Tropical Depression Grace is not going to head toward Florida. Just like Fred last week, it insists on tracking down the left side — the south side — of the cone. It looks like Grace will just skim the southern part of the Dominican Republic and Haiti, which means most of the circulation should stay over the warm Caribbean waters.
Even though the center of the system will likely be over the water, Grace is dragging along plenty of moisture to its north, which unfortunately will cause heavy rain over the mountains of both the DR and Haiti.
The National Hurricane Center is forecasting 4 to 8 inches of rain with some locations receiving up to 15 inches. Flash flooding and mudslides are possible. This coming on top of the earthquake catastrophe in Haiti is hard to imagine.
Evidently, the strength of the high-pressure system draped from Florida across the Atlantic has been consistently underestimated in the computer forecast models. The stronger the high, the greater tendency for tropical systems to be pushed south. There will have to be further analysis of the weather pattern and the model outputs to figure out why this is so consistently happening.
For the next two days, predicting exactly where Grace is going to go is still going to be tricky. First, the general rule applies that forecasts for weak or just developing systems have larger errors than for well-developed storms including strong hurricanes.
But second, as we saw with Fred, the wind flow around and over the tall mountains in the northern Caribbean can add a chaotic component. Perhaps now that it’s clear that much of the circulation will track over the Caribbean waters, the forecasts will settle down.
It now appears likely that Grace will track through the Caribbean and into the Gulf, although the Cancún area in Mexico might be affected by a strengthening storm.
The current thinking is that it will stay well south and west of Florida.
Tropical Storm Fred is on track to make landfall today in the Florida Panhandle, not far from Panama City. Winds in some locations at the coast could gust to hurricane force, which will obviously be disruptive. But Fred’s widespread impact will likely to be the rain.
Rainfall amounts approaching a foot are forecast in some areas from the Panhandle across the Southeast and north into the Appalachians.
Because of the persistent onshore wind in Big Bend of Florida, the Gulf water is forecast to be pushed 3 to 5 feet above normal high tide well to the east of where Fred’s center will make landfall. That part of the Gulf of Mexico south of Tallahassee is the most vulnerable area on the Gulf coast to high storm surge.
The weather in the Panhandle will deteriorate this morning with landfall near Panama City coming late this afternoon or this evening.
Tropical Depression Eight has formed near Bermuda. For the next few days, it will drift in a loop around the island. After that, some questions arise about what angle it will take as it moves away from the island, but it will be in the open ocean.
In any case, it will stay well to the north of Florida. The only land area expected to be immediately affected is Bermuda, which will likely see bands of heavy rain.
The system is forecast to reach tropical storm strength fairly soon. It will be named Henri — pronounced in the French way.
Elsewhere in the Atlantic, nothing obvious is in the works. Still more Saharan dust is forecast to stream over the eastern part of the ocean. Disturbances will move off Africa, but none of them appear poised to develop quickly.
We are entering the peak of hurricane season this week when we have the highest chance of having a named storm or hurricane. Stay informed and be ready.