IPM counting board debris map

Each week I removed the IPM counting board and drew the outlines of the counting board debris into my journal.  The debris consists of wax, pollen, propolis and other items like the occasional small hive beetle.  After cleaning off the debris, the counting board is returned to the hive.  I transferred  my journal debris maps into a spreadsheet grid where I (one or zero) scored the presence or absence of debris.  The debris mostly lands along blurry east-west lines which relate to the bee space between frames.  Probably most of the blurring of the debris is attributed to:

• debris falling off the bees as they bounce in and out of the hive entrances above the screen 
• debris bouncing or rolling on the screen
• debris moved by ants or wax moth larva beneath the screen on the counting board

To sharpen the debris map blurring, I used a moving 3 week sum which creates a debris map with three intensities.  All of my work is done twice, as I follow two side-by-side hives that were started this year. So, what story might describe these gnuplot contoured debris maps?

• In the beginning, the debris tends to be concentrated near the hive entrances which face west.
• Over may weeks the debris concentration moves east away from the hive entrances and also north.   The two hives consume syrup at different rates, have different flight activity and have different weekly debris maps.  However, both hives show the same overall shift of debris concentration when measured over many weeks. 

Where will I find the debris concentrated this fall?  What about this winter?  What about next spring?