Summary:
- Winter arrived with a much colder than average* November across the western US.
- After a wet start to November, precipitation amounts ended up largely below average for much of the west, although some areas in the inland PNW, southern California, the Great Basin, northern Rockies, and Plains did see a wetter than average month.
- Drought conditions have improved slightly, but the western US remains over 90% in some level of drought. The winter forecast points to drought improvement for the PNW but little change elsewhere in the west.
- The December forecast favors a continuation of the colder-than-average to average temperatures seen in the second half of November. The storm track does favor a wetter than average month for most of the west, but drier conditions are forecast the further south one goes.
- La Niña conditions continue in the Tropical Pacific with models pointing to the conditions staying in place through late winter to mid-spring, then transitioning back to neutral in late spring to early summer. With La Niña conditions in place and the negative phase of the PDO in place, the overall forecast continues to point to the PNW likely seeing a cooler/wetter winter, while California is more likely to be drier with near-average temperatures during the winter. The transition line is unknown, but it appears that the southern Oregon and northern California zone is the likely pivot point.
