With tropical storm Hanna strengthening and heading towards South Texas to make landfall on Saturday, residents from communities residing in the southern part of the state were urged to evacuate on Friday.

The storm is expected to bring heavy rain and hurricane winds this weekend and is likely to make landfall nearly 50 miles (80 km) south of Corpus Christi, Texas. Expected to hit as a Category 1 hurricane, Hanna will bring along winds of at least 74 mph (121 kph).

Possible Flooding And Call for Voluntary Evacuation

If the eighth-named storm this year becomes a hurricane it would be only the second this season to make landfall along the US Gulf of Mexico, after Cristobal which hit Louisiana in early June. Hanna could bring a life-threatening storm surge and flash flooding. It is expected to drop up to 15 inches of rain in pockets of southern Texas and northeastern Mexico, the US Weather Service said.

Representational Picture NASA Worldview

Kleberg County, south of Corpus Christi, warned residents of Loyola Beach, Ricardo and Riviera, Texas, of possible flooding and called for a voluntary evacuation. The storm is not expected to impact offshore oil and gas production. Energy companies were continuing normal operations and had not evacuated workers or shut down production from their Gulf of Mexico platforms because of Hanna.

Three Petroleum Refineries In Hanna's Path

Chevron Corp and Royal Dutch Shell Plc ruled out a significant impact on operations in the US Gulf of Mexico, spokespeople said. "The tropical storm has had no impact on Murphy Oil's Gulf of Mexico operations given its weakness and location in comparison to our assets," added Murphy spokeswoman Megan Larson. BP said Hanna was west of the company's offshore production south of Mississippi and Louisiana.

Corpus Christi, near where the storm is expected to hit on Saturday, is home to three refineries. The largest, Citgo Petroleum Corp, intends to keep its 167,500 barrel-per-day (bpd) refinery in Corpus Christi operating as the storm passes to the south, people familiar with the matter said. The others, Valero Energy Corp and Flint Hills Resources, did not reply to inquiries.