Tomas is nicely demonstrating the degree to which meteorological models depend on the context of experience. This season I’ve read most of the discussions and advisories for most of the Atlantic storms, and generally speaking, the forecasts change only a little from time to time once a storm is named, and the final realized path and strength changes match very closely with with was predicted. Occasionally a storm is more poorly behaved than that. But Tomas, which formed in a place no other storms formed this year and that has existed under rather unusual conditions is giving the Hurricane Prediction center a run for its money. Position estimates made last night were scrapped this morning and replaced with a much adjusted itinerary, and this morning’s strength estimates have been modified significantly this evening.

So, the following is very much subject to change, but..

The good news: Tomas will probably not achieve Category Three status, or even Category Two status before it hits land. It is predicted to remain a Category One storm. This is still a serious storm (see below!), however.

The bad news: Tomas is predicted to pretty much smack directly into Port-au-Prince. The exact track is of course not known yet, but the specific trajectory being put forth by the hurricane prediction center has the eye of Tomas passing just to the west of Haiti’s capital city, which is not on the southern coast but rather at the head of a west-side bay. Nonetheless, the storm is going to overrun the region recently hit by a major earthquake which I’m sure you remember.

Below (as promised above): The fact that the wind strength of Tomas is reduced is nice and all, but in a place like Haiti, a bigger problem may be the amount of rain that falls. I have no idea how much rain is going to fall with this storm. Probably less than the average Category One hurricane because it is physically smaller, but this does not mean that major flooding and landslides and so on can be ruled out.

Despite the fact that the current prediction is as stated above, this is still four days off, and still quite uncertain. In fact, there are no watches or warnings in effect yet. If you have any interest in the region, however, keep an eye on Tomas.

According to the current models, Tomas the Hurricane will stay around the Category One/Category Two boundary over the next four days as it moves to the west then north. The predictions are very uncertain at this point, but Wednesday night or Thursday morning, Tomas may be near western Haiti and prepared to bear down on the Port au Prince area as a Category Two (or strong?) hurricane. It may also slip between Haiti and Jamaica, affecting both with strong tropical storm force winds and proceed on to eastern Cuba. Tomas continues to confuse the forecasters a bit more than the average hurricane.

What I find especially intersesting is the as yet not noted by the weather service blob forming right behind Tomas. The big double red thing to the southwest of the hurricane in this picture:

Is that Virginie?