April 28, 2020 – Dry weather with above normal temperatures continue through the middle of the week. Near record highs are expected today, with Valley locations in the 90s. Temperatures then begin a cooling trend, reaching back to normal by the weekend, with a slight chance of showers north of I-80.
Upper level ridge axis moves across the region today, the hottest temperatures of the week expected this afternoon. Highs in the Valley will be in the 90s, 15 to 20 degrees above normal. These could reach record levels in some spots. Sacramento Executive Airport is forecast to tie the record of 92, set in 2013. Redding and Red Bluff will be close to respective records of 93 & 94. A light north wind in the northern/central Sacramento Valley could bring a few locations there into the mid 90s.
The good news is the heat will be short lived, with onshore flow developing by early evening as the ridge axis shifts eastward. This will bring some cooling into Delta breeze influenced areas tonight. Lows in the Delta and Sacramento metro area are expected to be in the upper 50s, in the lower 60s elsewhere in the Valley, mid 60s in the foothills. The area will see more widespread cooling on Wednesday, with highs about 4 to 8 degrees cooler than those of today, in the mid to upper 80s.
A shortwave will pass to the north late Wednesday into Thursday. Precipitation is currently expected to stay north of Shasta County. Increased cloud cover and further cooling will be the main effects for the forecast area. Friday is expected to see Valley highs in the low 80s as a deeper trough from the Gulf of Alaska approaches.
Extended Discussion (Saturday through Tuesday)
Upper trough approaches NorCal Saturday and moves through Sunday. This will result in cooling with increased onshore flow. System modeled to bring a threat of precipitation, mainly north of I-80 with best chances in the foothills and mountains. Overall storm QPF looks light. Building high pressure will bring drier weather Monday and Tuesday with warmer temperatures.