'River-effect' snow

Question

Earlier this year 'river-effect' snow was reported in the Quad Cities (Western Illinois) along the Mississippi River. Per the local news report:

According to Andy Ervin, a Meteorologist with the National Weather Service, "You need an environment supporting flurries to get saturation for the enhanced snow showers. Air gets channeled between the bluffs and resides over the water at least 45 minutes to pick up the enhanced instability. Thus, you won't see this if winds increase, change direction, or we lose the cold air aloft."

I have only found two other short articles of 'river-effect' snow which occurred along the Missouri River in South Dakota and over the Ohio River in Cincinnati. Both of these events occurred in 2014.

My question is if there are any other reports of this phenomena world wide and has there been any research published?

Answer 1

This effect seems to be similar to the "lake effect snow". The main difference between those two effects is the body of water involved hence the difference in name.

In rather general terms: The cold air picks up moist air above the relatively warm body of water (being a river, lake or the sea). To achieve a significant amount of snow fall the air mass has to be a fairly long time above the water ("at leats 45 minutes", stated in the question). This is the main reason why "river effect snow" is not too common. "Lake effect snow" (describing again basically the same process) is more common, since the conditions (airmass crossing a lake (or the sea) for at least 45 minutes) are more often met.

According to Wikipedia lake effect snow occurs on the whole of the Northern hemisphere (where temperatures during winter get cold enough for snow fall) in proximity to sufficiently large bodies of water. Especially the coasts of the North Sea, the Baltic Sea, the Black Sea and the Sea of Japan. Apparently Istanbul is very prone to lake effect snow and experiences it basically each winter.

Quite some research on the lake effect snow was done during the past decades:

• Peace and Sykes, 1966
• Kelly, 1981
• Niziol, 1987
• Niziol et al., 1994

The publications by Niziol (and collaborators) focus on the forecasting.

Answer 2

I live along the Missouri River near Jefferson City MO. I've lived here since 1983.

There has been a couple of times in the past where my town experienced blizzard like conditions where between 18 to 24 inches of heavy wet snow was dropped overnight.

These events were confined locally to the river valley. Go North or South and the amount of snow dropped off quickly.

During both of those events we experienced thundersnow.