Pneumonia front on Detroit River
© clickondetroit.com
Video taken Wednesday afternoon appears to show a waterspout forming over the Detroit River.

The video was shot from the Windsor, Canada side of the river.

It shows what looked to something like a waterspout forming and then dissolving. After review, it turns out this is not actually a waterspout. (Scroll down for the full explanation)

The video was captured by Salaheddin Rahal.


After posting the initial video, we received another view of the possible "waterspout" from Mark Steven.


After reviewing the footage, Paul Gross says this is actually NOT a waterspout. Here's the explanation:

What you are looking at was caused by a pneumonia front. Yes, you read it right: a pneumonia front. What's a pneumonia front? It's a fast-moving northeast to southwest moving cold front that is made even more impressive in the early spring due to the cold waters of the Great Lakes. The long cloud up in the sky that looks like a gray baguette extending from horizon to horizon is the leading edge of the pneumonia front.

I forwarded this video to my good friend Rich Pollman, Warning Coordination Meteorologist at our local National Weather Service office, and he offers some great insight to the waterspout-looking feature, filling in the many blanks I had because I was not at work that evening: "We had a lot of warm rain that evening falling into the very cold Detroit River. That created all of that "steam" on the Detroit River ahead of the cloud feature. You can see that moisture all along the Detroit River ahead of the "waterspout" and cloud feature, but no moisture behind it....The pneumonia front from Saginaw Bay and Lake Huron were both detected on the (Doppler Radar) that evening. The temperature fell from 72 to 54 in one hour at Port Huron when it moved through and Windsor and Detroit were in the mid 50s at 7 p.m. while Detroit Metro was still in the 60s (due to the rain)."

"The pneumonia front, like any other front, has lift and so you are seeing that "steam"/moisture along the Detroit River being gathered up and over the frontal surface in the inflow and lift portion of that front." In-other-words, the steam was being pulled upward from the water toward the cloud, and not extending down from the cloud to the river.

One of the big tip-offs in the video indicating that this is not a waterspout is the lack of any rotation around a vertical axis.

So there you have it: a remarkable example of a pneumonia front over downtown Detroit!

Waterspouts fall into two categories: fair weather waterspouts and tornadic waterspouts.

Tornadic waterspouts are tornadoes that form over water, or move from land to water. They have the same characteristics as a land tornado. They are associated with severe thunderstorms, and are often accompanied by high winds and seas, large hail, and frequent dangerous lightning.

Fair weather waterspouts usually form along the dark flat base of a line of developing cumulus clouds. This type of waterspout is generally not associated with thunderstorms. While tornadic waterspouts develop downward in a thunderstorm, a fair weather waterspout develops on the surface of the water and works its way upward. By the time the funnel is visible, a fair weather waterspout is near maturity. Fair weather waterspouts form in light wind conditions so they normally move very little.

If a waterspout moves onshore, the National Weather Service issues a tornado warning, as some of them can cause significant damage and injuries to people. Typically, fair weather waterspouts dissipate rapidly when they make landfall, and rarely penetrate far inland.

Take waterspouts seriously. If you are a boater or a person living along the coast of the Great Lakes you should be aware of their destructive potential. When warnings are issued for waterspouts, be prepared to quickly seek safe harbor, or to find shelter out of the path of the waterspout.