At 11am this morning, Tropical Storm Isaac’s intensity was increased to 60mph; still a tropical storm, but the strongest it’s been so far. It’s located south of the Dominican Republic and Haiti, and moving toward the west-northwest. The circulation is large, so locations hundreds of miles from the center are experiencing tropical storm conditions. Although, as of this post we are not under a watch, it’s very likely that a tropical storm watch will be issued for us later this evening.
The big two factors of interest to everyone here are wind and rain. The latest tropical storm force wind probabilities for the next five days are shown in this graphic. According to the official forecast from the National Hurricane Center, Miami has a 26% chance of experiencing tropical storm force winds (focused almost entirely between Sunday morning and Monday morning). It is not completely out of the question that we could experience hurricane conditions in that timeframe either… it will depend on how quickly the storm recovers after passing over Cuba. You will notice the weather turning for the worse on Sunday morning, so it would be best to do the bulk of your preparations on Saturday if it still looks like a threat.
And for rain, HPC has predicted about 7-8” of rain for us, but that’s still 2-3 days out, so the exact forecast will change as the storm gets closer and the track is better known. Even 3-4” is a lot of rain, however. I have several radar loops available that will cover Isaac’s path over the next few days to help track the center as well as the outer rainbands. Again, even if the center passes west of the Florida peninsula, we would still feel some effects here, including strong winds and flooding.
To summarize the local aspects, it currently looks like we can expect the rain and stronger winds to pick up on Sunday morning, getting worse throughout the day. Plan for very heavy rain from midday Sunday into midday Monday as well as tropical storm force winds, with a very slight possibility of winds nudging into Category 1 hurricane force range. Conditions should start improving and clearing later on Monday.
Brian McNoldy
Senior Research Associate
& Author of Tropical Atlantic Update
Follow Brian on Twitter: @BMcNoldy