You may have seen the widely circulated story that the local National Weather Service office has measured over 200 inches of snow this season as of Monday morning, February 25th. Unfortunately, some articles have explicitly assigned the total to Marquette. Others have allowed readers to conclude that this is a representative total for the area. In fact, the NWS office is located well outside of the city limits in the highlands which receive substantially more snow.
A helpful rule of thumb is that for every 100 ft you gain in elevation, you can expect 10 additional inches of yearly snowfall.* Of course, there are other factors, such as differing lake exposure, that come into play in the wider area. For this comparison, however, elevation is the key difference. So, given that the NWS office is 800 ft higher than the lakeshore of Marquette, that represents approximately 80″ of additional snowfall per year. In fact, that’s very close to the 30 year normals. Marquette normally receives close to 120″, and Negaunee Township gets a little over 200″ per year.
So far this season (October 1 – February 25) in Marquette, the city’s official NOAA COOP weather station has recorded 96.3″. That’s less than HALF the amount the NWS office received. Just a mile away from the COOP station at our location, 3 blocks south of downtown, we recorded 108″ in that period. We are about 100 ft higher than the COOP station, which explains why we’ve had a bit more snow. To be more than fair, I would allow for an additional foot or so lost to high winds this winter at our station (which would give us about 120″).
So, in other words, both Marquette and Negaunee Twp have received something close to their normal seasonal totals thru the end of February. That would be the proper way to frame a story if, indeed, you were writing about Marquette.
Headlines vs. Science
I find it particularly troublesome that Northern Michigan University promotes the false claim. It’s true that pushing extreme weather burnishes the university’s brand (outdoor adventure, winter wonderland, etc) which helps in their recruitment and retainment of students. But what about NMU’s recent efforts toward greater STEM (science, technology, engineering, and math) access? How do you square ignorance or obfuscation of your campus’ climate with enhancing science education?
To be clear, the city has received an abundant amount of snowfall, particularly in February. The snow depth is quite high, at least in part, because temperatures have been so far below normal. Relatively little of it has melted. You don’t need 200″ of snow under those conditions to make the city a cavernous maze of snow tunnels.
Zooming out, the U.P. is a sequence of significantly different sub climates within close proximity. This is due primarily to the complex influence of the Great Lakes and a diverse topography. There is no one report that can be expected to fairly summarize the surrounding region.
Describing the city is hard enough. There’s the city core where the vast majority of residents live between about 600′ – 800′ elevation. Our weather station captures those conditions for the most part. There are also more outlying areas like the Marquette Golf Club or Presque Isle Park which have different temperature, wind and precipitation patterns. Even so, they share more in common with the city’s climate than Negaunee Township’s.
This website will surely never go viral by publishing a substantially lower seasonal snow total. Nevertheless, that’s the requirement of science which is, by definition, uninvested in a particular outcome.
Overall, a commitment to accuracy means:
- Arising early to measure snow, measuring throughout the day and late at night if necessary.
- Measuring immediately after it stops snowing to reduce loss by sunshine or wind.
- Deploying multiple snow boards to combat drifting.
- Disclosing when a measurement is in doubt.
- Weighing snow (to determine liquid equivalence) as this is the least error-prone method.
- Shoveling snow from the path to the measurement site even if it has drifts several feet high.
- Doing all of the above whether you feel like it or not or just want a day off or there’s only a fraction of an inch.
Sounds exciting, eh?
Truth be told, we have family in Arizona. We could spend several weeks of the winter there since my wife and I both work from home. We have a daily responsibility here, though. It’s upsetting to watch the rush toward a seductive story sideline and undermine a lot of hard work.
* Information courtesy of Weather Channel meteorologist Tom Niziol, from a CoCoRaHS webinar on Lake Effect Snow on November 12, 2015.
NOTE: I don’t link to example articles because doing so only promotes them within the search engines. If you click on the link to NMU’s tweet, you’ll see an example of what I’m talking about.