July 30, 2018 – Smoke will help to keep daytime temperatures cooler the next couple of days. Then a gradual decrease in high temperatures mid week returning to near average.
Discussion (Today through Wednesday)
The upper level ridge will slowly push east and south on Monday as a trough pushes into the PacNW. This will keep quiet weather in place with smoke being the main concern. HRRR smoke shows similar smoke conditions to what we saw on Sunday.
Widespread smoke is expected throughout the valley and mountains by the afternoon. This will also make the temperature forecast quite difficult, smoke will likely hold temps down but if we see breaks in the smoke temps will warm quickly in those locations.
The Delta breeze should bring some relief in the smoke to the Delta region and the Sacramento area during the evening and overnight. Models do push monsoon moisture back north starting late Monday but it remains to the east of us. This will keep the thunderstorm risk out of our area during the short term period.
Zonal flow develops by mid week as the upper level ridge continues to push to the east and this should bring a slight cooling trend with highs returning to near normal although the wildfire smoke will likely continue to make for a difficult temperature forecast.
Extended discussion (Friday through Monday)
Little change is expected through the extended period with upper level ridging being flattened at times by disturbances. Temperatures are expected to remain a little above average, though wildfire smoke could bring cooler temperatures if it remains widespread. Dry weather is expected to continue through the extended period at this point.
The European model is hinting at a fairly strong trough by Tuesday/Wednesday, though, which could bring the potential for some precipitation into NorCal. The GFS has a slower and weaker trough. Confidence is very low at this point, so will have to wait and see if there is any continuity/consistency in future model runs.