CORPUS CHRISTI, Texas (CBSDFW.COM/AP) – A downgraded Hanna continued weakening on Monday, but its remnants still threatened to bring rainfall and flash flooding to waterlogged parts of South Texas and Northern Mexico that have been dealing with a surge in coronavirus cases.

Now a tropical depression, Hanna was 65 miles north of Fresnillo in the Mexican state of Zacatecas as its winds weakened to about 25 mph, the National Hurricane Center said Monday.

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Initial reports indicated Hanna dumped up to 15 inches of rain in some areas in South Texas.

Hurricane Hanna in South Texas (credit: KTRK)

Another 1 to 2 inches could fall on Monday in areas of South Texas that are already water logged. The northern Mexican states of Coahuila, Nuevo Leon and Tamaulipas could see an additional 4 to 8 inches of rain, possibly producing mudslides in these areas.

Border communities whose health care systems were already strained by COVID-19 cases — with some patients being airlifted to larger cities — continued grappling with Hanna. There were no immediate reports of any deaths on either side of the border.

Coastal states scrambled this spring to adjust emergency hurricane plans to account for the coronavirus and Hanna was the first big test.

Gov. Greg Abbott announced Sunday the Federal Emergency Management Agency approved an emergency declaration that will provide federal aid.

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Hanna blew ashore as a Category 1 storm late Saturday afternoon with winds of 90 mph not far from Port Mansfield, which is about 130 miles south of Corpus Christi.

Myrle Tucker, 83, tried to ride out the storm in a powerboat docked in a Corpus Christi marina. But winds and rain blew out the vessel’s windows. Eventually rescuers in a dinghy were able to reach him and bring him to shore. Many other boats were flooded and lashed by the storm.

More than 65,400 customers remained without power on Monday throughout South Texas, including Corpus Christi, Harlingen and McAllen, utility officials said. That was down from a peak of 200,000 early Sunday morning.

Corpus Christi is in Nueces County, where 60 babies tested positive for COVID-19 from July 1 to July 16. Farther south in Cameron County, more than 300 new cases have been reported almost daily for the past two weeks.

The past week has also been the county’s deadliest of the pandemic.

Hanna came nearly three years after Hurricane Harvey blew ashore northeast of Corpus Christi, killing 68 people and causing an estimated $125 billion in damage in Texas.

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(© Copyright 2020 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)