Earliest accumulations began on September 8th and September 9th at the highest elevations (Joe Wright and Deadman Hill)., yet the highest elevations had some of the lower total accumulations for the duration of the storm.
The largest accumulating stations (located in the foothills) also started accumulating earlier than most of the other stations (Sugarloaf and Estes Park). In fact, the Boulder site (Sugarloaf) began large accumulations almost a full day earlier than all the other sites, on September 11th.
The largest accumulations at Boulder and Estes Park came overnight from Wednesday, September 11th into Thursday, September 12th.
The largest accumulations at the southern sites (Denver and El Paso County) occurred during the day and evening of September 12th.
All of the stations saw little to no accumulations for most of Friday, September 13th and early on Saturday, September 14th.
Greeley and others downstream have suffered many impacts from this storm, but as can be seen from this graphic, it was not due to heavy precipitation. Most impacts were due to flooding on many tributaries to the South Platte and the large spatial extent of this storm event.