ATL: Ex COLIN - Discussion

[x-y-no]

Huh ... if that ASCAT graphic is right, I'm kind of at a loss as to what I'm seeing on IR2.

[CrazyC83]

If that scan is to be believed, a center relocation seems to be underway.

[Extremeweatherguy]

Well

Very interesting ASCAT pass Ivanhater. If that is correct, then the center is either further west than we thought (under the blob of convection), or it may be relocating there. That would definitely help in terms of strengthening if the LLC was located there.

[Air Force Met]

Well

Well...if the LLC IS way out there...then the MLC is back at 44...and that is no bueno.

It would change the ball game in a couple of ways. 1) moves the track way to the west...and 2) increased the likelihood of this opening up into a wave.

[wxman57]

Well

http://www.knmi.nl/scatterometer/ascat_ ... 3_00_5.gif

That image indicates no LLC, just a wave axis. I doubt there's an LLC where the green dot is. It would help if the scan went a bit farther west. Remember, NHC is positioning a "center" near 44.1W, not 46W. If it was near 46W, then it's moving at closer to 20 kts to the west.

[ozonepete]

this thing rmeinds me alot of Bonnie in appearance doesn't it? What's up with the hostile conditions this year? Granted its only Aug. 2...

These tropical sytems are no match for what is out there right now eating them alive.

It's very hostile, reminds me of 2006. Maybe no major hurricanes this year?

The overall combination of major factors pointing to a large number of tropical cyclones this season is nothing like 2006. There is much less shear right now, just for starters. And the model trends show less shear as we go forward. Just remember it's only August 3rd.

[Dean4Storms]

I think everyone should remember what wxman57 said about not looking at the blob of convection to determine the movement. The center of circulation still looks like it's moving west-northwest as far as I can tell. Just watch the RGB or visible loops. And the nose (forward edge) of that big ridge that it's riding under is moving forward even faster and will soon merge into the overall Bermuda high, and then this low may very well slow down a little. So I don't see anything wrong with the NHC forecast right now.

One thing though ozonepete, if you remember ever since the Invest to 91L the models have continued to turn this more NW immediately on every run and so far it continues 280ish. Eventually you have to see what is actually taking place and realize the models are missing something and I think it might be much like Wxman57 said, the LLC may not be completely closed off and thus the lack of deepening which would mean the easterlies are more in control of this systems path.

[ozonepete]

Well

http://www.knmi.nl/scatterometer/ascat_ ... 3_00_5.gif

That image indicates no LLC, just a wave axis. I doubt there's an LLC where the green dot is. It would help if the scan went a bit farther west. Remember, NHC is positioning a "center" near 44.1W, not 46W. If it was near 46W, then it's moving at closer to 20 kts to the west.

Who'd a thought we'd miss QuikScat.

[Gustywind]

I think the trend is more westward from what we are seeing, this has to be due to the TD being kept in check convection wise from the dry air to its north and the fast forward speed which is indicative of a strong ridge!!!! I just don't see it gaining the latitude that for the past several runs all the models have been latched onto.

I would stay aware of this if I was in the Lesser Antilles and even the Windwards!!

I'm aware. I've been seeing this trend all day. Fact is that it's going too much west and that the function of westward and northward over time is not happening. It's going too much west. It's not gaining latitude enough to become a fish.

You're right i have noticied that too my friend. Pretty suspicious... Too much excitement as i pointed yesterday night meanwhile TD4 was not even born! But much of the posters were saying proudly FISH FISH. If this stay souther than 15N tommorow this time all the Leewards could be in trouble and if the trend is more west and even iportions of the Windwards Islands. Let's hope that TD4 begin (finally) tonight or tommorow morning its real turn to the west/north/west and NorthWest because for the moment TD4 does not want to move away as a FISH

[CrazyC83]

I definitely think the old center is dissipating. But a new center seems to be forming under the convection.

[Dean4Storms]

I think we got an open wave now with a MLC!!

[Air Force Met]

Very interesting ASCAT pass Ivanhater. If that is correct, then the center is either further west than we thought (under the blob of convection), or it may be relocating there. That would definitely help in terms of strengthening if the LLC was located there.

Not really. There is a definite spin on the IR that is 120 nm east of that location. If that's the case...this no longer has any stacking. It would have to rebuild its core while fighting the old core.

But...to me...it seems hard to streamline a closed LLC from that image. Even though it doesn't go far enough west...it gives some clues. TO me it seems this is showing a sharp wave axis...not a closed LLC. If it is closed...it is barely closed...and by barely...I mean BARELY.

[Vortmax1]

I think we got an open wave now with a MLC!!

I also believe that...but I was told not to talk about ......certain things.

[Gustywind]

I definitely think the old center is dissipating. But a new center seems to be forming under the convection.

Where? More west?

[CrazyC83]

I definitely think the old center is dissipating. But a new center seems to be forming under the convection.

Where? More west?

WNW of the old center, under the deep convection.

[ozonepete]

I think everyone should remember what wxman57 said about not looking at the blob of convection to determine the movement. The center of circulation still looks like it's moving west-northwest as far as I can tell. Just watch the RGB or visible loops. And the nose (forward edge) of that big ridge that it's riding under is moving forward even faster and will soon merge into the overall Bermuda high, and then this low may very well slow down a little. So I don't see anything wrong with the NHC forecast right now.

One thing though ozonepete, if you remember ever since the Invest to 91L the models have continued to turn this more NW immediately on every run and so far it continues 280ish. Eventually you have to see what is actually taking place and realize the models are missing something and I think it might be much like Wxman57 said, the LLC may not be completely closed off and thus the lack of deepening which would mean the easterlies are more in control of this systems path.

I agree, Dean, that the models are missing something. But I think I know what it is and it's pretty classic: they can't handle the direction of a weak tropical low that may very well be re-centering as it goes, especially because it's moving so fast. But they don't need to since they use overall synoptic conditions to forecast the track when the center is ill-defined and I don't see any major changes in those conditions right now that would change the forecast direction. I still often disagree with their strength forecasts, but on track they are so accurate now that it's rare to see them blow it, especially at high speeds.

[Nimbus]

looping till 1:15 UTC the IR loop looks like the center passed through 13.1N 44.5W.
There is a new burst of convection just SW of that coordinate.

Its been steaming along at about 280 all day and although its still a weak system I'm concerned for the islands.

[Ivanhater]

Well

Well...if the LLC IS way out there...then the MLC is back at 44...and that is no bueno.

It would change the ball game in a couple of ways. 1) moves the track way to the west...and 2) increased the likelihood of this opening up into a wave.

I actually didn't even notice the green dot under the blob when I first posted, I just noticed all the east winds running through where the center was supposed to be.

[Gustywind]

[Dean4Storms]

I think the 0z model runs might be all over the place.