In brief: As Gabrielle heads out to sea and toward the Azores, we’ll begin to pay close attention to two newly minted Invests, 93L and 94L in the southwest Atlantic. The whole pattern bears watching for the East Coast over the next week or so. But uncertainty is extremely high, with a lot happening over a small area and any one feature having impacts on the others. We explain the delicate ballet unfolding today.
Major Hurricane Gabrielle
We’ll be quick on this one. Gabrielle intensified into a category 4 storm with 140 mph winds. The storm has probably peaked in intensity now and is going to move eastward out to sea.

The next questions for Gabrielle are how it will impact the Azores and if it can make it to Europe. Gabrielle should remain a fairly formidable, albeit less intense storm as it moves near the Azores on Thursday or Friday. More details to come on that. It’s still a bit too soon to say how it will impact Europe, but it’s possible a remnant low approaches Portugal by early next week. In the near-term, interests in the Azores should be monitoring Gabrielle’s progress.
Atlantic Invests

The area in the Atlantic with higher development odds right now is Invest 93L. This trailing disturbance has a 90% chance of development. Invest 93L has a similar look and feel to Gabrielle right now, and the models are indeed latching onto a higher chance that this develops by Thursday. Invest 94L will be moving into the Caribbean over the next couple days, so it’s likely that land interaction will inhibit its development. By Thursday morning, we expect to see 93L northeast of the islands and probably on the way to becoming a tropical depression. Invest 94L should be in the Turks and Caicos Islands or near Hispaniola as a tropical wave/disturbance.

Up to this point, the forecast should be rather straightforward. Beyond this point?

There are about a million things that could happen after Thursday or Friday. The complicating factors right now include a.) What happens to 94L in the islands? That will help determine how far west it can get before being tugged north. b.) How strong does 93L get and how fast? That could help determine where it’s placed relative to 94L by the weekend which could influence both the track and development of 94L; they are fairly close together after all. c.) What about the trough in the Southeast? Will it be progressive enough to try to “capture” 94L and pull it into the Southeast or Mid-Atlantic? Or will it leave 94L stuck between a rock and a hard place with little opportunity to maneuver?

The bottom line in all this is that there is a *lot* of uncertainty in the pattern this weekend. Inject two possible tropical systems into the mess, with all these players residing over less than 1,500 miles of distance and you have a recipe for extreme uncertainty. As the Southeast trough exits, it could theoretically “capture” the disturbance and pull it more north or north-northwest toward the Southeast or Mid-Atlantic coastline by Sunday or Monday. Or later. And I think that’s where much of the concern sits right now in terms of land impact. It’s one of several possible outcomes. Folks on the East Coast from Florida through New England should monitor the progress of these systems in the next few days to see if we can pull a signal out of this. Because right now, we can’t.

Bottom line: No one has any idea what these are going to do, and all you can do at this point is monitor the forecast and make sure you check on your hurricane plans and kits on the East Coast.
In the very near-term, Invest 94L will bring heavy rain to Puerto Rico and the Virgin Islands today.
Localized flooding is a possibility in the heaviest rains. This will continue tomorrow and Thursday as well, easing up by Friday and Saturday.