More sunshine with slight warming is expected Tuesday and Wednesday as the onshore flow weakens, followed by cooler temperatures and increasing marine layer clouds later in the week.
Short Term (Today-Thursday)
A trough to the northeast of the Central Coast is moving out, likely weakening the onshore flow. There may be some weak N-NE flow during the night and morning hours, but not enough to completely clear the evening marine clouds.
The main challenge will be predicting the behavior of the marine layer low clouds. Low clouds are expected to push into the coastal valleys tonight and Tuesday morning, but this push may weaken Tuesday night into Wednesday. Temperatures on Tuesday are expected to reach the 60s and low 70s in the coastal valleys, 50s to mid-60s at the beaches, and low 80s inland.
A new trough moving into the Pacific Northwest will impact the second half of the week. On Wednesday night and Thursday, stratus clouds will push inland again, causing temperatures to drop from the 80s back into the 70s on Thursday. Coastal temperatures will remain in the 60s due to the persistent marine layer. Despite night and morning low clouds, skies should clear each afternoon.
Long Term (Friday-Monday)
A broad upper-level trough will keep inland temperatures down on Friday and Saturday. A flat upper-level ridge will begin building on Sunday and Monday, leading to warming temperatures.
The marine layer stratus will continue to be the main challenge. On Friday and Saturday, expect the marine inversion to remain deep, with stratus pushing into the coastal slopes and slow afternoon clearing. This pattern will keep all areas a few degrees cooler than normal through Saturday. On Sunday and Monday, increasing mid-level ridging should limit the depth of the marine layer, resulting in rising inland temperatures. Coastal valleys will also warm, but the beaches may remain cool.
