Tropical Storm Debby makes second landfall in South Carolina as flooding continues

The video provides an update on various weather and geological events, including Hurricane Debbie's impact on the Southeast USA, causing heavy rains and flooding. The hurricane made landfall near Myrtle Beach and is expected to move north, affecting areas up to Canada. The video also covers an ice dam burst in Alaska and an earthquake near Japan. The forecast predicts continued rain and flood threats in North Carolina and Virginia.

How does the text describe the movement of the storm after it makes landfall?

What is the significance of the flood threat mentioned in the text?