May 8, 2018 – Dry and warm weather continues. A few showers or thunderstorms are possible across northern mountains later today and tonight. Well above normal temperatures are expected late this week.
Discussion
High pressure ridging is over the region, with the ridge axis shifting eastward into Nevada. Mostly clear skies are present across the area early this morning, except for some high clouds passing over the northern mountains and northern Sacramento Valley. Temperatures are warmer than yesterday at this time by about 3 to 9 degrees. Highs this afternoon will be similar to yesterday, just a degree or 2 lower.
Cloud cover will increase some later today as a weak shortwave trough brushes through far NorCal. This system could bring some light showers and a few isolated thunderstorms over the northern mountains and northern Sacramento Valley this afternoon into the evening. Only light precipitation amounts are expected. Most of the instability is elevated, with low levels being rather dry. The main threat with any thunderstorms that develop are gusty winds, with evaporative cooling and the mixing down of stronger winds aloft.
Winds through the Delta should increase later this afternoon and evening and become breezy to locally windy. Sustained winds up to25 mph are possible in the Delta, with gusts up to around 35 mph.
Cooler temperatures are forecast for Wednesday. The Delta and Delta should see highs remaining in the 70s, with low 80s across the Valley.
Warmer weather is expected on Thursday, with highs 5 to 10 degrees above normal. Valley locations expected to be in the mid to upper 80s with mountain highs in the 60s and 70s.
Friday looks quite warm, with widespread mid to upper 80s and some spots approaching 90. Breezy northerly winds winds are expected as high pressure builds to the north and an upper low moves southward into the Great Basin. Gusts to 30-40 mph are possible in the central Sacramento Valley. A Wind Advisory may be needed, with potentially difficult driving conditions for high profile vehicles.
Extended discussion (Saturday through Tuesday)
Trend in the models has been slower with moving out the Great Basin/Rockies trough next weekend. If the trend persists, may need to introduce some pops for the northern Sierra Nevada and southern Cascade Range. Temperatures will be above average with highs across the Central Valley ranging from the 80s to lower 90s.