Hurricane Nicole weakened into a tropical storm on Thursday shortly after making landfall on Florida's east coast after barreling ashore with a brew of heavy downpours and fierce winds, the National Weather Service said.

Nicole had threatened coastal areas still reeling from the last major storm six weeks ago.

A hurricane warning had been posted for a 240-mile coastal stretch that included the Kennedy Space Center at Cape Canaveral, where NASA's new moon rocket stood exposed to the elements and anchored to its launch pad to ride out the storm.

Nicole was downgraded from a Category 1 hurricane to a tropical storm as it moved inland from Florida's coastline on Thursday.

The storm, which officially came ashore at 3 a.m EST, was packing sustained winds of up to 75 mph (120 kph) as it made landfall along the east coast of Florida north of Miami, the National Hurricane Center said. Speeds later dropped to 70 mph.

The hurricane center had issued storm-surge advisories for much of Florida's Atlantic coast, warning that wind-driven waves would wash over beaches and rush inland to flood low-lying areas well beyond the shore.

Storm surges wreaked havoc along the state's Gulf Coast and its eastern seaboard when Hurricane Ian crashed ashore on Sept. 28 and plowed across the Florida Peninsula to the Atlantic, causing an estimated $60 billion in damage and killing more than 140 people.

Nicole had been expected to pack less punch at landfall than Ian, which struck Florida as a major Category 4 storm. Authorities warned, however, that Nicole still posed a formidable threat, especially to structures and coastal foundations weakened by Ian.

"Dozens upon dozens" of oceanside buildings in Volusia County, including high-rise condominiums, have been declared structurally unsafe since Ian, with some now "in imminent danger of collapsing" from further shoreline erosion, Sheriff Mike Chitwood said.