There are two main factors with a big storm that can related to flooding. Water falling down from the sky and water rising up with tides. Since Maryland has the largest area of coastline of any state in the US if you consider the entire Chesapeake Bay Shore, then we have a lot to cover with Coastal Flood Warnings. Rainfall will range on average 1 to 3 inches in our region with much more farther south. Some of that water could take more than 6 hours to peak after the rain on tributaries that drain into the Bay. Then we must consider that winds will be over 30 mph with higher gusts along the water. This will be from the east to northeast.
The steady easterly wind creates two other problems on the Bay itself:
- That is like water swaying back and forth in a bathtub. The Chesapeake is shallow and water does slosh on to the western shore with an easterly wind.
- Tidal surge. The push of water form the Atlantic does reach up the Bay, and that can take a few hours. Check out the slider below and see how the water from the Ocean pushes up the bay and can reach Baltimore as Ocean City and Norfolk get close to low tide. So there is not one time that fits all.
The one caveat is that the direction is not from the southeast, would will prevent water from draining out at low tide. But this will still be a problem.