ATL: ISAAC - Post-Tropical - Discussion

[Portastorm]

OK, I see where folks are getting confused. The NHC headlines on their advisories say Isaac is moving west-northwest ... but the actual storm coordinates/data says 305 degrees which is technically "northwest."

So ... there you have it.

[otowntiger]

I could see the hurricane warning for the panhandle being lowered to tropical storm warning later...they are not in the forecast cone any longer and the forecast radius of hurricane force winds based on current forecast is 30 miles to the ne and se of the center. Panhandle will see t.s. conditions unless a major jump north happens.

Also note that part of sw LA in the cone has only a tropical storm watch in effect by comparison. I could see that becoming a ts warning later...

Wow! Looks like N.O. is firmly in the cross hairs. I just hope and pray this thing stays this side of a cat 1 or less. The unfortunate thing is Katrina did her damage there as a low end cat 2. I hope the levees are shored up and the pumps are in good working order.

[windnrain]

I don't remember the last time I've seen a storm with so much time over open water not get hurricane status.

[ATCcane]

"THE INITIAL MOTION ESTIMATE IS 305/12. NO SIGNIFICANT CHANGE WAS
MADE TO THE PREVIOUS FORECAST TRACK. THE LATEST 12Z UPPER-AIR DATA
INDICATE 20-40 METER HEIGHT RISES AT THE 500 MB AND 400 MB LEVELS
ACROSS THE SOUTHEASTERN AND SOUTH-CENTRAL U.S....WHICH SUGGESTS
THAT THE SUBTROPICAL RIDGE TO THE NORTH OF ISAAC HAS STRENGTHENED
SLIGHTLY".

This part of the disc is slightly interesting.....

[DukeDevil91]

Dvorak is best it's ever been in my opinion.

Granted.... Storm won't go passed 70 knots without a surface low covered by mid and upper level cold tops

[gboudx]

I could see the hurricane warning for the panhandle being lowered to tropical storm warning later...they are not in the forecast cone any longer and the forecast radius of hurricane force winds based on current forecast is 30 miles to the ne and se of the center. Panhandle will see t.s. conditions unless a major jump north happens.

Also note that part of sw LA in the cone has only a tropical storm watch in effect by comparison. I could see that becoming a ts warning later...

Wow! Looks like N.O. is firmly in the cross hairs. I just hope and pray this thing stays this side of a cat 1 or less. The unfortunate thing is Katrina did her damage there as a low end cat 2. I hope the levees are shored up and the pumps are in good working order.

But Katrina was pushing a Cat4/5 surge. Yeah, it's intensity decreased as it approached landfall, but the surge remained. Post-storm studies shows 20+' surge.

[StormGuy]

I could see the hurricane warning for the panhandle being lowered to tropical storm warning later...they are not in the forecast cone any longer and the forecast radius of hurricane force winds based on current forecast is 30 miles to the ne and se of the center. Panhandle will see t.s. conditions unless a major jump north happens.

Also note that part of sw LA in the cone has only a tropical storm watch in effect by comparison. I could see that becoming a ts warning later...

Wow! Looks like N.O. is firmly in the cross hairs. I just hope and pray this thing stays this side of a cat 1 or less. The unfortunate thing is Katrina did her damage there as a low end cat 2. I hope the levees are shored up and the pumps are in good working order.

Wasn't Katrina a CAT 3 at landfall?

[Sanibel]

Whatever the Nino inhibition was that screwed-up TD6 is still in place IMO...

[DukeDevil91]

I could see the hurricane warning for the panhandle being lowered to tropical storm warning later...they are not in the forecast cone any longer and the forecast radius of hurricane force winds based on current forecast is 30 miles to the ne and se of the center. Panhandle will see t.s. conditions unless a major jump north happens.

Also note that part of sw LA in the cone has only a tropical storm watch in effect by comparison. I could see that becoming a ts warning later...

Wow! Looks like N.O. is firmly in the cross hairs. I just hope and pray this thing stays this side of a cat 1 or less. The unfortunate thing is Katrina did her damage there as a low end cat 2. I hope the levees are shored up and the pumps are in good working order.

Wasn't Katrina a CAT 3 at landfall?

Yes... HOWEVER! Katrina carried a past as being a 175 mph cat 5 and carried the aforementioned storm surge. Issac could landfall at the same wind speed and not sniff the damage Katrina did.

[TeamPlayersBlue]

"THE INITIAL MOTION ESTIMATE IS 305/12. NO SIGNIFICANT CHANGE WAS
MADE TO THE PREVIOUS FORECAST TRACK. THE LATEST 12Z UPPER-AIR DATA
INDICATE 20-40 METER HEIGHT RISES AT THE 500 MB AND 400 MB LEVELS
ACROSS THE SOUTHEASTERN AND SOUTH-CENTRAL U.S....WHICH SUGGESTS
THAT THE SUBTROPICAL RIDGE TO THE NORTH OF ISAAC HAS STRENGTHENED
SLIGHTLY".

This part of the disc is slightly interesting.....

Thats extremely important. Le Sigh.

[HurrMark]

Whatever the Nino inhibition was that screwed-up TD6 is still in place IMO...

Florence?

[crimi481]

Kinda looks like Center (whole comma shape) stepping more North - and bulk of highest tps pishing more west
http://www.ssec.wisc.edu/data/geo/index ... thod=flash

[KWT]

Interesting to see how this is evolving, models still don't do much with this system till tonight, so thats really make or break for this system.

For now its struggling on its eastern side, we'll see how it fares as it heads deeper into the Gulf.

Things can change very fast in the tropics, so we need to keep our eyes wide open...

[jabman98]

This storm is doing my head in. Would appreciate any input on this issue. A close friend is flying out of Houston (IAH) on Thursday late afternoon to go visit his dad who isn't doing all that well. This trip has been planned for a couple of months. I know Isaac isn't supposed to come to Houston, but the models have been all over the place, have kept shifting west, and it's making his assessment about whether or not to consider changing his plans a challenge.

Any thoughts on whether or not Houston's IAH airport would be affected on Thursday afternoon?

[JPmia]

Boy.. I am sure glad the Florida folks didnt get hit to bad...it was only a few days ago this was going to smack them pretty hard up the spine or into Miami....Dodged another bullet...

Yes we did .. again, but it was a nice experience for a tropical weather enthusiast. Lots of palm branches down, few small trees toppled here and there, some power outages.. nothing major. I will say that I was surprised by the storm surge in the intercoastal .. it was all the way up to the top of seawalls yesterday afternoon. That is at least 4-5 feet. I am sure our luck will run out someday.

[rtd2]

I could see the hurricane warning for the panhandle being lowered to tropical storm warning later...they are not in the forecast cone any longer and the forecast radius of hurricane force winds based on current forecast is 30 miles to the ne and se of the center. Panhandle will see t.s. conditions unless a major jump north happens.

Also note that part of sw LA in the cone has only a tropical storm watch in effect by comparison. I could see that becoming a ts warning later...

Wow! Looks like N.O. is firmly in the cross hairs. I just hope and pray this thing stays this side of a cat 1 or less. The unfortunate thing is Katrina did her damage there as a low end cat 2. I hope the levees are shored up and the pumps are in good working order.

Wasn't Katrina a CAT 3 at landfall?

Depends on what u calling a cat 3...us locals get touchy ...YES it was officialy a cat 3 with 127mph at first in burus la, 120 second at Ms/la line with a 922mb pressure!!! and 25+foot surge... 2 outta 3 aint bad..

[KWT]

Sure does look like N.O is in the path of Issac right now, I'm not sure winds will be much lower than Katrina given they'll probably get the NE quadrant at the moment, so even if it is weaker in terms of winds, a strengthening system into landfall vs a weakening is going to transport more in the way of winds down to the surface and so the practical wind impacts probably won't be that much different if Issac comes in as a high end 1 as NHC seem to think.

As I said, this eveing and tonight is judgement time for Issac, either it'll pull itself together and deepen quite alot, or the models forecast of a stronger hurricane will be bust.

[otowntiger]

I could see the hurricane warning for the panhandle being lowered to tropical storm warning later...they are not in the forecast cone any longer and the forecast radius of hurricane force winds based on current forecast is 30 miles to the ne and se of the center. Panhandle will see t.s. conditions unless a major jump north happens.

Also note that part of sw LA in the cone has only a tropical storm watch in effect by comparison. I could see that becoming a ts warning later...

Wow! Looks like N.O. is firmly in the cross hairs. I just hope and pray this thing stays this side of a cat 1 or less. The unfortunate thing is Katrina did her damage there as a low end cat 2. I hope the levees are shored up and the pumps are in good working order.

Wasn't Katrina a CAT 3 at landfall?

Technically yes, but what most of metro N.O. got was low cat 2 winds from what I recall. And yes the big difference in Katrina and what Isaac could/may do does have to do with the fact that Katrina was indeed huge and had time to build up quite a surge with the 175mph winds she once had in the middel of the gulf. Even if Isaac does strengthen signifcantly from this point on unless he grows dramatically in size and undergoes R.I. he may not have the same effects relative to storm surge.

Disclaimer: This is just my amateur opinion, please don't depend on what I say as any kind of official prognostication.

[wxman57]

Good analysis by the Hurricane Research Division indicating Isaac's TS winds only out to 134nm now vs. NHC's 180nm on the last advisory. Small area of 60 mph wind:

[wxwatcher1999]

So the strengthing ridge would make it go more west?