Weather Nerd

Gustav: the real deal?

After strengthening rapidly earlier today, Tropical Storm Gustav became a bit ragged on satellite this afternoon, and did not intensify further this afternoon or evening. Now, however, the storm seems to be getting a bit better organized again, and it may well become a hurricane overnight. Another reconnaissance flight is scheduled for around 2:00 AM EDT.

Although the forecast and the computer models call for Gustav to move northwestward, at present it appears to be moving due west. If that keeps up, it would increase the likelihood of the storm staying over open water, intensifying, and threatening Jamaica — and perhaps eventually the Gulf of Mexico — in a very serious way.

Over on Alan Sullivan’s blog, both Sullivan and commenter Steve Sadlov — who have been harshly critical of the “hype” surrounding recent storms — sound very worried about Gustav. Sullivan thinks Gustav will become “a major hurricane, and a serious threat in the Gulf of Mexico.” Even before that, he thinks a prayer for Jamaica may be in order. “This could be a really bad deal,” Sadlov wrote in comments there. He echoed that sentiment here: “This is the real deal.”

Here’s what Sullivan had to say in his most recent post:

NHC has been wrong about this storm today. They did not foresee its swift development, which I spotted first thing this morning, and they missed the error in the initial models — which presumed a storm moving NW. Gustav was actually headed WNW. This evening it has turned almost due W. On its current track, Gustav would make a direct hit on Jamaica, rather than passing between that island and the SW tip of Haiti, as I presumed earlier. Some models have suggested the storm could even slip south of Jamaica, the way Dean did last year. Looking at the cloud and vapor movements over a large region, I can see some basis for this scenario.

The NW Caribbean has higher heat content than any other part of the Atlantic Basin. Driven west by the trade winds, water piles up there before passing through Yucatan Channel. Hemmed by land, the warm surface layer becomes unusually thick. Thanks to this topographically-determined quality, the NW Caribbean tends to turn any passing hurricane into a monster, unless upper winds shear and weaken it. There is no sign of any adverse flow for Gustav on a course through that region. Expect a cat 4 or 5 cyclone to be making headlines in a few days, if Gustav’s core stays over open water south of Cuba.

That’s a bold prediction, but one that seems fairly plausible under the circumstances. Gustav could be the season’s first real “blockbuster” storm. Way too early to tell where it will go, but definitely keep an eye on this one. I’ll do my best to keep you updated.

Meanwhile, we could soon see T.D. #8, and maybe #9, soon. FWIW, the next two names are Hanna and Ike. But Gustav is likely to be the story in the tropics for the next week or so.