TROPICAL STORM LAURA IS ORGANIZING BUT ON A LIKELY TRACK SOUTH OF FLORIDA WHILE MARCO HEADS FOR THE

Tropical Storm Laura has finally gathered itself into a reasonably organized system, but it did so in a position that its forecast track takes it over the tall mountains of the northern Caribbean islands over the next couple of days. This likely means that a relatively weak version of the system will be over or near Cuba when it makes it closest approach to South Florida on Monday.

In the western Caribbean, Tropical Storm Marco finally organized as well. It will track near Cancún and head into the Gulf ahead of Laura. Both systems are threats to the Texas and Louisiana coasts.

It is possible, but not likely that Laura and Marco could interact in the Gulf. Their timing appears to be offset by a couple of days, however, with Marco arriving in the northern Gulf Monday but Laura not arriving until Wednesday.

In any case, they would not merge if they came close, assuming they both had well-developed circulations. They would deflect each other, and the stronger storm in this kind of interaction often weakens the weaker system.

TROPICAL STORM LAURA

Laura will track south of Puerto Rico today, spreading heavy rain and strong gusty winds over the island. Mudslides and flooding are the threat.

Given Laura’s increased organization, some strengthening is possible today before it reaches the Dominican Republic this evening. The current track shows Laura’s circulation center moving near or over the tall mountains of the Dominican Republic. These mountains have shredded stronger storms than Laura in the past. So it’s not clear what type of system will emerge near the eastern end of Cuba tomorrow.

The National Hurricane Center’s forecast takes into account the possibility that the circulation might skirt around the mountains or eke by over the water with only partial damage, and we have to be aware of that possibility. If a viable circulation gets deflected out over the ocean, Laura could come back quickly into a stronger storm.

The atmospheric environment over our South Florida and the Bahamas appears conducive for a stronger storm to develop, but only if it is not significantly dismembered over the Caribbean mountains and the center tracks over the water. This scenario doesn’t appear likely, but is not impossible.

On Monday, whatever shape Laura is in, it is expected to track well south of South Florida and the Keys. The strongest winds with the system are expected to extend north of the system 100 to 150 miles at that time, so areas in the Southern and Central Bahamas as well as the Keys and South Florida can still expect gusty squalls at the least with easterly and southeasterly winds.

The odds currently favor only a glancing blow on the peninsula and the Keys, but if Laura wobbles to the north and tracks over the ocean north of Cuba, there would be time for a stronger system in the vicinity of South Florida on Monday. Everybody needs to stay aware.

Once Tropical Storm Laura reaches the Gulf of Mexico late Monday, the storm is expected to organize and strengthen. The current thinking is that it will track toward the Texas, Louisiana, or Mississippi coast. The computer forecast models have been moving around with their prediction for what part of the coast will be most affected.

The disorganization of the circulation and the track farther south have changed the timing, so the weather systems that will affect Laura’s position as it moves farther north end up in different positions as well. Thus the changing forecast.

It appears Laura will have time to intensify into a hurricane in the Gulf, even if its circulation is significantly disrupted by its trek through the Caribbean.

TROPICAL STORM MARCO

Marco will precede Laura into the Gulf by a couple of days. The nose of the high-pressure area that is pushing Laura west will push Marco to the north. The atmospheric environment doesn’t look as conducive for strengthening in the northwestern Gulf for Marco as for Laura, however. Hostile upper winds are forecast over the area.

As a result, the National Hurricane Center is forecasting weakening near landfall on the Texas or Louisiana coast, but a change in the timing of the storm’s arrival could change the environment.

Needless to say, everybody along those coastlines should have their hurricane plans in place. They may well be impacted by two significant storms in two days.

EAST ATLANTIC DISTURBANCE

The disturbance that we have been tracking in the far eastern Atlantic has not developed and is not expected to. It will precede west as a moisture surge.