1. Ship waves atop severe storms

2. What causes ship waves?
Ship waves are not pure waves but are due to the interference of waves.
They are caused by the relative motion between the fluid and an obstacle

3. Diverging mode and transverse mode

4. Kelvin’s simple solution for infinitely deep water and point disturbance

5. You don’t need a real ship

6. This means that …
As long as there is relative motion between a fluid and an obstacle in it, ship waves may be generated
But these waves do not necessarily look like the Kelvin solution! (though many do look like that), e.g., Karman vortex streets
Conversely, if we see ship waves in a fluid, then there must be obstacles in it.

7. Storm top ship waves
So if you observe ship waves at the top of a storm, it should mean that there are obstacles in the storm
This “obstacle effect” has been a long time controversy in the severe storm community. Some say it exists and others say otherwise.
But previous studies were based on observations of wind fields “around” the storms and not inside the updraft core of the storm.

8. Satellite examples