A rare combination of historic wet and very warm climate was observed AUG/SEP/OCT 2021 in the U.S. The wet/very warm pattern was propelled by anomalous warm SSTA off the Northeast U.S. Coast to the northern Atlantic.

The monthly Climate Impact Company ENSO Outlook indicates ongoing La Nina will strengthen, peak in DEC/JAN and dissipate by MAR/APR of next year. Typical of La Nina, a cool phase Pacific decadal oscillation coincides and enhances the La Nina climate.

Operational models indicate an amplified upper trough pattern that could initiate record-cool temperatures in the 11-15-day period across west/central Australia lingering for much of the remainder of November once established (according to ECMWF). The upper trough will cause widespread wetter than normal weather from northwest-to-southeast across Australia in November.

While “atmospheric river” and “bomb cyclone” are new meteorological expressions which were used to describe the potent West Coast storms over-the-weekend there are some climate diagnostics completely unique which helped two 943-947 MB low-pressure systems to form…one just southwest of Alaska last Thursday night and another due west of Washington Sunday morning.