April 16, 2021 – A few late day showers will be possible over the northern Sierra over this afternoon, otherwise dry and warm weather through the weekend. Temperatures will warm to the upper 80s to low 90s by Sunday for Valley communities.
Discussion
Omega blocking pattern setting up over the Eastern Pacific and West Coast will keep dry and progressively warmer conditions over NorCal heading into the weekend. The only exception will be isolated showers over the Sierra this afternoon, as this area is on the western edge of trough over the Great Basin undercutting the ridge. Best shower chances will be from the upper foothills to about 5000 feet.
Valley high temperatures will generally be in the low 80’s today, mid 80’s Saturday and near 90 Sunday. Highs will be in the upper 70’s to low 80’s foothills and lower mountains heading into the weekend. Area waterways will remain much colder than the air temperatures due to snow melt, please use caution near waterways.
Short range ensemble and clusters are in good agreement with blocking pattern breaking down Monday, as strong reinforcing trough drops south over the Rockies. This will lead to slight cooling with Valley high temperatures falling back into the low 80’s.
Extended discussion (Tuesday through Friday)
Models continue to differ with depth and track of upper lows Tuesday into Thursday. Available moisture is limited and NBM trending drier on Tuesday. Models similar in generating some potential precip over the Sierra Nevada Wednesday. Forecast leans toward drier upper ridging towards the latter part of next week. Locally gusty north to east wind possible at times Tuesday into Thursday. High temperatures remain about 10 to 15 degrees above normal through the extended forecast period.