The National Weather Service says a A lingering upper level low pressure trough and plenty of moisture in place will provide the Mid and Lower Valley another chance of showers and thunderstorms this afternoon.
Some of the thunderstorms could drop one to two inches of rain in a short time producing some localized flooding of streets and low-lying areas.
The heat index could surpass 100 degrees in many cities.
A flood advisory continues for the Rio Grande south of San Benito. Forecasters say there are chances for elevated river levels.
There is also a flood warning for west central Cameron County, east central Hidalgo County and southwestern Willacy County until 7 p.m. Sunday night
Emergency management and local law enforcement continue to report areas of flooding and road closures due to excessive standing water from the storms on Saturday night and Hurricane Hanna. Some areas have received 10 to 15 inches of rain this week.
Forecasters say the flooding is in the following areas: Harlingen, Elsa, Edcouch, Santa Rosa, La Villa, Laguna Seca, La Villa High School, Santa Rosa Police Department, Tierra Bonita, Santa Rosa High School, Grand Acres, Indian Hills, Satiago Garcia Elementary School, Yznaga, Edcouch Volunteer Fire Department, Edcouch Police Department, Edcouch City Hall, Ratamosa, Edcouch-Elsa High School and Mila Doce.