Tropical Depression 9: News, Notes and Concerns
Nearly two weeks later and Tropical Depression Nine (TD 9) continues to march onward, despite the plethora of rumors and forecast a week ago that called for its demise as it tracked north of Hispaniola and Cuba. As of this evening, TD 9 is continuing to show signs of convection with new thunderstorms firing on the western and northern peripheries of the storm. It is looking quite healthy, and the healthiest it’s looked, yet.
Here is a look at the latest IR satellite observation of TD 9…
TRACK: I continue to remain skeptical of the forecast track for TD 9. This storm system will be battling to very important elements as it makes its approach into the Gulf of Mexico: an upper low in the western Gulf and a ridge in place across the Southeast US. How both of these interact with TD 9 will determine the path and curve it takes. I still feel that the upper low will try to pull it farther west than what model guidance is indicating before it begins a northerly track and curves into the Gulf, but only time will tell.
Here is the latest forecast track as issued bu the National Hurricane Center…
Because of my reasons for my skepticism of this track I mentioned above, I could see the forecast track shifting west a bit, might not be a significant adjustment (not into the western Gulf), but I would not be surprised to see a slight nudge west of its current placement. The longer it moves NW and N as compared to a NE heading, the longer it will take to make landfall.
Looking at model plots for TD 9, you might notice that from previous model plots, there has been a bit of a westward trend with model guidance. A number of model plots bring TD 9 more north as compared to a northeasterly track, something I do not think we can just discount right now. This is something that we need to continue to watch over the coming days. For now, I would say if you were to draw a line from the Florida/Alabama (just east of Mobile Bay, AL) to near Tampa, Florida, this would be where I would place the potential landfall area for TD 9, meaning folks in these areas need to be on alert and stay up to date with the latest on this storm system. While this area might not be a widespread area, it’s tough to pinpoint a location and say “that’s where this will make landfall”. We’re not at that level in this science yet.
INTENSITY: Most model guidance brings the intensity of TD 9, at its peak, to a tropical storm. A few members bring it up to a low-end hurricane. Will this wind up becoming a tropical storm or hurricane? Honestly, I don’t think we can discount any of those as possibilities at this point.
Look at shear tendency across the Gulf of Mexico, and there is little to no shear for the next 12-24 hours across the Gulf. Also we note that an upper level high is situated right over the circulation of TD 9 which is a very favorable environment for strengthening across the upper levels.
Coupled with little to no shear is incredibly warm waters across the Gulf of Mexico, with temperature readings in the mid to upper 80s. As I’ve said many times, warm waters coupled with minimal shear (or no shear) act as jet fuel to intensify a weak storm, and I suspect this will be the case for TD 9 moving forward.
WEEKEND CONCERN: Will this system curve out to the Atlantic or will it recurve up and into the east coast by the weekend? Model solutions have been hinting at this idea for several runs now and it is deserves attention. This solution is dependent on whether or not wind coming off a developing low will be able to pull the system back into the Northeast. How strong or weak the system will be at that time is still uncertain or whether it even recurves. Something we need to keep an eye on as well…
A lot of things to continue to watch for and a lot of information to digest. For those folks within the projected path of TD 9, be vigilant and stay up to date with the latest.