Tropical Storm Leslie- What happened to regaining to Hurricane strength?

That right there is the question that we want to address first thing in this over night discussion. If you recall from past discussions we talked about that Hurricane Leslie would be weakening.. and right on time that indeed did happen and ended up being the case.. Just as of 15 hrs ago approximately NHC issued this as there 11 AM advisory...

LESLIE WEAKENS TO A TROPICAL STORM BUT FORECAST TO REGAIN HURRICANE STRENGTH...
11:00 AM AST Fri Sep 7
Location: 26.8°N 62.2°W
Moving: Stationary
Min pressure: 981 mb
Max sustained: 70 mph

Well folks , it does not take a rocket scientist to discover that this has NOT happened.. We have not regained hurricane strength... and as of 2 AM.. we find this...

LESLIE MOVING SLOWLY NORTHWARD...

2:00 AM AST Sat Sep 8 Location: 27.8°N 62.3°W Moving: N at 3 mph Min pressure: 983 mb Max sustained: 65 mph

Matter of fact instead of strengthening it had weakened further and again this was something that was NOT anticipated on the National hurricane Centers part.

Well the problem comes in two fold .. 
1. Models are not coupled with the ocean , at least not global models..So what this means is that because Leslie is essentially stationary to barely moving for quite some time it has upwelled cooler waters. We mentioned this past couple updates and this is something that models do not take in to account when we look at the intensity they are showing..
2. We mentioned the size of the system and the fact that it was not and still is not vertically stacked would mean that this system would have trouble developing. 
3. We have also pointed out the dry air that has been effecting this system.
4. We have also pointed out that shear was still a problem and as you will see continues to be a problem ..
5. Leslie is caught in week steering currents...

The intensity forecasts on this system have been pretty bad ..this simply says to me that the science is not yet at the point where it can accurately forecast intensity of Tropical Cyclones and more study has to be conducted into this. 
So lets look at what is presently happening with Leslie now... we feel that the current environment is a lot more important piece of the forecasting tool then the actual guidance...

Very first thing we are going to look at is the visible and the water vapor images. The wide view just shows you how large this system  is and remember the larger a system is the more difficult and longer time it takes for the center to contract and the system to intensify.

The next thing we need to notice is all the brown color on the bottom image on the left side of the image and to the south of the image. What this tells us is that dry air is still being entrained into the center of the circulation and the visible shows this process very well..

The next thing we are going to look at is that the 700, 500 and 200 mb vorticities are still not vertically stacked...

Diving even more into the atmosphere is looking at the shear..and the models were actually forecasting for shear to DECREASE... Instead let us see what we have occurring..

This shows that over the northern part of Leslie that the shear is anywhere from 10 -30 knots. Again.. ideal shear environment for strengthening is 5-10 knots..Anything above will cause the system to develop a lot more slowly if not curtail development. Factor in the dry air and you can see why this has not strengthened but only been weakening and maintaining.. But lets look at the shear tendency map to get the total picture..

Remember we are moving slowly , barely north and to the north and west and east and south there is nothing but increasing shear...

The only thing that continues to pretty much lay in favor with this system is the convergence and divergence continues to be decent across the system..

Now you can see where ADT puts the center location and this system has barely moved thru out the course of the day.. You can especially see this if you check out the loop in motion..

So as you can see the environment continues to not be to friendly for further strengthening and this may have trouble strengthening while it is over colder waters from up welling. Once it starts to actually move north it could potentially develop further but with the increasing shear that may end up once again hindering the development..

00Z Guidance essentially is all now in agreement on a track just east of Nova Scotia. However, there are some timing issues still involved..

So in summary the atmosphere or environment around Leslie is really not conducive to strengthening at this point and time. The movement will continue to be very sluggish and slow and may meander north and south etc over the next day or two because of the mid level ridging that is to its north. Then .. at some point the trough will be coming off the east coast and this should start Leslie to begin taking a more NE track.
By the time this system gets to the Nova Scotia and New Foundland regions this should be an extratropical cylone. IF the SHEAR does not let up as forecasted there is the potential that any strengthening could be further delayed and we do not make it back to hurricane status...So this is something we will have to watch.
No change in track forecast that was issued and next outlook will be in 24 hrs from now!
Have a great night!