Contaminated runway
I don't know about the B-737. However airports operations on loose snow and slush covered runways are treated in a similar manner as operations on a runway contaminated with standing water. The only difference is that because of different densities, a measurable depth of loose snow or slush must first be converted to an equivalent depth of standing water.
Do you have a table converting loose snow, slush into water depth?
Other type of contamination are treated with other tables.
Up to 3mm of water - WET (JAA)
Above 3mm of water & more than 25% - Contaminated (JAA)
Example:
35mm (1.38 in) of loose snow is equivalent to 12.2mm (0.48 in) of standing water.
You have then a runway surface contaminant in terms of equivalent water depth.
This number is then entered into the appropriate charts.
But before going further, what type of charts does Boeing provides?
Rgds.