Figure 1: Release 1a versus Interim.

(a) Weekly numbers of reports for Release 1a (solid) versus the interim products (dashed). The dotted curve shows 1985-92 Release 1a counts adjusted for better comparability with the interim counts by reduction of NDBC data to 3-hourly values (hourly NDBC data were included in the interim products for 1980-84). Sharp downward spikes in November 1986, especially in the interim data, represent a gap in the NMC data archived at NCDC; it is hoped that it will be possible to eventually fill this and similar gaps with data from NCAR or other institutions.

(b) As for Figure 1A, except weekly numbers of ship reports for Release 1a (solid) versus the interim. Prior to 1984 in the interim set, data from ships could not be fully differentiated from data from other platform types.