PRECIPITATION AT OCEAN WEATHER STATION-P

This paper examines the 27-yr record of precipitation measurements at Ocean Weather Station ''P'' (50-degrees-N, 145-degrees-W). The credibi lity of the rainfall observations is assessed, and the testing of cert ain extraordinary features of the fall and winter seasonal precipitati on time series is outlined. Using the portion of the record establishe d to be close to ''ground truth'' (1954-1967), the authors have statis tically related present weather observations to seasonal precipitation amounts at Ocean Weather Station ''P.'' With this approach, the autho rs have reproduced the first half (1954-1967) and predicted the second half (1969-1980) of the precipitation time series to compare to obser vations. Precipitation is physically estimated by determining the vert ical moisture convergence at Ocean Weather Station ''P'' and comparing the relative consistency of the moisture convergence time series to t he contemporaneous seasonal rate of measured precipitation. The analys is suggests that the Ocean Weather Station ''P'' record of measured pr ecipitation is a substantial improvement over previous estimates of pr ecipitation in the northeast Pacific for the period between 1954 and 1 967, but that the second half of the record, particularly during the e arly 1970s, remains questionable. Reliable rainfall estimates along wi th measurements for the 27-yr record are given to aid studies dealing with energy balance calculations and the verification of oceanic preci pitation generated by global climate models.