Summary:
- December continued the warmer than average* start to the winter for the western US and likely helped cement 2023 as one of, if not the warmest years on record globally.
- December was also quite dry over much of the western US with only coastal zones in central California, portions of northern Oregon, and most of Washington receiving greater than normal precipitation for the month.
- While still drier than most would like, drought conditions have continued to improve over the western US.
- Mild to seasonal temperatures to start 2024, turning cold for most of the west through mid-month but January likely ending up near average for the west coast. Precipitation is forecast to be average to slightly above average for the month, although a little drier north and a little wetter south is anticipated.
- The Tropical Pacific remains in El Niño with a 54% chance of a “historically strong” event during the winter. These conditions are likely to persist into early summer and then transition to ENSO neutral. The North Pacific has warmed some but still remains out of phase with the warmth in the Tropical Pacific. The seasonal forecast is dominated by El Niño; however, I still think there is some wiggle room in the forecast for atypical conditions, especially later in the winter.