Dr. Greg Jones recently published an updated weather and climate summary and forecast. This report looks back at November and forecasts conditions for December, January, and February.
Summary:
- The western US experienced a warmer than average* November, with the Basin and Rockies seeing the warmest conditions during the month.
- The forecast for precipitation in November, however, was a bust and clearly unforeseen in the seasonal outlooks. The result was a much wetter than average November in California and drier than average conditions in the PNW.
- Drought conditions have remained in the PNW and Southwest but are much improved in California. The problem is that much of the precipitation so far has been from rain, leaving an early season ‘snow drought’ across nearly all mountain basins in the western US. Concerned, yes, yet there is still time to make up snow deficits.
- A strong ridge centered just NW of California will bring mostly mild and dry conditions to the state, with the exception of prolonged tule fog in the central valley. The northern edge of the ridge is right at the OR-CA border, where strong moisture plumes will be able to move west to east and likely bring significant rainfall to the PNW.
- After a relatively warm forecast for the first 20 days of December, the last 10 days are forecast to experience cool to average or below average temperatures. The forecast also points to a wet north and dry south; however, conditions in November did not hold to this forecast, and I am skeptical about December as well.
- La Niña conditions are in place in the Tropical Pacific. This La Niña continues to be seen as a likely weak to mild, short duration event. But a strong negative phase of the PDO and a weak La Niña continue to tilt the odds to a cooler and wetter winter from northern California into the PNW, and cool to near average and dry into southern California and the southwest.
*Note that all references to normal or averages in this report are to the 1991-2020 climate normal for each weather/climate parameter unless stated otherwise. See this website for more information on climate normals.
View the report (PDF) on the Abacela website.
