Over the weekend, northern portions of the Leeward Islands, the Virgin Islands, and Puerto Rico are expected to receive tropical rain ranging from 2 to 4 inches, with isolated totals up to 6 inches. Flash flooding, landslides and mudslides will be the main concerns over the next several days.

Powerful Hurricane Erin has undergone a period of astonishingly rapid intensification — a phenomenon that has become far more common in recent years as the planet warms. It was a rare Category 5 for a time Saturday before becoming a Category 4, churning through the Atlantic Ocean north of the Caribbean.

Hurricane Erin formed in the Atlantic Aug. 15 and rapidly strengthened to a catastrophic Category 5 storm with 160 mph winds on Saturday, Aug. 16, according to the latest advisory from the National Hurricane Center.