Authorities are reporting widespreading damage and flooding in Donna, Weslaco and Mercedes.
Between four to six inches of rains have fallen in a short period of time.
But emergency management officials said the rains were accompained by strong winds and even funnel clouds causing much destruction.
Weslaco Emergency Management Coordinator George Garrett said winds destroyed four mobile homes off El Dora Road north of Donna.
Authorities are also responding to a fire off 12th Street and Business 83 in Donna.
Garrett said there is widespread flooding in streets of the Donna, Weslaco and Mercedes.
He told Action 4 News that some motorists are taking shelter in highway underpasses.
The Donna Police Department told Action 4 News that all land-based telephone lines are down except for 911.
Donna police said the city is experiencing widespread flooding and is asking area residents to only call in case of emergency.