NUEVO LAREDO, Mexico, Sept 7, 2010 (AFP) - Powerful Tropical Storm Hermine slammed into far northeastern Mexico and then barreled into US territory early Tuesday, threatening storm surges, flash floods and tornadoes on both sides of the border.

Hermine churned ashore bringing torrential rains at around 8:30 pm (0130 GMT Tuesday) along the Gulf of Mexico coast, in Mexico's Tamaulipas state south of the city of Brownsville, Texas, the US National Hurricane Center (NHC) reported. By 0600 GMT, top sustained winds for the eighth named storm of the Atlantic hurricane season had decreased slightly to 95 kilometers (60 miles) per hour and the storm was moving toward the north-northwest at 22 kilometers (14 miles) per hour. Although it did hit the coast as a "strong" tropical storm, "additional weakening is forecast and Hermine is expected to weaken into a tropical depression by Tuesday afternoon," the Miami-based NHC said. Hurricane watches were discontinued for the Mexican and Texan coasts, along with a tropical storm warning south of Bahia Algodones, Mexico, but tropical storm warnings were in effect on both sides of the border. At 0600 GMT Hermine's center was just north of the Rio Grande, the US-Mexico border river, and wind gusts up to 111 kilometers (69 miles) per hour were buffeting the Brownsville/South Padre Island International Airport, NHC said.

The storm is expected to continue moving inland Tuesday and into central Texas early Wednesday after it weakens to a tropical depression. Forecasters said the system would dump between 10 to 20 centimeters (four to eight inches) of rain on northeastern Mexico and south Texas, with up to 30 centimeters possible in some places. "These rains could cause life-threatening flash floods," the center warned. It said a storm surge of up to 1.2 meters (four feet) was also possible, as well as "isolated tornadoes" along the lower and middle region of the Texas coast. Tamaulipas authorities urged residents under threat to move to the more than 90 shelters set up in the state, and they evacuated about 3,000 people in the cities of Matamoros -- which borders Brownsville -- Valle Hermoso, Rio Bravo and Reynosa, said state civil defense director Salvador Trevino.

Mexico's northeast cattle-ranching region was hit hard in July by Hurricane Alex, which caused serious flooding that left 22 people dead and 40,000 homeless. The region is a common transit area for illegal immigrants from Mexico and other parts of Latin America, and late last month 72 migrants making their way toward the United States were slaughtered on a ranch in Tamaulipas in one of the worst acts of drug gang violence in years. In southern Mexico, floods have killed at least three people and forced nearly half a million from their homes since the weekend, authorities in Oaxaca and Guerrero states said. Hermine is the latest storm to form after Hurricane Earl, which gained category four status at its height in the Atlantic Ocean, whipped up heavy winds along the east coast of the United States and Canada.

Earl weakened dramatically after making landfall in Canada on Saturday as a category one hurricane but Nova Scotia Power said 80,000 homes were without electricity on Sunday.

bur-oh/mlm