Two atmospheric rivers are forecast to make landfall over California, bringing heavy rain and snow accumulations across Southern California from late December through the first week of January.
The first AR made landfall along the Southern California coast late on December 30, driven by a subtropical moisture plume extending from the eastern North Pacific and strengthened by a mid-level cutoff low. Integrated vapor transport (IVT) values are forecast to reach moderate levels, with CW3E’s West-WRF model forecasting AR 2 intensity over coastal San Diego County.
Freezing levels during this first event are expected to remain near 3 650 m (12 000 feet) across the southern Sierra Nevada, leading to primarily rainfall rather than snow…