ATL: ISAAC - Post-Tropical - Discussion

[KBBOCA]

Also, when do the models with the Gulfstream's data come out? (in time other than UTC, please )

I have been seeing mods & mets (including NHC Twitter feed) saying that the Gulfstream data will show up in the 5 a.m. Eastern advisories and track. I understand that means that data will be fed into the 8 p.m. (00 z) models tonight, which I believe start becoming available 2 to 3 hours after they run.

Just an amateur...

[brunota2003]

Yes...the 00Z (8 pm EDT) GFS runs start coming out around 11:30 pm EDT, and the Euro is usually a couple hours after that.

[JamesCaneTracker]

Based on Long Range Radar from PR. I would say that northern Circulation is certainly becoming the center... Below is a image showing the latest Radar and the direction the storms are going...

This is just my unprofessional take on it... Please see the latest from the NHC or your local office of the National Weather Service for any life or Death decisions!

[sammy126]

wow, I must say after being on this site for a few days, you all are very good at analysing isaac.
Do you all keep track of how many times you are right and wrong with your forecasting?
"Great site"

[WeatherGuesser]

Speed up to 45 on the 8PM, so maybe it's starting to rev the engine?

[tolakram]

Saved radar loop

Remember this is looking way way up at the MLC at this distance.

[tolakram]

Compare the radar loop with this saved IR loop

[cycloneye]

Speed up to 45 on the 8PM, so maybe it's starting to rev the engine?

...ISAAC A LITTLE STRONGER AS IT CONTINUES MOVING
WEST-NORTHWESTWARD...


SUMMARY OF 800 PM AST...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...16.2N 67.8W
ABOUT 190 MI...305 KM SW OF SAN JUAN PUERTO RICO
ABOUT 210 MI...340 KM SE OF SANTO DOMINGO DOMINICAN REPUBLIC
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 16 MPH...26 KM/H
MINIMUM CENTRAL PRESSURE...1002 MB...29.59 INCHES

[Aric Dunn]

The northern vort on its present course would landfall on hispaniola tomorrow. so if that ends up bring the dominant one then expect the models to change reflecting a system that will likely emerge very weak.

[HurrMark]

I don't know if I'm looking at this wrong, but I see no evidence that the center is anywhere near 16.2/67.8. All data I can find shows it is still somewhere below 16...based on the latest Windsat, I would put the center at 16.5/68.5 (not official).

[Air Force Met]

Based on Long Range Radar from PR. I would say that northern Circulation is certainly becoming the center... Below is a image showing the latest Radar and the direction the storms are going...

This is just my unprofessional take on it... Please see the latest from the NHC or your local office of the National Weather Service for any life or Death decisions!

That's just a piece of vorticity rotating around the center. It would put a center around 16.7/68.2...which if you look at the satellite...shows nothing is there but a feeder band.

Also...remember you are not looking at the sfc. At that distance from the radar, you are looking between 17K and 30K feet. No where close to the sfc.

[KWT]

Well the winds seem to have strengthened, probably due to the strength of the convective bursts, still poorly organised with regards to the structure however.

AFM, I disagree there, the microwave passes recently have shown a strong circulation in that location (you can tell by the way the convection curves around the southern side), so there is something of note up there, its certainly stronger looking than any other circulation out there at the moment.

[SouthFLTropics]

The northern vort on its present course would landfall on hispaniola tomorrow. so if that ends up bring the dominant one then expect the models to change reflecting a system that will likely emerge very weak.

Another possibility if the northern vort is the dominant one would be it being disrupted and a new vort/center relocation/reformation taking place. I'll say it again...Until Isaac interacts with the islands all options are on the table. Once we know where it will set up shop after the islands then we can nail down the long term track and intensity.

SFT

[SeminoleWind]

The northern vort on its present course would landfall on hispaniola tomorrow. so if that ends up bring the dominant one then expect the models to change reflecting a system that will likely emerge very weak.

Wouldnt that make it a little sooner and how might that change the "official" track?, if at all?

[KWT]

To back up the idea of the center being up there, this is recons latest pass through:

235030 1628N 06803W 8410 01545 0030 +189 +180 273010 011 027 002 00

Wind shift was a touch north of there, strongly agrees with radar and microwave that this is where the strongest circulation is right now...

Not to say that this will be the dominant vortex, but it is the strongest right now.

[hurricanes1234]

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.

Isaac is now beginning to heal from its poor structure earlier on. This could mean at least some steady intensification, or it could be one of the fluctuations the system is going through, between 40 and 45 mph.

[Shuriken]

If this verifies, we're looking at a storm forecast to be a strong TS upon exiting Cuba given another two and a half days to strengthen in the GOM prior to a non-recurve landfall scenario.

...that raises the hairs on the back of my neck.

[Aric Dunn]

To back up the idea of the center being up there, this is recons latest pass through:

235030 1628N 06803W 8410 01545 0030 +189 +180 273010 011 027 002 00

Wind shift was a touch north of there, strongly agrees with radar and microwave that this is where the strongest circulation is right now...

Not to say that this will be the dominant vortex, but it is the strongest right now.

was jsut about to mention that. the wind field around the northern vort appears to more defined this evening. there is a bunch of missing minob sets that would help but appears to better now. the mid level may die out tonight.

[Air Force Met]

I don't know if I'm looking at this wrong, but I see no evidence that the center is anywhere near 16.2/67.8. All data I can find shows it is still somewhere below 16...based on the latest Windsat, I would put the center at 16.5/68.5 (not official).

I think that is one they are hanging on to for continuity. There are probably 2 centers...one which is north and one south...under the main MLC near 15/68. I would expect the northern one to eventually get sheared out later tonight as the tstms deepen around the lower latitude circulation.

[KWT]

I don't know if I'm looking at this wrong, but I see no evidence that the center is anywhere near 16.2/67.8. All data I can find shows it is still somewhere below 16...based on the latest Windsat, I would put the center at 16.5/68.5 (not official).

I think that is one they are hanging on to for continuity. There are probably 2 centers...one which is north and one south...under the main MLC near 15/68. I would expect the northern one to eventually get sheared out later tonight as the tstms deepen around the lower latitude circulation.

Its a tough one, I think the northern one is starting to get much more defined, the recon pass matched that microwave pass very nicely with regards to the wind direction and the curvature of that convection.

Then again the MLC has better convective support.

Tough call, no doubt that the models are latching onto the northern one still.