Prior to final intercomparisons of the reengineered WVSS systems with raobs, 224 WVSS observations obtained from aircraft on the ground were compared with contemporaneous aviation routine weather report (METAR) surface observations at 43 airports across the contiguous United States (CONUS) and southern Canada (Petersen et al.
WVSS EVALUATION DESIGN AND RAWINSONDE COLOCATION RESULTS.
Comparisons of WVSS reports with collocated raobs were obtained during 16 evenings over three separate observing periods in fall 2009, spring 2010, and summer 2010 at the Rockford, Illinois, airport (RFD).
The first launches were made immediately before a period when a group of WVSS equipped aircraft landed and the last immediately after the final aircraft departed, with intermediate launches made during the short period between the last landing and first departure.
Before statistical analyses were performed, individual WVSS systems were compared with nearby raobs.
Figure 4 shows differences between an individual WVSS equipped aircraft and raobs throughout the spring 2010 data collection period.
By contrast, the WVSS SH reports show little bias and very small random differences in the lowest 200 hPa of the profiles.
Comparisons between aircraft and individual raobs provide another subjective means of evaluating observations from individual WVSS equipped aircraft.
5b) was also very good, as illustrated by the fit of the WVSS data between the bounding raobs across much of the strong low-level moisture inversion in this summer case (see Fig.
WVSS observations were compared both with the single closest-time raobs and with bounding raobs interpolated linearly at each level to the aircraft observation time.
Because the objective of these evaluations was to determine the quality of the WVSS data, in situ observations in which the effect of small-scale, local atmospheric variability was minimal were sought for comparison.
Figure 6 compares individual WVSS reports with the collocated raobs for all levels, all observation periods, and both ascents and descents.