The National Hurricane Center is tracking two low-pressure area systems in the Atlantic, including one a few hundred miles north-northeast of the Azores that is moving toward Portugal and northwestern Spain. Both disturbances remain at low odds for tropical or subtropical development, but the northeastern Atlantic system could still change character by Saturday or early Sunday.
The northeastern Atlantic disturbance has a 20% chance of development in the next 48 hours and a 20% chance over seven days. The second system, several hundred miles east-southeast of Bermuda, has a 10% chance in 48 hours and a 20% chance in seven days.
Portugal and northwestern Spain
The northeastern Atlantic low is attached to a front, which is why it is still treated as non-tropical even though it is close to a window for change. A front is the boundary between air masses, and in this case it is helping organize clouds and rain around the disturbance while also limiting how quickly the system can take on tropical traits.
The National Hurricane Center says that low could separate from the front Saturday or early Sunday and acquire subtropical or tropical characteristics. If it does not, the system can still bring unsettled weather as it moves east-southeast at 10 to 15 mph toward Portugal and northwestern Spain.
Bermuda-area disturbance
The second low-pressure area remains weakly organized over the central subtropical Atlantic. It is producing a concentrated region of showers and thunderstorms southeast of its center, but surface pressures remain relatively high, a sign that the low is not especially strong or well defined.
That system is expected to drift west-southwest through Sunday before turning northward early next week. Any tropical development would happen slowly, if it happens at all, and the National Hurricane Center’s seven-day outlook keeps it at 20%.
Atlantic watch through Sunday
People in Portugal and the United States are the clearest audience for this forecast. The Atlantic systems do not present an immediate tropical threat to the United States, but the European side of the forecast deserves close attention because the northeastern Atlantic low is already moving toward land and could evolve before it arrives.
The next shift to watch is whether the northeastern Atlantic disturbance breaks from its front and becomes subtropical or tropical before or during its approach to Portugal and northwestern Spain. If that happens, the forecast changes from a routine Atlantic low-pressure area to a system with a tighter core and a different development track; if it does not, the story stays with unsettled weather and gradual movement through Sunday.
