Tomas has continued to weaken and is currently a low end tropical storm. The National Hurricane Center (NHC) has consistently been forecasting it to re-intensify to a hurricane before moving in the general direction of Haiti. On the latest advisory, the NHC shows the center nearing the south coast of Haiti in around 4 days. The average track forecast error in 4 days (based on statistics over the past 5 years) is 225 miles. That means that the center could pass over eastern Cuba or closer to the Mona Passage. That is the uncertainty we have to live with this far out.
I hasten to add that even if the center of Tomas does not move directly over Haiti and even if it doesn’t become a hurricane, Haiti could still have a problem.
The figure above shows the track of Gordon in 1994. The center passed over eastern Cuba and Gordon’s maximum sustained winds at the time were only 45 mph. In spite of this, associated heavy rains and mud slides over Haiti resulted in 1122 deaths based on a post-storm report by the United Nations.
I used to have a lot of satellite pictures of major hurricanes displayed in my office while I was working at the NHC. But I also had the image of Tropical Storm Gordon on display as well to remind me that you don’t have to have a hurricane or even a strong tropical storm to cause a large loss of life – especially in Haiti.