ATL: ISAAC - Post-Tropical - Discussion

[wxman76]

I personally have been leaning Euro all day and if the center is really that far south and not under the northern convection The Euro may very well score a Coup here putting SE Lousiana well into play. It is true with that convection moving due west the center must be south of it. Lets see if it wraps around enough to give us a really good fix on the center or well at least that one!

Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[KWT]

Tweet from recon itself:

"Radar analysis from #N42 shows a complex structure for #Isaac -- multiple circulation centers in a broad overall circulation."

Sorta confirms what others have said, a mess!!

[alienstorm]

http://img21.imageshack.us/img21/7491/isaacvv.png

This is where the center is..

[gboudx]

Tweet from recon itself:

"Radar analysis from #N42 shows a complex structure for #Isaac -- multiple circulation centers in a broad overall circulation."

Sorta confirms what others have said, a mess!!

That's cool that they tweet. What is the twitter handle?

[KWT]

you can clearly see the circ develop down there on radar.

http://flhurricane.com/imageanimator.php?137

You can see right at the end that new circulation form, looks like its sling-shotting the northern circulation around whilst the southern vortex slows down, as you and also recon have said, its still rotating around a middle point.

Here you go:

https://twitter.com/HRD_AOML_NOAA

[Tyler Penland]

In response to the center relocation, I really sincerely think, and have all day long, that it is trying to consolidate S/SW of the convection. I'm just a noob but just watching satellite loops over and over it looks like it is trying to take over.

Also it is noticeably elongated west to east now. From the rotational dynamics I would expect the center to consolidate a little eastward, not southwestward.

Since when has a hurricane done what it was supposed to/is expected to do....

[SunnyThoughts]

Tweet from recon itself:

"Radar analysis from #N42 shows a complex structure for #Isaac -- multiple circulation centers in a broad overall circulation."

Sorta confirms what others have said, a mess!!

That's cool that they tweet. What is the twitter handle?

https://twitter.com/HRD_AOML_NOAA

[psyclone]

With the models nudging west over the last few days, whats the chance SE La could come in play? Thanks

It's just too soon to tell. Keep watching. the storm is a solid week or perhaps more from louisiana should it head that way.

Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[shortwave]

http://geotest.tamu.edu/userfiles/222/allison.pdf

maybe somethin akin to this

[RL3AO]

With the models nudging west over the last few days, whats the chance SE La could come in play? Thanks

Oh yes. Some even think Texas could eventually come into play. While Florida is most likely at this point, areas further west can't be ruled out especially if the center redevelops further south.

[ConvergenceZone]

it probably should technically be downgraded but i doubt the NHC will do so in the interest of continuity. invert and ask yourself if this was classed as a TD now, how long until an upgrade? probably not long so the NHC is probably reluctant to downgrade just to upgrade 12 hours or so later.

That's what they said on TV earlier. That it very well could only be a tropical depresson but that the proximity to the islands will keep the downgrade at bay for now...
Of course if it looks worse in a few hours, then they may finally pull the downgrade trigger anyway...

[Shuriken]

My personal analysis of radar:

A: "NW center" ...the old, broad, pre-TD LLC formerly visible two days ago.
B: "SE center" ...surface vortex under eastern convection
C: mid-level center associated with last night's -85C blow-up. Appears to be finally waning.
D: apparent neutral center of system

The situation is evolving rapidly this evening:

Updated interpretations....

[ozonepete]

Here are real numbers from surface obs. Would put the center where I annotated.

[wxman76]

1003.9 mb pressure (extrapolated) at 13.900N 61.533W according to recon. lowest pressure I have seen yet.

[Emmett_Brown]

Interesting center reformations. The overall envelope of the storm continues W, and the overall circulation is pretty large. Aric makes a really good point that the centers may continue to rotate around a common point until they consolidate into a dominant center, so center reformations might not change the track as much as one might think. There is some chatter on another board that the large size of the storm may make it more susceptible to a poleward motion, since large storms help to erode ridges. Also, vapor imagery shows a ULL closing off over eastern Cuba, which could induce a more poleward motion if the ULL doesn't move. These conditions seem to favor the GFS solution. On the other hand, many models have shifted slightly left over the past 24 hours toward the Euro. The next Euro run will be very interesting indeed!!!

[Stephanie]

Isaac seems to have one side of the "eye" perpetually open as he gets himself into that classic buzz saw shape. Once it's all closed, watch out, IMHO. I looks dangerous already and the satellite radar makes him look like he's a fully developed hurricane even though the wind speeds aren't there yet.

[StormingB81]

Talk of multiple centers and wondering where between Texas and Florida it could go is reminding me of debby

[Emmett_Brown]

Isaac seems to have one side of the "eye" perpetually open as he gets himself into that classic buzz saw shape. Once it's all closed, watch out, IMHO. I looks dangerous already and the satellite radar makes him look like he's a fully developed hurricane even though the wind speeds aren't there yet.

Yep, when you back away from the screen a bit and look at the overall shape, he does look like a classic 'cane in the making. So, assuming he can work out his inner core issues, he certainly looks like he means business!

[artist]

From the P-3 flight twitter account (link posted earlier)
https://twitter.com/HRD_AOML_NOAA


HRD/AOML/NOAA ‏@HRD_AOML_NOAA
Report from #N42 in #Isaac: The circulation does not extend over a deep layer. There is strong easterly flow at 4-5 km altitude.

16m HRD/AOML/NOAA ‏@HRD_AOML_NOAA
Radar analysis from #N42 shows a complex structure for #Isaac -- multiple circulation centers in a broad overall circulation.

[wxman76]

New low pressure 1003.7 mb (extrapolated) this time at 14.733N 61.150W Seems to confirm multiple centers at nearly the same strength. Interesting