decouple because it never coupled; that low level center was never completely under the MLC. And it now looks like that center may fade as the system is still producing multiple LLCs that are rotating around a broader MLC. There is a very good chance this will consolidate overnight since it is so small, over very warm water and shear will be very low. Many times when were all looking at a developing TC like this we all start watching every frame as if it were the only one that matters and forget that the system is moving into a very favorable environment. It's the environment that dictates what will happen.

[cycloneye]

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
700 PM EST SUN NOV 8 2015

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

Showers and thunderstorms associated with a small low pressure area
located about 60 miles east-northeast of Mayaguana in the
southeastern Bahamas continue to show signs of organization. Recent
satellite images indicate that the circulation has become better
defined since this morning, and only a slight increase in
organization of the system would result in the formation of a
tropical depression or tropical storm tonight or Monday. Interests
in the Bahamas should monitor the progress of the low since a
Tropical Storm Warning may be required for a portion of the central
and northwestern Bahamas tonight or early Monday. Regardless of
development, locally heavy rainfall and gusty winds are likely
over portions of the Bahamas during the next day or so. An Air Force
Reserve hurricane hunter aircraft is scheduled to investigate this
system Monday morning.
* Formation chance through 48 hours...high...80 percent
* Formation chance through 5 days...high...80 percent

$$
Forecaster Brown

[rickybobby]

They didn't even talk about it in wesh at 6pm.

[ozonepete]

The southern LLC is hanging tough. If that were to hang on and produce convection the initial path would be further south than the models since that LLC is moving west-northwest, not northwest. This is getting interesting.

[cycloneye]

00z Best Track.

As of 00:00 UTC Nov 09, 2015:

Location: 22.7°N 72.4°W
Maximum Winds: 30 kt Gusts: N/A
Minimum Central Pressure: 1010 mb
Environmental Pressure: 1013 mb
Radius of Circulation: 100 NM
Radius of Maximum Wind: 40 NM

[ozonepete]

Ok, so by that NHC fix they have that little LLC (Luis showed us a last minute visible close-up a little while ago) as the COC that we're following. Even at night it's easy to follow since there's no convection over it so far.

[northjaxpro]

Ok, so by that NHC fix they have that little LLC (Luis showed us a last minute visible close-up a little while ago) as the COC that we're following. Even at night it's easy to follow since there's no convection over it so far.

Yes ozonepete apparently that is the LLC being tracked right now.

[Weatherwatcher98]

Interesting Little system, if there was not a front coming east.

[ozonepete]

So unusual! Now it's developed banding at low levels which I don't remember ever seeing before on a developing TC but you can clearly see it on this RGB satellite image. Also, the Convection is beginning to build and move towards the low level center. I would definitely not take my eye off this if I lived in the northern Bahamas...

[floridasun78]

The southern LLC is hanging tough. If that were to hang on and produce convection the initial path would be further south than the models since that LLC is moving west-northwest, not northwest. This is getting interesting.

why say may get interesting???

[Hammy]

That huge convective band seems to be making up for the convection being blown off earlier and helping the circulation wind up, and it's on the side where the upper flow is coming from which makes me wonder if that's the source of said flow.

[ozonepete]

The southern LLC is hanging tough. If that were to hang on and produce convection the initial path would be further south than the models since that LLC is moving west-northwest, not northwest. This is getting interesting.

why say may get interesting???

Because even though I still think it can never make it to Florida, it could come much closer than I thought it would. Smaller systems are much harder to forecast. Look at what Joaquin did - so many surprises.

[ozonepete]

Biggest negative for further development right now is a pretty big lack of symmetry. I suspect that's because it went through a narrow band of heavy south to north shear earlier today that sheared the entire circulation from SE to NW. But it looks like it's recovering from that. If the convection gets over that little LLC and the convective blob gets more circular I would expect some RI. If not it will probably just get to a medium TS before the big approaching long-wave trough catches it and shoves it northeastward.

[SouthDadeFish]

The NHC could easily call 94L a tropical cyclone at 03Z if they wish. There is a vigorous LLC with convection moving closer to the center. The persistent convection this morning spun up a vortex that is only now apparent because the convection got sheared off. This is fun to watch. Rapid tropical cyclogenesis is not unprecedented for small cyclones such as this with a nearby upper level potential vorticity (PV) anomaly forcing ascent over the TC.