North Shore Lake Superior

Strip Maps and 'Snow Rules!' grids

The project grid 'lookup'

To check if any observer is actively observing in a given 'cell', please check the lookup observer grid page (includes last year's data lookup).

The project grid design

The project will try to find a snow observer in each of 125 'observation cells'. Each cell is 10km wide along the shore and number 1 to 25 from Duluth to the Canadian border. Away from the shore the cells are lettered 'A' through 'E'. The cell at the shore ('A') is everything from .5km 'north' of highway 61 to the shore and into the lake. The other widths are also 'away' from the shore and have boundaries that parallel Highway 61. 'B' is .5 to 2.5km, 'C' is 2.5 to 6.0km, 'D' is 6 to 12km, and 'E' is 12 to 24km. The lookup of known observers to grid cells was last done on 9/22/04. A north shore map (300kb) with the grids shows cells that have observers shaded as pink. 'Zoomed-in' near-shore versions with lakes, observer locations, and with some roads labeled can also be viewed (all GIFs under 100kb each, WMFs are about 500k each)

Calculation of the 'strip maps'

The cooordinates of the north shore of Lake Superior were fit to a straight line plus a Gaussian 'bell curve' (a total of 5 coefficients). That very smooth representation was used as the 'straight edge' in preparing a 'strip map' of the entire north shore. A somewhat less smoothed version of the shore was used to form a series of 4 more detailed 'near shore' maps. (The lesser smoothing allows more land detail and somewhat less lake to be shown given for a given graphic height.) Those 'linearized shore' maps can be viewed/scrolled here.

Some features have been added to the maps.

From the 1:100k USGS topo maps:

From 1:24k USGS topo maps (LARGE:2.4mb each) ...

Snow Rules! main page
State Climatology Office, DNR - Waters, 2003
You can send email to the