The GEONOR gauge at the DOT garage site did not indicate any precipitation for this
event. According to the LEDWI sensor and algorithm there was about 0.03 inches of
snow accumulation at the METAR site which is about a factor of 10 different from the
lab personnel observations at the Ames garage (Fig. 10.31). This difference may be due
to the extremely light snowfall during this time, which is difficult for any instrument to
measure, or due to differences in location.
Fig. 10.31. Estimated snow accumulation (inches) from the LEDWI
sensor located at the METAR site.
The forecasts of air temperature from the later 06 UTC 11 February run (closer to the
time of the blowing snow event) were good for the first ~24 hours, but they diverged
from the observations during the 24 hours following the blowing snow event (Fig. 10.32).
The winds increased significantly at ~15 UTC, 11 February and the forecast winds
matched those observed during much of the event (Fig. 10.33).