ATL: ISAAC - Post-Tropical - Discussion

[Dean4Storms]

Isaac's been on the verge of "it's just about to explode!" for the last 5 days, what's different today that would actually cause that to happen?

To be honest I don't see that happening, more like slowly steady intensification.
I saw the discussion at Tally this morning talking about the low precip values along the gulf coast. I think that last trough brought in enough dry air to keep Isaac in check a bit.

[Dean4Storms]

I think the intensity forecast between the GFS and the Euro is the culprit in the difference of a move northward near the mouth of the MS River or a turn back westward as GFS depicts. A deeper system will move into a smaller weakness.

[cycloneye]

@HRD_AOML_NOAA
#NOAA42 is heading into forming eye of #Isaac. Radar shows rainband has rotated to N of center and merging with major band NW of center.

[Cyclenall]

Isaac's been on the verge of "it's just about to explode!" for the last 5 days, what's different today that would actually cause that to happen?

Yeah I hate it when tropical cyclones do that and they have been doing that more frequently in the past few years. It looks like it is about to go off and then nothing. Isaac and Ernesto have been two offenders.

While I'm not enthused about the current situation, this thing would have been dead for sure had it took a long track over the spine of Cuba and more, if it was struggling that bad just when it went off the coast, on the coast and it we would be talking about nothing right now. Just have to keep this in mind and remember that when the cliche's of "It could have been worse" and "we got lucky" start being thrown around.

[KWT]

Isaac's been on the verge of "it's just about to explode!" for the last 5 days, what's different today that would actually cause that to happen?

Conditions have never been that good aloft really, its not been about to explode at any point. Yesterday was realistically the first chance that could have happened as it pulled away from Cuba but even then there was mid level shear. Thats forecasted to really decrease soon (and indeed already has to some extent) and the models are showing a really good set-up aloft from 00z tonight onwards. So slow strengthening upto then followed by a 24hrs burst of quicker strengthening seems pretty reasonable IMO.

[OzCycloneChaserTrav]

I don't think a 3/4 is out of the question to be honest, it all depends on this next 12hrs, if it can develop a core in that time, it'll have 24-36hrs in possibly very favourable conditions if the models are close to what they show and as we've seen that is ample time for a system to strengthen a fair amount, even if it doesn't bomb.

I could see a very low end chance at a 3, but I don't see it having quite the time or organization to make a Cat.4

Personally I do not think this will be a weak category 1 at landfall. At least a mid to strong category 1 anyway, which would still pack a massive punch wind wise. Let alone the surge....it's my forcast but I think we will see Isaac strengthen quickly in the next 24 hours, and be a mid category 2 upon landfall. As he begins to move more to the NW-N he will begin to get away from that upper level low that has been inducing dry air and vertical wind shear. In a day and a half, reaching category 2 status before landfall is quite a possible scenario, and going by modeling it's possible. Se Louisana landfall....

All you doomsayers out there please do not take this as a forcast.

[tailgater]

Pressure drops a little more uniform on the last two approaches and the tweets sound like a core could be forming.

[KWT]

@HRD_AOML_NOAA
#NOAA42 is heading into forming eye of #Isaac. Radar shows rainband has rotated to N of center and merging with major band NW of center.

Sounds very telling to me, its quite a slow process this time around to form a core but it sure looks like Issac is now giving it a good go.

[Dean4Storms]

Think I see the Eye here on AVN imagery....

http://www.ssd.noaa.gov/PS/TROP/floater ... -long.html

[HurrMark]

Don't want to be one of those people who say "there's an eye!" when it's just a break of convection but we might be seeing something...unless it's just dry air intrusion. But I think this is finally getting itself together. Question is how much it can get itself together given the lack of real estate.

[SNOW_JOKE]

RGB showing a possible eye
http://www.ssd.noaa.gov/PS/TROP/floater ... 0-lalo.jpg

[rockyman]

Eye forming here? http://www.ssec.wisc.edu/data/1min/inde ... eight=null

[Kory]

According to the hurricane hunters, he is perfectly aligned now.

[tailgater]

That would be something, an eye with winds of what 55mph?
He must have had a wake call at around 6:30 cst.

[KWT]

I'd like to see more images first to confirm that is a eye, but the recon reports of an eye forming is interesting, especially as its happening at the same time as we are seeing something on the images.

[candycane8686]

Hi I've been lurking on this board for two years, and I don't recall ever seeing a storm give the NHC the run around this bad since then. ( correct me if I'm wrong). When this was forecast to hit the panhandle I moved the date to move into my new house to avoid the rain, ( upstate sc )but now it's continues to go west... Thanks for staying on top of this guys! I enjoy reading your opinions!

[Dean4Storms]

If it is an eye it is tilted, could be a break we'll see.

[rockyman]

If that is the eye forming, it is east of the NHC track

[Cyclenall]

I see an eye as well on NRL imagery (10:40 UTC or 18 minutes ago) that does look legit, I doubt its dry air or a break in convection. It could be tilted.

Hi I've been lurking on this board for two years, and I don't recall ever seeing a storm give the NHC the run around this bad since then. ( correct me if I'm wrong).

Welcome to S2K. Yes, I agree this TC has given them a very hard time in the last week and is one of the worst in terms of intensity. Just look at the first advisory for Issac, 95 knots in 96 hours was forecast...now its 15 knots lower than that currently forecast many hours after that 7 day period.

[Dean4Storms]

Small increase in the last center pass and the forecast track to the east. Seems to be moving more NW than WNW.