Understanding the Impact of North Pacific High on Northern California's Weather Patterns

Morning Weather Dynamics

The North Pacific High (NPH) influences Northern California's weather by pushing a ridge into the far northern regions in the early morning. This action introduces a small lobe of low-pressure over the Golden Gate area, resulting in an AM eddy and southerly coastal winds.

Mid-Morning Changes

As the morning progresses, the NPH ridge and the associated eddy dissipate, causing the low-pressure zone to retract inland. This shift leaves the Central Valley with a balanced distribution of low-pressure from Sacramento to Bakersfield.

Ocean Wind Patterns

Ocean winds, influenced by this atmospheric change, split into various paths. Some winds curve through the Golden Gate towards Pt. Isabel, Race Track, and Berkeley, turning into WSW winds directed at Sacramento and Stockton. Others flow through the San Bruno Gap, reaching the 3rd Ave. Channel and impacting Stockton and Bakersfield.

Afternoon Wind Behavior

During the afternoon, ocean winds through the Hwy. 92 gaps make their way to the 3rd Ave. launch sites, causing unreliable wind conditions until around 4-6 PM despite strong WNW channel winds. Additionally, the loss of strong west winds at approximately 1000 feet aloft (975 MB) results in delayed and less gusty surface winds.

Final Thoughts

The interplay between the North Pacific High and low-pressure systems significantly impacts Northern California's weather. Understanding these patterns helps predict wind behavior and its effects on different regions, providing valuable insights for weather forecasting and planning.