Summary:
- September brought generally average to cooler than average* temperatures over much of the west coast.
- A shift to a more active trough pattern out of the Gulf of Alaska allowed low pressure areas to bring a wetter than average month to northern California and most of the PNW, while the systems did not reach the rest of California resulting in a very dry month.
- Drought conditions continue in the PNW and southwest. Conditions look good heading into the rainy season for California and the Basin.
- The dominant trough pattern of late September gives way to ridging over the first 10 days or so of October. A bump up in temperatures for pretty much everyone, even quite warm for some inland and southern regions. Dry conditions will allow the PNW to dry out, helping to complete the harvest.
- While mid-October looks potentially wet, the month on balance is forecast to be drier than average in the PNW and closer to average in California. Temperatures are forecast to be normal to above average over much of the western US, especially in the PNW.
- The 90-day forecast transitioning us into the first half of winter is largely holding to typical El Niño effects producing a warmer and drier PNW and slightly cooler and potentially wetter southern tier of states. However, the north and tropical Pacific Ocean basins are out of sync right now with a cold PDO conflicting with the strengthening El Niño. This often means that what we get will be very different from the expected effects. As such I am in a holding pattern on the seasonal forecast until we get a little further into the transition to fall and winter.
