• Bryan Norcross


The center of Hurricane Sally arrived late and in the wrong place, but it has finally made landfall very near the Alabama/Florida border between Mobile and Pensacola. The estimated peak winds in the circulation at landfall were 105 mph.

This has been a very humbling storm for forecasters and, no doubt, a frightening and harrowing night and morning in the Mobile and Pensacola area.

Every time is looked like Sally was weakening, it put on a burst of strength. It did that last night just before landfall, ending up a strong Category 2.

Making it worse, the slow forward motion of the storm pushed the Gulf water higher over the coast of Alabama and the western Florida Panhandle. On top of that water, the rain will continue to fall in record amounts as the storm creeps north.

I don’t recall a storm in recent time that has so drastically shifted its track in such an impactful way in the short period of time before landfall. The change has been about 100 miles in the past two days, from the west end of the Mississippi coast to the Alabama/Florida line. But for people living in coastal communities, it’s been drastic.

Areas that were not threatened with the worst of the storm, suddenly were. By the time the danger was apparent, in some cases escape routes were flooded. In addition, it's very hard to get people who weren't worried to take sudden action.

We don’t know yet what actually happened on the ground in those coastal communities.

Many aspects of hurricane forecasting have tremendously improved over the last 10 or 20 years. But predicting exactly what’s going to happen with a slow-moving, developing storm is still impossible. The factors that make a difference are subtle because there is no strong flow that dominates in the atmosphere.

When Sally suddenly intensified on Monday, the center reformed with the net effect of slowing the system’s forward speed to essentially zero. That process is unforecastable, even though it made a significant difference in who got the highest surge and the heaviest rain.

That original delay started a whole cascade of forecasting challenges that continued right up until landfall.

The National Weather Service is still forecasting a total of 10 to 20 inches of rain in the area near and to the right of the landfall point, with some spots getting 35 inches. The rain will not be able to run off because of the storm surge elevating the water in the bays and waterways, so major flooding will continue for some time. The threat will move inland as Sally moves north.

Elsewhere in the tropics, persistent Disturbance #1 is still threatening to organize in the southwestern Gulf. The long-range computer forecast models show slow organization over the next several days. It might mix with a coming cold front next week. We’ll keep an eye on it.

In the Atlantic, Hurricane Teddy has formed. It is forecast to turn into a large powerful hurricane over the next 5 days as it tracks in the general direction of Bermuda.

People on Bermuda are watching warily. They were just run over by Hurricane Paulette last Monday. There was some damage and power was knocked out to about three-quarters of the island, but they are bouncing back quickly.

Now, Paulette is heading off into the North Atlantic, but the system or its non-tropical remnants are forecast to loop back south. As it comes south, it could become tropical again. But even with all this running around the ocean, it should stay away from land.

Tropical Storm Vicky is forecast to last another day or so. It’s expected to slowly wind down without affecting anybody.

Disturbance #2 is looking a little bit better organized. There is a good chance that it will develop into our next tropical depression or tropical storm.

It’s moving slowly toward the west – in the general direction of the Caribbean islands. It may not make it that far, however. The atmosphere ahead doesn’t look supportive for much development, in large part because Hurricane Teddy will be trailing a strong channel of wind in the upper atmosphere in its wake. In any case, it’s not a threat to land through the weekend.

If Disturbance #2 gets named, it will be Wilfred – the last name on the 2020 list. The following tropical system that reaches the 40-mph threshold will be named Tropical Storm Alpha.

Disturbance #3 is a large, currently non-tropical low. It’s moving south toward warmer water. Sometimes a tropical system can form out of these non-tropical circulations. It’s not expected to threaten land.

The long-range computer models continue to show the season’s first cold front pushing south into Florida next week. It will be noticeable in South Florida by the strong breeze coming off the ocean. We’ll watch the tail end of front, and all of the fronts this fall, when they get into the Gulf of Mexico. Sometimes they are the seeds for tropical systems.

For now, no tropical development affecting peninsula Florida is expected into early next week, at least.

© 2019 by Bryan Norcross Corporation



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