July 5, 2018 – July 5, 2018 – Warming trend begins today and continues into next week. Smoke near wildfires and hazy conditions at times elsewhere.


Clear skies prevail across interior northern California this morning under dry southwest flow aloft. A slow moving low pressure system off the Pacific Northwest coast continues to bring a modest Delta Breeze today, albeit not as strong as the last couple of days. The marine layer moved inland as far as Grizzly Bay in the Delta this morning.

MODIS and IR Satellite imagery suggests that the County Fire didn’t burn as intensely last night as the last few. As such, the density and coverage of smoke has diminished a bit.

High pressure centered over the central US will begin to retrograde westward today, bringing warmer temperatures to the region. Look for highs in the upper 80s to lower 90s across the Valley, with 80s for the foothills and 60s to 70s over the mountains. These forecast highs are around to slightly cooler than normal for this time of year. High temperatures will be similar Friday compared to today, then warm up a few degrees over the weekend as high pressure continues to strengthen. We’ll continue to see a Delta Breeze influence through the weekend, which will keep temperatures moderated. Look for highs in the 90s to 100 degrees across the Valley over the weekend.

Extended discussion (Monday through Thursday)

Warm and dry conditions anticipated across interior NorCal as ridge of high pressure remains in control. High temperatures are expected to be above normal early next week, but not excessively hot with upper 90s to 100s across the Valley and mid 70s to 90s over the foothills/mountains. Therefore, long outdoor exposures could increase chances for heat-related illness among sensitive groups on Monday. Temperatures will gradually cool down a few degrees closer to average by the end of the forecast period. Some moisture may advect northward late next week leading to thunderstorm activity over higher terrain.