Summary:
- Likely the warmest July on record for most of the western US. Temperatures 2-8 degrees warmer than average with the warmest conditions in California. Cooler along the coast, but still warmer than average.
- A dry July for most of the western US, except for inland thunderstorm activity from monsoon moisture streaming northward. However, less rain and more wildfire starts were the result of most of these storms.
- Growing degree-day accumulations ramped up in July with most western US wine regions now above average. Coastal zones and some inland areas of the PNW remain closer to average.
- After more seasonal temperatures to end July, another ridge of high pressure is setting in, bringing warm and dry conditions over most of the west. It doesn’t appear that this event will have either the magnitude of the record highs or the duration of those seen in July. Coastal zones will see onshore marine layers and fog that will likely tamp down temperatures.
- No widespread precipitation in the forecast through mid-month or further, although a slight chance exists in the far northwestern areas of Washington later in the month. Monsoon moisture will elevate inland thunderstorm potential for some but no real help in dampening the fires across the west.
- The 90-day forecast heading into fall has the western US with mostly above normal temperatures except along the coastal zones where onshore flow should keep conditions closer to normal. No clear precipitation outlook, with some indication of drier in the Rockies and southeast, and wetter than normal in the extreme PNW.
- The Tropical Pacific is now ENSO-neutral and La Nina conditions are expected by early fall. North Pacific coastal waters have warmed. Both would indicate a warmer than average end to the summer. The timing of the La Nina onset will likely determine the start of fall precipitation over the west.
