11:03pm update from Dave Hovde:
Cold temps are a concern tonight for the interior of SLO County tonight. For the Southern Salinas River Valley frost is likely with temps getting near 32. The deeper interior will see these temps drop into the upper 20s long enough to potentially kill plants or damage unprotected outdoor plumbing:
Rest of Today:
Expect moderate north winds across the Central Coast, especially along higher elevations and coastal areas of Santa Barbara County. These winds result from a current upper-level low-pressure system centered along the Arizona-New Mexico border. This setup tightens the pressure gradient against a high-pressure area over the Pacific, driving north-to-northeast winds across Southern California. Winds should gradually ease as this low moves eastward into Tuesday. Temperatures will remain near seasonal norms, with daytime highs generally in the upper 60s to low 70s. Skies will stay mostly clear, adding to the pleasant, crisp fall feel across the region.
Tuesday:
North winds will ease slightly but remain gusty in higher elevations, particularly in the Santa Ynez Mountains and along the southern coast of Santa Barbara County. This brief break between wind events comes as a small ridge of high pressure moves in, allowing a slight reduction in offshore flow.
Temperatures along the coast and in the valleys may dip a few degrees as a result, but interior regions will warm up by 6-12°F due to the ridge's stabilizing effect. Overall, skies will stay clear, maintaining bright sunshine throughout the day.
Wednesday and Thursday:
A powerful Santa Ana wind event is expected to ramp up mid-week, marking the strongest wind episode of the season so far. Another upper-level low is forecast to settle into the region from the Canadian Plains, which will intensify the pressure gradient over Southern California, driving this Santa Ana event. Winds will peak between Wednesday night and Thursday, with gusts likely exceeding 50 mph in prone areas of Ventura and Los Angeles Counties. Though the strongest winds are expected to the south, breezy conditions will reach portions of San Luis Obispo and Santa Barbara Counties, especially in foothill and mountain areas, with gusts up to 40 mph in more exposed areas.
These strong winds carry dry air from the interior and bring critical fire weather conditions, which could elevate fire risks throughout the region. In addition, cold air accompanying this wind event will bring a noticeable drop in interior temperatures by 8-12°F, while coastal and valley areas will see a lesser cooling effect. Clear skies are expected to persist through Thursday, with no rain in the forecast.
Friday through Monday:
Conditions will ease slightly, with offshore flow continuing but at reduced strength. Skies will remain clear, with calm, stable weather taking hold as high pressure regains control. Morning low clouds may return to coastal areas by Sunday as the pressure gradient relaxes. Temperatures are expected to remain steady, with highs in the upper 60s to low 70s along the coast and valleys, which is a touch below normal for this time of year.
Looking ahead to early next week, models suggest that another upper-level low could bring a fresh round of northerly winds around Monday night or Tuesday, potentially renewing gusty conditions for the region. Models are up and down on how much rain will be associated. This afternoon's GFS run got more bullish again. It should be noted this period in the forecast has been something models have battled over since early last week.
