Keweenaw snow invisible to weather monitoring

Kali Katerberg/Daily Mining Gazette A snowman stands near the Portage Lake District Library surrounded by fresh, powdery snow.

HOUGHTON — As its residents know, the rapidly changing weather of the Keweenaw Peninsula can be difficult to predict.

Radar difficulties, shallow clouds and high variability between regions are a few of the disrupting factors.

Snowfall researcher and Michigan Tech assistant professor Mark Kulie highlighted a few of these issues at a Tuesday presentation at the Carnegie Museum.

“This is a fantastic local laboratory to study snow in,” Kulie said. “It defines life here throughout the winter months.”

Snowfall can be impacted by ice coverage, elevation and types of snowflakes.

“If you live in the Lake Superior region, every once in a while the lake freezes up and that lake-effect machine shuts off,” Kulie said.

The ice cover impacts how much snow an area gets, adding extra variability.

With the range of terrains and factors, predicting snowfall for a given area can be complicated. Particularly since radar can have difficulty dealing with snowflake diversity, making it difficult to determine snowfall rate without additional observations, Kulie explained.

Even the clouds can make radar difficult to rely on.

“We typically associate intense precipitation with deep cloud structures. The problem of lake-effect snow is you can get very intense precipitation from very shallow cloud structures,” Kulie said.

Those shallow clouds can evade radar detection.

“We never see any signatures of lake-effect snow from the Marquette National Weather Service radar,” Kulie said. “There are two reasons for that. One is, these are very shallow cloud structures, and this radar is scanning slightly upwards. The further you are from the radar the more it’s going to overshoot those very shallow structures.

The second issue is a slight ridge to the north of the weather service station that partially blocks the radar from seeing the northwest, Kulie explained.

“It’s a horrible coincidence for the Keweenaw Peninsula, that radar is basically a wash,” Kulie said.

The radar will start to pick up clouds near Ontonagon, usually signaling heavy snowfall on the rest of the Keweenaw, which often is invisible to the radar.

Kulie is working to better predict and measure these snowfalls.

“When you think about it, … complexities are opportunities, this is where science moves forward,” Kulie said.

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