Residents along the coast can expect a persistent marine layer throughout the weekend, thanks to a strong onshore flow across the area. This weather pattern will bring night through morning low clouds and fog, which will struggle to clear from the coast each afternoon. However, there is a possibility of better clearing and slight warming next week as the onshore flow could weaken.
Short-Term Forecast (Today-Monday)
A long wave trough along the West Coast will remain in place into early next week, supporting a deep marine layer, areas of morning drizzle, and sluggish afternoon clearing, particularly for some beaches and coastal valleys.
Today, there was a "reverse clearing pattern" where inland areas cleared later than the beaches and coastal valleys. With the potential further deepening of the marine layer over the next couple of nights, this trend may extend to more coastal areas and parts of the coastal valleys. Predicting the exact clearing pattern this weekend is challenging, but temperatures are expected to stay cool.
On Monday, the trough will deepen along the coast, pulling in a secondary upper low from the southwest. This will likely further deepen the marine layer, possibly bringing more extensive morning drizzle and lower chances of afternoon clearing.
In the deep interior areas, skies will generally remain clear, though some stratus clouds might reach parts of the SLO County interior and the Cuyama Valley. Temperatures in these regions will be a few degrees above normal, with gusty west to southwest winds expected each afternoon.
Long-Term Forecast (Tuesday-Friday)
Looking ahead to the long term, the onshore flow is expected to weaken on Tuesday and Wednesday following the passage of the long wave trough along the West Coast. This should result in earlier marine layer clearing and warming in the interior valleys and some coastal valleys.
However, this improvement may be short-lived. Models indicate another upper low could drop out of the Pacific Northwest late in the week. A series of such troughs over the next few weeks may keep temperatures below seasonal averages.
