More smoke but also more cooling

August 1, 2018 –  Smoke will help to keep daytime temperatures cooler the next couple of days. Cooling trend for the second half of the week into early next week.

Discussion

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A cooling trend is expected the rest of this week as upper level ridging shifts eastward while an upper trough moves into the Pacific Northwest. Afternoon high temperatures will be similar to those on Tuesday, a little above normal levels, with the coolest locations in Delta breeze influenced areas.

Smoke will again be a factor and will add a little additional cooling, especially in areas near active wildfires. Onshore flow will bring additional cooling across the area on Thursday. Valley temperatures over the next few days will generally peak in the 90s, near 100 around Redding. Temperatures cool a further on Saturday, a little below normal levels.

Wildfire smoke continues to affect air quality. AirNow air quality measurements at 2 am showed some areas with Unhealthy levels. Limit outdoor activity today if possible. HRRR Smoke model suggests that the Delta breeze may locally bring some cleaner air through the Delta and into adjacent areas. For current conditions and air quality forecasts, go to Airnow.gov.

Monsoon moisture is expected to be south and east of the area and will keep thunderstorm chances out of the forecast.

Extended Discussion (Sunday through Wednesday)

Dry weather with a gradual cooling trend is expected through the weekend into next week as upper level ridging is flattened at times by a series of disturbances. Temperatures will drop to within a few degrees of normal, with Valley highs in the 90s.

Wildfire smoke could also continue to impact visibility and air quality. Models are suggesting that a deeper trough approach the West Coast next week, but forecast confidence is low in the details.