Weather Talk: Lessons to learn from St. Paul school bus debacle
Many St. Paul students were stranded in school buses Monday, Jan. 22, some until almost midnight, when very heavy snowfall rates caused sudden snow accumulations. The big problem is that powerful winter storms often do unexpected things, so potential forecast error needs to be a part of any decision.
In this case, the general idea of a heavy snowfall for the Twin Cities area was well forecast. The heaviest accumulations were, as expected, south of the metro area, and the idea of a sharp cutoff to the north was anticipated.
But during the day, Monday, bands of extremely heavy snow produced accumulations of 2 inches an hour for several hours in a row. Central and southern parts of the metro area expecting 6 inches in 12 hours got 12 inches in about six hours. Plows simply couldn't keep up.
This is why a certain degree of "erring on the side of caution" is probably a good idea with winter storms.