Nate taking Option #2 into Mexico; Watching Maria; More trouble down the road

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

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Tropical Storm Nate put on a little show yesterday, a rather surprising one, and got down to 995mb with 70mph winds, almost technically a hurricane, although he looked nothing like one. Dvorak satellite estimates were still at 35kts at the time, a weak tropical storm. This intensification was likely in part due to the curvature of the coast of the Bay of Campeche, which likes to help wind up small systems. However, Nate has been full of dry air for a couple of days now, and thus he got capped yesterday and has weakened some overnight, now likely a moderate tropical storm with very weak thunderstorm activity. He may also be cooling the water beneath him due to the fact that the warm water is very shallow in the southern BOC, and thus he is probably negatively impacting himself by remaining stationary in the same area for so long.

The models are now very bunched up on a WSW track into Mexico, and at some point when the models agree enough they are 99% of the time going to be correct about the overall motion. Thus, Nate is likely to take the option #2 that was mentioned yesterday as being the 2nd most likely track outside of a move towards Louisiana. This is obviously a bad forecast, but at least I was correct that the middle option, with a track towards northern Mexico/southern Texas, was ridiculous and was highly unlikely, and the track would be either north or WSW. The NHC was forecasting this 3rd option yesterday, and it didn't turn out so well for them, as their forecast has shifted 300-400 miles from yesterday. This was a difficult storm to forecast, but it's one we can learn from. I show in the video why I was wrong on Nate's path, so I can avoid that mistake next time.

This southern track makes Nate more likely to be a potent storm moving into Mexico, and I could see him trying to approach Cat 1 status once he moves over warmer water farther west if he can overcome the dry air around him, as he is fairly symmetrical, but Cat 1 will still be hard to attain, and I don't think he will reach Cat 2 like the 5am NHC forecast (edit: 11am forecast stays Cat 1). However, Mexican residents should closely monitor this system, as small storms can wind up in a hurry in the BOC, as we have seen many times before.

Tropical Storm Maria I think I will end up being correct on, unlike Nate. She looks "better" this morning in that she has a large area of intense thunderstorm activity, but her circulation is elongated and ill-defined based on recon data. She will likely keep moving WNW towards the general area of Puerto Rico and the Virgin Islands, and should be a solid moderate tropical storm in that area. Based on her appearance this morning alone, I would think that folks there in the Antilles should be expecting nasty weather for the next couple of days. Thereafter, Maria should continue northwestward and end up just northeast of the Bahamas in a few days. She will probably try to become a hurricane in this area, but may get knocked down later if she moves over the cold water wake left by Hurricane Katia. The models are mostly in agreement on my idea that Maria should recurve east of the United States, despite getting fairly close to the Bahamas. Again, the main reasoning for this is that a big Canadian trough has to come rescue ex-Lee's cut-off upper low over the central U.S., and as a result, a big upper trough will be in place to turn Maria out next week.

Looking ahead....I am still voicing concern over the period of September 15th to September 25th for the Caribbean, southern gulf, and Bahamas areas. With the southern U.S. cooling off, and the southwest Atlantic cooling off due to hurricanes, activity should get focused in the Caribbean as air is forced to rise, and we should get a storm there around the 3rd week of this month. Some ensembles are starting to hint at low pressure in the western Caribbean in 10 days, so we will be watching for more models to start latching on to this idea.
We shall see what happens!

NHC Official Forecast for Tropical Storm Nate:



NHC Official Forecast for Tropical Storm Maria:



Tropical Storm Nate Model Track Forecasts:



Tropical Storm Maria Model Track Forecasts:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity Potential (green areas represent upward motion associated with the MJO):