ATL: TROPICAL STORM BILL (03L)

[KWT]

Yep forward speed is a big issue and its why Derek was quite annoyed by the 0z runs earlier, because the models are just stupidly slow in the first 72hrs.

Put it this way the ECm takes 66hrs to move about 10 degree, thats about 10kts average speed from now on in which is probably way too slow given its current forward speed.

[Rainband]

Ok, still awake. 00Z GFS takes it right across southern Florida 3 days behind what will be Ana then toward the mid Gulf Coast. So south Florida could be hit by a TS, maybe a hurricane then 3 days later get hit by a big and powerful hurricane. Oh, and the GFS has one a few days behind 90L, too, heading in the same direction.

i dont like that model it's like frances and jeanne.

[KWT]

Somewhat similar but more like a direct one-two punch on the GFS, though to be fair some of the other models are further north today, but there is some uncertainty aobut forward speed...

Anyway convection not quite as strong as last night though not enough of a degeneration to stop it from being upgraded, should still have TD3 soon.

[wxmann_91]

No, what I was saying is that the ECM slows down the storm because of the weakness (as all storms do when they are about to recurve), and a faster/slower initial speed won't affect the fact that it will slow down when it comes to a weakness in the ridge (assuming the ECM is right and the weakness is as strong as its progs).

[cheezyWXguy]

Somewhat similar but more like a direct one-two punch on the GFS, though to be fair some of the other models are further north today, but there is some uncertainty aobut forward speed...

Anyway convection not quite as strong as last night though not enough of a degeneration to stop it from being upgraded, should still have TD3 soon.

true, its not quite as cold as it was maybe, 2 hours ago, but its also becoming more symmetrical. thunderstorms are now feeding in from the backside of the circulation, and the structure is still improving. Typical of developing storms, convection pulses. This thing, Im pretty sure is a td now and will be called such by 5am/11am at latest.

[KWT]

Yeah BUT its moving too slow on the ECM, what we are saying is 90L may already be nearly past the weakness by the time it opens up and therefore its not going to turn out like the ECM shows because it won't be in the right position for that to happen.

As I said before 90L has to average about 10kts from now onwards for the ECM to be right, which is possible but given its still moving about 16kts not all that likely.

Also remember the weakness only starts to form after 48hrs, till then the high is pretty solid. So if 90L is too quick it won't take the full recurve but instead only move towards the WNW.

[KWT]

Yeah it still looks good and the overall structure is what you'd expect from a developing tropical depression.

[cheezyWXguy]

No, what I was saying is that the ECM slows down the storm because of the weakness (as all storms do when they are about to recurve), and a faster/slower initial speed won't affect the fact that it will slow down when it comes to a weakness in the ridge (assuming the ECM is right and the weakness is as strong as its progs).

ok that's true if there's a weakness, I'll buy that. But there's no weakness yet. My thinking is that the model suite thinks td2 is dead and that whats out ahead of 90L is a developing weakness, instead of what it really is, a developing tropical cyclone. That is enough to throw the models off from what could really happen. Yeah, it could very well go north, but nothing at this time suggests recurvature yet. We need to just wait for the next set or 2 of models to come in, look for a trend, and see how td2/ana affects the track/intensity of 90L. Those are the 2 dominant factors that will play on the storm in the near future.

[bvigal]

15/0615 UTC 12.0N 32.0W T2.0/2.0 90L

[wxmann_91]

No, what I was saying is that the ECM slows down the storm because of the weakness (as all storms do when they are about to recurve), and a faster/slower initial speed won't affect the fact that it will slow down when it comes to a weakness in the ridge (assuming the ECM is right and the weakness is as strong as its progs).

ok that's true if there's a weakness, I'll buy that. But there's no weakness yet. My thinking is that the model suite thinks td2 is dead and that whats out ahead of 90L is a developing weakness, instead of what it really is, a developing tropical cyclone. That is enough to throw the models off from what could really happen. Yeah, it could very well go north, but nothing at this time suggests recurvature yet. We need to just wait for the next set or 2 of models to come in, look for a trend, and see how td2/ana affects the track/intensity of 90L. Those are the 2 dominant factors that will play on the storm in the near future.

The first half of your post is incorrect. There's a weakness in the ctrl ATL all right, due to the large ULL in that area (ironically this same ULL is providing the upper divergence that's reinvigorating TD2/Ana). It's not that they're handling Ana badly (it's a small storm anyways so effects in the short term should be minimal anyway), it's just that they're not having a good handle on the upper level features in the data-sparse region of the central-eastern Atlantic.

Now the second half I actually agree with sorta. I just wish there was consensus now.

[Stormsfury]

90L is well on its way to becoming a tropical cyclone and a large circulation envelope at that (partial aid with a monsoon trough further south). Some equatorial outflow is being established and an overall twist to the cloud pattern is emerging in the last few hours.

It's no longer a matter of if with 90L but when later today that the upgrade will occur. I would expect by 11 am Saturday. 90L has an ominous appeal to it.

[bob rulz]

I'm surprised it wasn't upgraded this advisory...I see no reason why it shouldn't be. Satellite estimates support a tropical depression and the convection isn't going to poof anytime soon.

[Rainband]

90L is well on its way to becoming a tropical cyclone and a large circulation envelope at that (partial aid with a monsoon trough further south). Some equatorial outflow is being established and an overall twist to the cloud pattern is emerging in the last few hours.

It's no longer a matter of if with 90L but when later today that the upgrade will occur. I would expect by 11 am Saturday. 90L has an ominous appeal to it.

I agree Nice to see you dude!!!

[stormchazer]

I think looking at 90L now, if it was within 24-36 hours of striking a landmass, the NHC would probably have upgraded earlier on a special advisory, much less at 5 AM. Maybe they are waiting for the visuals though in East Atlantic they would have them by now I guess.

[bvigal]

looks pretty good

[Aquawind]

Yep the center looks to be under the convection now and some deep is refiring at the moment.. it won't be long.

[Derek Ortt]

new GFS looks to be just a touch to the SW of the 0Z

[Thunder44]

Latest QS image:

http://manati.orbit.nesdis.noaa.gov/dat ... Bas112.png

[Derek Ortt]

looks like a shear axis there and not an LLC... need to check the ambiguites

[cycloneye]

Derek,GFS doesnt know that Ana exists,why is that?