Flood alerts rise for 33 million as September nor’easter approaches

Flood alerts have doubled in the past 24 hours, putting 33 million people on the East Coast at risk as a rare September nor’easter moves toward the region, while a rapidly intensifying Hurricane Nolo threatens Hawaii. The National Weather Service issued a nationwide flood‑risk advisory on Tuesday, and the storm is expected to bring heavy rain, strong gusts and coastal flooding from North Carolina to New England later this week.

The nor’easter is unusual for September because the jet stream normally retreats northward, leaving the Atlantic coast with milder weather. However, a lingering trough over the eastern United States has pulled cold air down from Canada, setting the stage for a classic “bomb” cyclone. Recent weeks of above‑average rainfall have left many river basins already swollen, and soil moisture is near saturation in the Mid‑Atlantic. Climate scientists say a warmer atmosphere holds more water vapor, increasing the chance that any storm will produce extreme precipitation. At the same time, Hurricane Nolo, which formed in the central Pacific on Monday, has surged to a Category 3 storm with sustained winds of 115 mph, and forecasters expect it to approach the Hawaiian Islands within 48 hours.

Officials in several states have activated emergency operations centers and urged residents to review evacuation routes. The Federal Emergency Management Agency has pre‑positioned sandbags and portable generators in vulnerable coastal towns. In New York, the governor declared a state of emergency for five counties, and the New York City Department of Environmental Protection warned that the combined effect of the nor’easter and already high tide could overwhelm drainage systems. In Hawaii, the governor ordered all public schools to close on Thursday and urged tourists to stay in sheltered accommodations as Nolo intensifies.

The next 72 hours will determine the scale of the disaster. Meteorologists expect the nor’easter to deliver 4‑6 inches of rain along the coast, with localized totals exceeding 10 inches in the Appalachians, and storm‑surge heights of 3‑5 feet in low‑lying areas. Residents are advised to monitor local alerts, secure property, and be ready to move if orders are issued. The twin threats underscore the growing challenge of responding to back‑to‑back extreme weather events in a warming climate.