HOUSTON (CW39) – Ida is now a tropical storm after entering a favorable environment for intensification overnight. Louisiana is now bracing for a hurricane as we head into the weekend. Impacts include: strong winds, heavy rains, and storm surge.
What causes storm surge?
Storm surge is the abnormal rise in water levels due to an approaching tropical storm or hurricane. Storm surge can be dangerous due to its ability to inundate residential areas quickly, leaving little time to escape. This “wall of water” can travel far inland, not just impacting immediate coastal regions. During Hurricane Ike the storm surge traveled 30 miles inland for some locations along the Texas coast.
The low pressure that forms in the center of a storm pulls the water upwards. This creates a “bulge” in the ocean. Like a bubble. That, along with the high winds pushing the water along shore, creates a situation that only allows for the water levels to rise. It has nowhere else to go but up and inland.
Why do we see marine impacts, and rising waters outside of the cone?
Even if your area is not directly hit by a storm you may still experience marine impacts. Why? All of our rivers, bayous, estuaries, and swamps are connected to the Gulf of Mexico, and that is where the storm is. The forward propulsion of the storm will increase waters all along the coastline. The curve of the land, whether it is high tide, and distance from the onshore flow are the two biggest factors.
For example, think about tipping over a bucket of water on the kitchen floor. Where the bucket falls is where the water will dump out the most and with the most force. However, with a little time the water starts to spread much further than where the bucket fell. Now you have a big mess to clean up. Water may have ponded up a bit more in the corners of your kitchen. This represents a concaved area of coastal land such as a bay. Bays also see higher storm water inundations because the same amount of water is getting squeezed into a smaller surface area. When water can spread horizontally, it goes up!