Before the big storm warning, maybe the sea will be calm and a little scary until the wind and waves rise, that is, big winds and waves.
If birds like seagulls are oppressed by atmospheric pressure, they will fly very low and even stick to the water. If they were closer to the storm, they might not find any flying creatures. They are more sensitive than humans.
There will be dark clouds in the sky, that is, cumulonimbus clouds, which will move rapidly with the change of airflow. Sometimes they even cover the sky. It feels like night is coming.
On the island, you will find that all insects and animals have become abnormal.