Isaac Disrupted By Haiti-Models Shift West

At the present point and time we are not going to change our track. The track that we laid out about 24 hours ago shows basically landfall around the MS/AL border however the cone of uncertainty stretched east to the Western panhandle of Florida and West to New Orleans.. This seems to be the case as of tonights model guidance with one noticeable exception -the model guidance that is going into the Western Florida Panhandle is shrinking...

Matter of fact there has been a lot of talk about the current movement of the system. NHC has the most recent direction as NW and this is what the 6 Z guidance (early ) shows as well and with that being the case lets just see where this would end up IF it were to continue to move on its projected heading. Follow the orange line labled Xtrap

Now as you can see by the orange line on the current heading it would be going right across New Orleans region. Now this is remotely interesting because MAJORITY of the guidance has shifted to the West tonight and puts New Orleans into the target zone .. So lets look at the guidance from 00z and the early 6 Z guidance..

First the GFS ..

So much for the eastern track on the east side of florida or for that matter the central track up the middle of the state of Florida. Although in reality aside from one or two runs of the GFS this option was never on the table and if you followed us here you were well aware of the reason why which was the strong ridging to the north and the steering currents in place.
GFS ensembles have also trended west and also take aim at the New Orleans area..

So you can pretty much see that the means back up the operational model. Next up is the 00z GGEM. Now with this image you simply have to look for the red line which represents the 00z run ..

As you can see the GGEM is also taking this on a pathway towards the New Orleans region. So this is now two models from the 00z run that favor a significantly further west track..

Next model above is the 00z Nogaps and if you read the facebook page earlier in the day when we posted the 12 Z we said that this was west of the ECM for example and that usually that indicates a red flag..meaning the ECM was to far east and should come back. It is important to remember when it comes to the ECM ..it is the better verifying model but its best statistics are not until hrs 48 as when it becomes deadly and can not be beat..

So with that said lets look at the ECM which this is approximately 72 hours away yet from impacting the USA.

Should not really be a surprise that the ECM has come back west from its 12 Z run with just about every other piece of guidance we looked at doing the same thing. This is not as far west as the GFS/NOGAPS/GGEM  and as you will see the HWRF but it is a trend in those model camp directions..

No explanation is needed for the above images this would be a very powerful and significant Hurricane targeting guess where? If you said New Orleans you would be correct...

The only other model that did not come West and is still in the Florida Panhandle is the UKMET..

Now lets move on to the 6 Z early guidance model runs. These would be the dynamical models..

As you can see the majority of these are west and they are towards New Orleans. Some are further east across the Panhandle area and some around the MS/AL border. Only one curves to the NE . 

So as you can see there is an ABUNDANCE of EVIDENCE from the guidance that this SHOULD be shifting further west.. And one of the reasons is that right now the system is very disorganized and got disrupted from Haiti and it has to essentially reorganize its inner core and become vertically stacked again. This makes it more subjected to the steering currents once again which show a west to Northwest trajectory .

We continue to think that Isaac is going to have some trouble re organizing its structure over the next 12 -24 hrs . Part and partial due to an Upper Level Low that is sitting at 22 N and 78 W and you can see this on the water vapor..

It is this same upper level low that the models start to move out of the area which SHOULD enhance the outflow and then that occurring and in combination with the shear dropping (though there is still some increasing shear around it) the shear that is dropping is in the GOM region...and the warmer waters should allow this to start increasing in strength once the center is west of Southern Florida..

The above image on top shows the current shear and the below shows where it is dropping and where it is rising and you can see to its N and to its W as well as its east there is increasing shear but once you go beyond that and you get into the GOM it is decreasing.

Convergence and Divergence is actually decent across the system which will be another factor in aiding Isaac to re strengthen but not in our opinion for another 12-24 hrs . 

We still feel quite comfortable with a landfall around the Ms/AL border and we also feel fairly confident that once this gets over the GOM waters that significant increase in strength is likely and that a CAT 3 is not out of the question. 
However if the guidance continues to shift west the track will have to shift west and that would then but the landfall very close to New Orleans!

No matter where this makes landfall its going to be a powerful storm with Heavy rains , High Surf, Flooding, Beach Erosion and extremely gusty winds . 

Just as a side note NHC as of 5 AM has shifted their track west with now New Orleans in the cone and landfall around the MS/AL border... This is very similar to what we posted last night..

We want to make it clear that synoptics said from the get go that this was never going to be an up the east coast threat or a eastern Florida hit. We been on top of this since day one of tracking it and as always we will continue to provide you with the most accurate forecasting possible. We will update this in 24 hrs once again.