In our 2010 season outlook, we stated that a moderate to strong La Niña would likely result in storms developing through October and right through the month of November. So far in October, we’ve seen hurricanes Otto, Paula and Richard form. That’s one per week.. Currently, there’s a storm center located about 1500 miles east-northeast of the Caribbean with winds to tropical storm strength. The National Hurricane Center has identified the storm as “Invest 90L”. We’ve identified it as the Tropical Disturbance 66. It’s a storm center with 40 mph winds, so the NHC could name it at any time this week. But this isn’t the storm I’m concerned about. It’s our Disturbance 67 in the central Tropical Atlantic that could develop in the Caribbean next week.
As of Tuesday morning, Disturbance 67 was located about midway between the eastern Caribbean and the west coast of Africa between about 3N-10N latitude. It’s a strong tropical wave that has some mid-level rotation associated with it. Atmospheric conditions are not favorable for any development now, but the disturbance will be reaching the eastern Caribbean early next week where conditions may allow for some slow development. In fact, the American, European and Canadian computer models have been predicting this disturbance to develop in each model run over the past 2-3 days. With such model agreement on development, we do need to pay attention to this disturbance. Let’s take a look at what the models are forecasting.
The American Model has been consistent in forecasting a rather sharp East U.S. Coast trough and an associated cold front extending into the western Caribbean by next Wednesday/Thursday. South and southwesterly winds aloft ahead of the cold front would pick up any developing storm over the central Caribbean and carry it northward, possibly toward Jamaica or the Dominican Republic/Haiti. Such a track would not be too uncommon for early November. High pressure building over the Gulf of Mexico would prevent any movement in that direction. The European model has a different solution, however.
Though the European model develops a storm in the south-central Caribbean on Wednesday, similar to the American model, it indicates a much weaker trough and associated cold front off the East U.S. Coast next week. The combination of a weaker front and weaker storm system could leave the storm trapped in the southwest Caribbean for a while, embedded within relatively light steering currents. This solution, too, is fairly common in November. At least both models are in general agreement that any storm developing in the Caribbean next week will probably not become a threat to the Gulf of Mexico, probably being the key word there. If the European model prediction verifies, and the storm becomes stationary in the southwest Caribbean next week, then it’s not a 100% certainty that it couldn’t be steered toward the Yucatan Channel late next week. In that case, it could possibly become a threat to south Florida. Chances of that appear to be low, though.
So here we are with 17 named storms, 10 hurricanes and 5 major hurricanes as we near the last month of the 2010 hurricane season. Our June 1st forecast was for 18 named storms, 11 hurricanes and 5 major hurricanes. With one more Caribbean hurricane next week, we’d precisely hit our seasonal forecast, numbers-wise. But I’m not so sure there won’t be another storm or two during the month of November.