Tropical Storm / Hurricane Isaac – Update #2
Tropical Storm Isaac has continued with its westward movement through the northern Caribbean Sea. Impact on the western part of Hispaniola seems imminent.
The latest advisory by the National Hurricane Center in Miami, Florida, places Tropical Storm Isaac about 145 miles to the south-southeast of Santo Domingo, Dominican Republic. The storm has shifted slightly to the north and is tracking now to the west-northwest at 18 mph. The storm’s maximum sustained winds are still only around 45 mph, keeping Isaac a relatively weak tropical storm.
The official forecast by the NHC has shifted Tropical Storm Isaac’s official path more to the west, putting it possibly in line with Mobile, Alabama and Biloxi, Mississippi. The storm may pass over the Florida Keys, but right now it looks like the Florida peninsula may not be affected by the storm. The Florida panhandle, on the other hand, is a different story.
With the winds still relatively low for a tropical storm, and without Isaac having a well-formed eye, it looks like Isaac will run out of time to reach hurricane-strength before making landfall on Haiti and then Cuba. The hurricane warnings issued earlier today have already been downgraded to tropical storm warnings.
There’s general consensus with the computer models that Tropical Storm Isaac will pass over western Haiti and then move along the northern coastline of Cuba as it heads to the northwest around an area of high pressure. Remember that with the storm’s counter-clockwise rotation, chances are likely that Tropical Storm Isaac will curve more into Cuba than predicted. Surface friction between the landmass and the storm’s winds can cause that effect to occur.
I just wonder how much of an impact the surface friction will have with the storm having such a relatively low wind speed. I would imagine that the difference in windspeed between land and water would have a greater impact to the storm’s path if the overall winds were faster, such as hurricane-strength. Would a storm with only 45 mph wind curve as much inland as a storm with 80 or 100 mph winds?
Naturally, the longer that Tropical Storm Isaac remains over Cuba, then the less likely that the storm will be able to re-organize itself and possibly become a hurricane before striking the U.S. coast. The next 24-36 hours should give us a better idea if Tropical Storm Isaac will be much of a threat by the time it reaches the Gulf of Mexico and points beyond.
A HURRICANE WATCH is in effect for the following location:
- Haiti
A TROPICAL STORM WARNING is in effect for the following locations:
- Dominican Republic
- Haiti
- southern Cuba
- the southeastern Bahamas
A TROPICAL STORM WATCH is in effect for the following locations:
- central Cuba
- islands in the central Bahamas