Duluth (The Orographic City) Local Influences

* Geographic and topographic maps created from the USGS/ESRI ArcGIS mapping software and database

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 from 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 south. Much of Duluth is built on the side of the ridge along the North Shore. Some of the city and surrounding communities are on top of the hill. Some of the city also sits on a narrow strip of flat land at the bottom. Elevation within the city rises abruptly 600 to a little over 800 feet from the lakeshore to the top of the hill. The elevation at Duluth International Airport is 818 feet higher than at Sky Harbor Airport based on heights relative to mean sea level.

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 effects 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 called 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 from 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) of the University Corporation for Atmospheric Research (UCAR).

American Meteorology Society's Glossary of Meteorology

Additional references are included with some of the individual entries.