Fig. 1: Two Atmospheric River events in February 2020.

The vertically integrated horizontal water vapour transport (IVT; shaded contours) and mean sea-level pressure (black line contours) in the analysis of the European Centre for Medium-Range Weather Forecasts (ECMWF) control forecast at (a) 00UTC 5 February 2020 across the northeast Pacific Ocean and (b) 00UTC 16 February 2020 across the North Atlantic Ocean. The Atmospheric River (AR) in a was sampled as part of AR Recon and the black dots overlaying the thick black lines correspond to the dropsonde locations and the aircraft flight track out of Portland, Oregon, respectively.