The May gray pattern remains, with night to morning cloud cover along coastal and valley areas. Interior valleys will warm above average through Thursday, then slightly below average through the weekend.
A weak upper level ridge will shift more easterly on Thursday, with strengthening onshore flow. This is due to a weak low pressure system over the Pacific Northwest expected to sink further south through the weekend.
The trough will develop into a cut off low by the time it arrives in California on Saturday. This are of low pressure will stay parked over the weekend, prompting cooler temperatures and more cloud cover. With stronger onshore flow this will also create a deeper marine layer, with the chance of drizzle or light rain especially across foothills. Otherwise conditions are likely to remain overcast, with little to no clearing at all. Temperatures this weekend will warm 50s to 60s along the coast and 60s to 70s inland.
The trough will shift east late Sunday with a slight warming trend on Monday and Tuesday. The marine layer is likely to clear quicker as the low should have shifted more easterly. Along with warmer air moving along the western portion of our state.