Duluth (Orographic City) Local Influences

Duluth is located at the narrow western tip of Lake Superior along a ridge that runs along the north shore of the lake. The Lake Superior north shore is oriented from east-northeast to west-southwest. Elevation increases abruptly near the lake shore on both sides of the lake. The city of Superior, WI, across the harbor from Duluth, is generally flat but the hills are just off to the southeast. Duluth is built partially on the side of the hill. Some of the city sits on a narrow strip of flat land at the bottom while the rest extends inland past the ridge crest. Elevation within the city rises abruptly 600 to a little over 800 feet from the lake shore to the top of the hill. The elevation at Duluth International Airport is 817 feet higher than at Sky Harbor Airport.

Lake Superior and the surrounding higher terrain greatly influence weather conditions in the city. People unfamiliar with Duluth may be surprised at how much the rise in elevation acts like a mountain range concerning its affects on weather. As a friend once told me, "But, it's just a little hill!" Apparently it is not. The influences on weather are mostly mesoscale in size meaning they act over a distance ranging from several miles to several hundred miles. Weather processes and events occurring over larger distances are synoptic scale. Those occurring over smaller distances are microscale. Seasonal snowfall and snowfall during many individual storms varies greatly within the city. Seasonal snowfall on top of the hill averages 80 or more inches. Averages at the bottom of the hill are generally 20 inches less than at the top.

Increasing Duluth's Snowfall...Good!

Decreasing Duluth's Snowfall...Not Good

Other Local Influences

General References

Personal Communications (2001 to 2006) with Employees of the National Weather Service in Duluth, MN

Meteorological Education and Training (MetEd) website operated by the Cooperative Program for Operational Meteorology, Education, and Training (COMET�) at http://meted.ucar.edu/ of the University Corporation for Atmospheric Research (UCAR).

American Meteorology Society�s �Glossary of Meteorology�

Additional references are included with many of the separate entries.