Tropical Storm Helene quickly weakened into a tropical depression Saturday after moving ashore on Mexico's Gulf Coast, bringing strong rains but few reports of damage.

Forecasters said Helene still posed a threat to areas where thousands of people are recovering from flooding spawned last week by Hurricane Ernesto, although the Veracruz state civil defense office said none of the region's numerous rivers had overflowed. Some streets flooded in low-lying neighborhoods of the port city of Veracruz.

The U.S. National Hurricane Center said the depression had winds of about 30 mph Saturday afternoon. It was 65 miles west-northwest of Tampico, an oil-refining center and important port in Tamaulipas state. The city with about 790,000 inhabitants sits just above sea level and is surrounded by lakes and lagoons vulnerable to flooding.

Helene was moving west-northwest at 5 mph, and was expected to dissipate Saturday night or early Sunday.