Non-tropical system (#90L) in the Atlantic less likely to add to the 2023 hurricane-season list

The large non-tropical low-pressure system we have been following in the Central Atlantic is now officially labeled Invest #90L. This allows the National Hurricane Center to run additional analysis products on the system – that is, to “investigate” it. The result is that it now appears less likely the low will take on some tropical properties and potentially get named Vince.

The low-pressure center has separated from the fronts as forecast, but that’s only the first step. Organized thunderstorms have to wrap around the circulation for it to be considered to have tropical characteristics. If that were to happen, the system would first be designated a Subtropical Depression or possibly Subtropical Storm Vince if the winds were 40 mph or higher. Subtropical means it has properties of both a non-tropical and a tropical system.

The upper-level winds over the system are forecast to become increasingly hostile, and the atmosphere is on the dry side, which are both inhibiting factors for development. As a result of the latest analysis, the National Hurricane Center now has the odds as low that the system will take on tropical characteristics.

In any case, the low is heading toward the Azores – Portuguese islands in the northeast Atlantic. It will pass through the islands on the way to the cold North Atlantic late tomorrow and Sunday.

This is likely the last hurrah for hurricane season. Nothing else is in the pipeline before the official end next week.