HAGATNA, Guam (AP) — A slow-moving storm that had Guam residents bracing for a typhoon has been downgraded to a tropical storm, but the National Weather Service says the erratic system could regain strength and develop into a typhoon later this weekend.

The weather service says Friday that Tropical Storm Chan-hom is weaker and tracking north-northeast at 8 mph with sustained winds of 50 mph, down from 105 mph.

Meteorologist Derek Williams of the NWS says the forecast calls for Chan-hom to develop into a typhoon, but the longer the system sits in open water and spins, the likelihood a typhoon in Northern Mariana Islands decreases. He says the next 24 hours are uncertain.

Guam is already seeing some showers, which are expected to intensify through Saturday and into Sunday.