This is going to be one of those times when nothing comes easy. If we are going to have hurricanes, might as well have them easy to forecast and sometimes, even when they are intense like Katrina, they are. Others, not so much. The case with Joaquin looks to be a real pain in the neck. Before getting to the forecast part, let’s take a look at what we know.
As of this morning, Joaquin was a 40 mph tropical storm battling relentless northerly shear. Remember, upper level winds are not favorable when the pass over a developing or established tropical cyclone. The best environment is one that features outflow channels and light winds at the upper levels, to allow very deep thunderstorms to tower high in to the atmosphere. Right now, this is not what is happening with Joaquin and unless the shear abates, the storm will struggle.
Water temps along the track of the storm are plenty warm with ample undisturbed upper ocean heat content. While it is not nearly as high-octane as the NW Caribbean, the western Atlantic has plenty of energy for a hurricane to develop from and feed off of. The question is, will Joaquin thrive or starve at the head of the buffet?
It really will come down to how much the shear relaxes, if at all, in the coming days. Some of the intensity models show significant strengthening, as does the global model ECMWF. Keep in mind, some models are developed specifically for tropical cyclones where as the global models predict weather on a global scale and the tropical cyclone is part of the overall big picture. Right now, the NHC is admittedly being conservative with the intensity forecast – holding below hurricane strength.
Now for the track forecast. This is obviously what everyone wants to know about. As I said in my opening paragraph, we wish it was always easy but it’s not and so we deal with it.
I want to point out that the NHC makes mention of the fact that their confidence in the track forecast is “extremely low” right now. I think this is incredibly honest and shows the human side of this tedious work. Model guidance is helpful but is spread out right now, or divergent, and thus the forecast of where Joaquin will track is very tough to call. Here’s why.
First, intensity will likely dictate track to some extent. A stronger, deeper hurricane situated in the atmosphere might, just might, be enough to get swept out to sea by an approaching trough of low pressure moving in to the Southeast later this week. On the other hand, no matter what the intensity of Joaquin is, it may get caught by the trough if it tries to cut itself off from the main flow- what we call a cutoff low. This could swing Joaquin northwest with time and bring it in to the Mid-Atlantic states later this weekend. Many of the model solutions show this happening to some extent. Of course, others do not. This is why the track forecast is so tough to call right now. What’s more frustrating is that we are not talking about a week to 10 days out like we see with large hurricanes coming in from the eastern Atlantic. Joaquin is literally in the backyard, waiting to make its move. You would think, and hope, that with it being so close to land already (relatively speaking of course) that the forecast would be easier. It’s just not and that’s the reality of the situation.
One thing we can count on is data. NOAA will have plenty of additional data to input in to the global models as soon as the G-IV missions begin for Joaquin. The high-altitude jet will drop numerous devices that will sample the atmosphere and give the models more data from the steering layer to work with. This should help to refine things in the days to come.
So what should you be doing now if you live along the coast from say, North Carolina to Maine? Just keep monitoring what’s going on and be ready to act if it looks like Joaquin will in fact head your way. Remember, even if it transitions from a hurricane ( assuming it becomes one) to a post-tropical storm or other less commonly used term, there will likely be a lot of rain, wind and more coastal issues. The beaches from parts of eastern Florida up the East Coast are not in their best shape right now due to recent nuisance storms and persistent onshore flow. Joaquin need not be a substantial hurricane to cause substantial problems for people and property. Do not lose sight of the fact that a storm of any magnitude can impact you. Needless to say, it will be a very interesting next few days.
As if Joaquin weren’t enough, we have to watch for the remnant energy from Ida to try and stage a comeback. The NHC gives it a 40% chance of doing so and there is a chance that this system too gets involved with the pattern near the East Coast in the coming days. The result is likely to be a tremendous amount of rain and serious beach erosion from the North Carolina Outer Banks to New England.
I will post a full-featured video update this afternoon highlighting the very latest on Joaquin and what the chances are of Ida making a comeback. Stay tuned, it looks like October is going to start off very stormy – how much so and what impact it all has remains to be seen.
M. Sudduth 8:40 AM ET Sept 29