The East Atlantic/Western Russia (EAWR) index is present when a strong trough is located across Europe and north of China while amplified high pressure zones occupy the central North Atlantic and Caspian Sea region. In this pattern, which developed over 1 week ago and is forecast to remain through the next 2 weeks, heavy precipitation stretches across Europe.

The semi-permanent Amundsen Sea low pressure area emits low-pressure systems northeastward in the current weather pattern. The low-pressure systems are unusually strong featuring 970-980 MB low pressure. Attendant cold fronts extend to Southeast Brazil from these storm systems triggering heavy rains for that region in November.